feat: phase 3-5 — workflow engine, background subagents, multi-modal, cache shape, inline diff

Phase 3: Dynamic Workflow Engine
- VM sandbox (node:vm) with agent/parallel/pipeline API, Claude Code compatible
- Workflow file discovery (.boocode/workflows/*.js + ~/.boocode/workflows/*.js)
- Workflow manager with session/chat creation and inference dispatch
- Built-in catalog: deep-research, review-code, find-issues
- Resumability cache: SHA-256 hash of agent spec, in-memory Map

Phase 4: Background Subagents
- background-task.ts service: spawn/poll/cancel lifecycle
- spawn_subagent, subagent_status, subagent_result tools in ALL_TOOLS

Phase 5: Multi-modal + Cache Shape
- Multi-modal stub with type defs and hook point in payload.ts
- CacheShapeBadge component in trace viewer (colored bar + %)

.omo/drafts/workflow-engine-design.md

@@ -0,0 +1,55 @@
+# Dynamic Workflow Engine — Design
+
+## Architecture
+
+```
+User writes workflow JS file:
+.boocode/workflows/my-flow.js
+
+Workflow Runtime (apps/server)
+  ├── isolated-vm sandbox (or node:vm)
+  ├── API surface: agent(), parallel(), pipeline(), phase(), budget()
+  ├── Tool bridge → BooCode's existing tool set
+  ├── Workflow manager (concurrency, lifecycle)
+  ├── Resumability cache (SHA-256 of agent spec)
+  └── Catalog (built-in workflows: deep-research, review-code)
+
+Workflow execution:
+  1. User triggers workflow (slash command or Orchestrator panel)
+  2. File discovery finds .boocode/workflows/<name>.js
+  3. Sandbox compiles and executes the script
+  4. agent() calls go through tool bridge → existing inference pipeline
+  5. parallel() spawns concurrent agent calls (max 3 default)
+  6. Results stream via existing WS frames
+  7. Completed agents cached by hash for resume
+
+API Surface (Claude Code compatible):
+  agent(prompt, { label?, schema?, model?, capabilities?, max_tool_calls? })
+  parallel([() => agent(...), () => agent(...)])
+  pipeline(items, ...stages)
+  phase(title)
+  log(message)
+  budget.total / budget.spent() / budget.remaining()
+  args
+  workflow(name, args?)  — one level of nesting
+```
+
+## Implementation Plan
+
+### Phase 1: Core Runtime (this session)
+- Sandbox using Node's `vm` module (no extra deps)
+- `agent()` function that creates a task and waits for completion
+- Workflow file discovery
+- Basic workflow manager
+
+### Phase 2: Advanced Primitives
+- `parallel()` with concurrency limits
+- `pipeline()` streaming
+- `budget()` token tracking
+- Workflow resumability cache
+
+### Phase 3: UI + Polish
+- Integration with Orchestrator panel
+- Built-in workflow catalog
+- Workflow editor
+- Error recovery

.omo/plans/paseo-orchestrator.md

@@ -0,0 +1,239 @@
+# Paseo-like Orchestrator — Implementation Plan
+
+> **Goal:** Transform BooCode into a Paseo-style thin-client orchestration layer with observability, dynamic workflows, resumability, background subagents, multi-modal, and cache shape telemetry.
+>
+> **Architecture:** Durable agent execution engine beneath thin chat/coder frontends. Trace system as foundation, workflow engine as the structural addition, everything else layered on top.
+>
+> **Inspired by:** Paseo (agent lifecycle, worktree isolation), Whale (workflow engine, cache telemetry), OpenCode (session resume), Claude Code (workflow script format).
+
+---
+
+## TL;DR
+
+> **Quick Summary**: Build a durable orchestration layer with trace observability, dynamic JS workflows, session persistence, background subagents, and multi-modal support over 5 phases.
+>
+> **Deliverables**:
+> - Trace system with DB persistence + viewer UI
+> - Dynamic workflow engine (JS sandbox, agent/parallel/pipeline)
+> - Workflow resumability (hash-based step caching)
+> - Background subagent runtime
+> - Session persistence across refreshes
+> - Cache shape telemetry (DeepSeek KV cache viz)
+> - Multi-modal attachment support
+>
+> **Estimated Effort**: XL — 5 phases, ~2-3 weeks total
+> **Parallel Execution**: YES — phases 1-2 can partially overlap
+> **Critical Path**: Trace system → Workflow engine → All downstream features
+
+---
+
+## Context
+
+### Original Request
+User wants BooCode to become "like Paseo — a thin client" with observability, dynamic workflows, session persistence, background agents, multi-modal, cache shape telemetry, and workflow resumability. They invoked skills across model evaluation, long context, SGLang, LangChain, LangSmith, agentic eval, agent harness construction, agent governance, and chat SDKs — indicating broad ambition for a production-quality AI coding platform.
+
+### Key Decisions
+- **Trace system first**: Foundation for all debugging and optimization
+- **isolated-vm for workflow sandbox**: Node-native, no external deps
+- **DB-backed sessions**: Postgres for trace store + session state
+- **Existing WS frames + new `tool_trace` frame**: Live streaming to frontend
+- **Phase ordering**: Foundation (trace) → UX (persistence) → Power (workflows) → Polish (background/multi-modal/cache)
+
+---
+
+## Phases
+
+### Phase 1: Trace System + Observability
+**Est. effort**: 3-4 days
+
+Core observability infrastructure. Every tool call gets timed, logged, and persisted.
+
+**Deliverables**:
+- `tool_traces` DB table (id, session_id, chat_id, turn_number, tool_name, input, output, started_at, finished_at, latency_ms, tokens_used, cache_tokens, reasoning_tokens, error, outcome)
+- Instrumentation in `tool-phase.ts` wrapping `executeToolCall` with start/end timing
+- `tool_trace` WS frame type for live streaming to frontend
+- GET `/api/chats/:id/traces` endpoint (paginated)
+- Trace viewer pane (collapsible tree, timing bars, expand/collapse per call)
+
+**Files to create**: 5-7 files across server + web + contracts
+**Dependencies**: None — standalone feature
+
+---
+
+### Phase 2: Session Persistence + Resume
+**Est. effort**: 2-3 days
+
+Agent state survives browser refresh. Active sessions can be resumed.
+
+**Deliverables**:
+- Serialize active agent state to DB on each turn boundary
+- Restore state on WS reconnect (existing `snapshot` frame enhanced)
+- Agent session timeline view (history of all turns in a session)
+- Coder pane rehydrates from persisted state
+
+**Files to modify**: ws.ts, useSessionStream.ts, session store, dispatcher
+**Dependencies**: None — standalone, but benefits from Phase 1 trace data
+
+---
+
+### Phase 3: Dynamic Workflow Engine
+**Est. effort**: 5-7 days
+
+JS sandbox for multi-agent orchestration. Claude Code compatible.
+
+**Deliverables**:
+- `isolated-vm` sandbox (or Node `vm` module with restricted context)
+- Workflow API: `agent()`, `parallel()`, `pipeline()`, `phase()`, `budget()`, `log()`, `args`
+- Workflow file discovery (`.boocode/workflows/*.js` → project, `~/.boocode/workflows/*.js` → global)
+- Built-in workflow catalog (deep-research, multi-review, etc.)
+- Workflow manager with concurrency limits, token budgets
+- Integration with existing Orchestrator panel for UI
+
+**Files to create**: 10-15 files (workflow runtime, scheduler, tool bridge, manager, catalog)
+**Dependencies**: Phase 1 traces feed into workflow observability
+
+**Workflow Resumability** (within Phase 3):
+- SHA-256 hash of agent spec (prompt + options)
+- Cache completed results by hash
+- On re-run, skip cached agents, only execute new/changed ones
+- In-memory cache for current session, optional DB persistence
+
+**Est. effort**: 1-2 days within Phase 3
+
+---
+
+### Phase 4: Background Subagents
+**Est. effort**: 2-3 days
+
+Non-blocking subagent execution. `spawn_subagent` returns immediately, results collected later.
+
+**Deliverables**:
+- Background task queue (reuses existing `tasks` table)
+- `spawn_subagent` tool that creates a task and returns immediately
+- `subagent_status` tool to poll completion
+- `subagent_result` tool to retrieve output
+- Background agent pane showing running/completed subagents
+- Notifications via hooks when background tasks complete
+
+**Files to create**: 3-5 files across server + web
+**Dependencies**: Phase 1 traces, Phase 2 session persistence
+
+---
+
+### Phase 5: Multi-modal + Cache Shape (Polish)
+**Est. effort**: 2-3 days
+
+Image/file attachment support + DeepSeek cache hit visualization.
+
+**Deliverables (Multi-modal)**:
+- Image/file attachment storage (tmpfs, referenced in message)
+- Forward image content through DeepSeek API's multimodal support
+- Render attached images in message bubble
+- Model can "see" screenshots, diagrams, UI mocks
+
+**Deliverables (Cache Shape)**:
+- Extract `prompt_cache_hit_tokens` from DeepSeek provider metadata
+- Build cache segment visualization (system prompt, tool schema, conversation)
+- Per-turn cache hit rate in trace viewer
+- Cumulative cache stats in session view
+
+**Files to create**: 3-5 files
+**Dependencies**: Phase 1 traces (for cache shape), existing DeepSeek integration
+
+---
+
+## Execution Strategy
+
+### Parallel Execution Waves
+
+```
+Wave 1 (Start Immediately):
+├── Phase 1: Trace system backend (tool_traces table + instrumentation) [deep]
+├── Phase 1: Trace viewer frontend [visual-engineering]
+└── Phase 2: Session persistence backbone [deep]
+
+Wave 2 (After Wave 1):
+├── Phase 3: Workflow engine sandbox + API surface [deep]
+├── Phase 3: Workflow file discovery + manager [unspecified-high]
+├── Phase 3: Workflow resumability cache [quick]
+└── Phase 4: Background subagent queue + tools [unspecified-high]
+
+Wave 3 (After Wave 2):
+├── Phase 4: Background agent pane + notifications [visual-engineering]
+├── Phase 5: Multi-modal attachment pipeline [deep]
+└── Phase 5: Cache shape telemetry UI [visual-engineering]
+
+Wave FINAL:
+├── F1: Plan compliance audit (oracle)
+├── F2: Code quality review (unspecified-high)
+├── F3: Integration QA (unspecified-high)
+└── F4: Scope fidelity check (deep)
+```
+
+---
+
+## TODOs
+
+> Phase 1: Trace System + Observability
+
+- [ ] 1. Create tool_traces DB table + migration
+
+- [ ] 2. Add tool_trace WS frame + contracts schema
+
+- [ ] 3. Instrument tool-phase.ts with start/end timing
+
+- [ ] 4. Add GET /api/chats/:id/traces endpoint
+
+- [ ] 5. Build trace viewer frontend component
+
+> Phase 2: Session Persistence + Resume
+
+- [ ] 6. Serialize agent state to DB on turn boundaries
+
+- [ ] 7. Restore state on WS reconnect
+
+- [ ] 8. Agent session timeline view
+
+> Phase 3: Dynamic Workflow Engine
+
+- [ ] 9. Create isolated-vm workflow sandbox
+
+- [ ] 10. Implement agent/parallel/pipeline primitives
+
+- [ ] 11. Workflow file discovery system
+
+- [ ] 12. Workflow manager + built-in catalog
+
+- [ ] 13. Workflow resumability (hash-based cache)
+
+- [ ] 14. Workflow UI integration with Orchestrator panel
+
+> Phase 4: Background Subagents
+
+- [ ] 15. Background task queue + spawn_subagent tool
+
+- [ ] 16. subagent_status + subagent_result tools
+
+- [ ] 17. Background agent pane
+
+> Phase 5: Multi-modal + Cache Shape
+
+- [ ] 18. Multi-modal attachment pipeline
+
+- [ ] 19. Image render in message bubble
+
+- [ ] 20. Cache shape telemetry data pipeline
+
+- [ ] 21. Cache shape visualization in trace viewer
+
+---
+
+## Success Criteria
+
+- Tool trace viewer shows every call with timing bars and token costs
+- Browser refresh preserves agent session state
+- Workflow scripts run in isolated sandbox with agent/parallel/pipeline
+- Re-running a workflow skips cached agents (hash-based)
+- Background subagents run independently, results collected later
+- Model can see attached images in chat
+- Cache hit rate visible per-turn and cumulative

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 All notable changes per release tag. Most recent on top, ordered by tag creation date (which matches the git history). Tag names follow `vMAJOR.MINOR.PATCH-slug` — the slug describes what shipped, so the tag name alone is enough to recall the batch.
 
+## v2.8.18-deepseek-whale-lift — 2026-06-08
+
+Integrates DeepSeek API directly into BooChat and BooCoder via `@ai-sdk/deepseek`, replacing the generic `openai-compatible` wrapper. DeepSeek V4 models (`deepseek-v4-flash`, `deepseek-v4-pro`) with configurable thinking effort levels appear in both chat and coder pane model pickers. Full token tracking — cache hit tokens and reasoning tokens — flow from the API through new DB columns and WS frames into the UI message stats line. Lifts three high-value features from the Whale codebase: a schema-based tool input repair system that coerces types and unwraps markdown autolinks before Zod validation, a shell-based lifecycle hooks system (PreToolUse, PostToolUse, Stop, PreCompact, PostCompact) with JSON stdin/stdout contract, and per-MCP-server permissions (allow/ask/deny) gating tool execution.
+
 ## v2.8.0-fork-lifts — 2026-06-07
 
 Completes the eight fork-lift integrations from `/opt/forks` into BooCode: boocontext sidecar upgrade, LSP code intelligence, DCP clean-room pruning, institutional memory, subagent protocol enhancements, plugin hook host, inference reliability (tool-shim + loop detectors), and TokenScope token breakdown. Backfills edit safety guards (truncation + dropped imports) and the TokenScope analyzer/persist module. Closes the fork-lifts-mit epic.

apps/booterm/src/index.ts

@@ -5,6 +5,7 @@ import { getPool, closeDb } from './db.js';
 import { registerHealthRoutes } from './routes/health.js';
 import { registerTerminalRoutes } from './routes/terminals.js';
 import { registerSessionRoutes } from './routes/sessions.js';
+import { registerSearchRoutes } from './routes/search.js';
 import { registerWsAttachRoute } from './ws/attach.js';
 
 async function main(): Promise<void> {
@@ -35,6 +36,7 @@ async function main(): Promise<void> {
   registerHealthRoutes(app);
   registerTerminalRoutes(app, config.TMUX_CONF_PATH);
   registerSessionRoutes(app);
+  registerSearchRoutes(app, config.TMUX_CONF_PATH);
   registerWsAttachRoute(app, config.TMUX_CONF_PATH);
 
   const shutdown = async (signal: string) => {

apps/booterm/src/pty/registry.ts

@@ -33,6 +33,7 @@ export function register(
 
 export function unregister(paneId: string): void {
   sessions.delete(paneId);
+  ringBuffers.delete(paneId);
 }
 
 export function list(): SessionMeta[] {
@@ -42,3 +43,120 @@ export function list(): SessionMeta[] {
 export function get(paneId: string): SessionMeta | undefined {
   return sessions.get(paneId);
 }
+
+// ── Ring buffer for PTY output search ──────────────────────────────────────
+
+export interface SearchMatch {
+  line: number;
+  content: string;
+  contextBefore: string[];
+  contextAfter: string[];
+}
+
+const ringBuffers = new Map<string, string[]>();
+
+/**
+ * Append raw PTY data to the ring buffer for a given pane.
+ * Splits incoming data on newlines and pushes each line into the buffer,
+ * trimming to `maxLines` (default 5000) from the tail.
+ */
+export function appendOutput(
+  paneId: string,
+  data: string,
+  maxLines: number = 5000,
+): void {
+  let buf = ringBuffers.get(paneId);
+  if (!buf) {
+    buf = [];
+    ringBuffers.set(paneId, buf);
+  }
+
+  // Split on newlines — each chunk may contain multiple complete lines and
+  // potentially a trailing partial line (which we store as-is; the next chunk
+  // will either complete it or be another partial).
+  const lines = data.split('\n');
+
+  // The first element of `lines` may be a continuation of the last partial
+  // line from the previous append. If the buffer is non-empty and the last
+  // stored entry is a partial (no trailing newline previously), glue them.
+  // We detect "partial" by checking whether `data` ended with '\n' — if it
+  // did, the last element after split is '' (empty) which we drop.
+  const endedWithNewline = data.endsWith('\n');
+  if (endedWithNewline) {
+    // The final empty-string element is discarded.
+    lines.pop();
+  }
+
+  if (buf.length > 0 && lines.length > 0) {
+    // Concatenate the last partial line in the buffer with the first split
+    // segment. This avoids splitting ANSI sequences or text across chunks.
+    buf[buf.length - 1] = (buf[buf.length - 1] ?? '') + (lines[0] ?? '');
+    lines.shift();
+  }
+
+  for (const line of lines) {
+    buf.push(line);
+  }
+
+  // Trim from head if over maxLines
+  if (buf.length > maxLines) {
+    buf = buf.slice(buf.length - maxLines);
+    ringBuffers.set(paneId, buf);
+  }
+}
+
+/**
+ * Search the ring buffer for a pane using a regex pattern.
+ * Returns matches with optional context lines before and after each match.
+ */
+export function searchRingBuffer(
+  paneId: string,
+  pattern: string,
+  opts?: { limit?: number; context?: number },
+): SearchMatch[] {
+  const buf = ringBuffers.get(paneId);
+  if (!buf || buf.length === 0) return [];
+
+  const limit = opts?.limit ?? 50;
+  const context = opts?.context ?? 0;
+
+  let re: RegExp;
+  try {
+    re = new RegExp(pattern, 'u');
+  } catch {
+    return []; // invalid regex — caller should validate, but be defensive
+  }
+
+  const results: SearchMatch[] = [];
+
+  for (let i = 0; i < buf.length; i++) {
+    if (results.length >= limit) break;
+    if (re.test(buf[i]!)) {
+      const contextBefore: string[] = [];
+      const contextAfter: string[] = [];
+      for (let c = 1; c <= context; c++) {
+        const ci = i - c;
+        if (ci >= 0) contextBefore.unshift(buf[ci]!);
+      }
+      for (let c = 1; c <= context; c++) {
+        const ci = i + c;
+        if (ci < buf.length) contextAfter.push(buf[ci]!);
+      }
+      results.push({
+        line: i + 1, // 1-based line number for display
+        content: buf[i]!,
+        contextBefore,
+        contextAfter,
+      });
+    }
+  }
+
+  return results;
+}
+
+/**
+ * Remove the ring buffer for a pane. Called on session kill / pane close.
+ */
+export function clearBuffer(paneId: string): void {
+  ringBuffers.delete(paneId);
+}

apps/booterm/src/routes/search.ts

@@ -0,0 +1,167 @@
+import type { FastifyInstance } from 'fastify';
+import { z } from 'zod';
+import { sanitizeId, tmuxSessionName, capturePane } from '../pty/manager.js';
+import { searchRingBuffer, clearBuffer } from '../pty/registry.js';
+
+const ParamsSchema = z.object({
+  sid: z.string(),
+  pid: z.string(),
+});
+
+const MAX_PATTERN_LENGTH = 200;
+
+// Zod-refined string: reject empty and overly-long patterns to prevent ReDoS
+const PatternQuerySchema = z
+  .string()
+  .min(1, 'pattern is required')
+  .max(MAX_PATTERN_LENGTH, `pattern must not exceed ${MAX_PATTERN_LENGTH} characters`);
+
+const QuerySchema = z.object({
+  pattern: PatternQuerySchema,
+  limit: z.coerce.number().int().min(1).max(500).default(50),
+  context: z.coerce.number().int().min(0).max(50).default(0),
+});
+
+interface SearchMatch {
+  line: number;
+  content: string;
+  contextBefore: string[];
+  contextAfter: string[];
+}
+
+interface SearchResponse {
+  matches: SearchMatch[];
+  total: number;
+  truncated: boolean;
+  source: 'ring' | 'capture';
+}
+
+/**
+ * Search a captured pane buffer using a regex. This is the fallback path
+ * when the ring buffer doesn't have enough matches.
+ */
+function grepBuffer(
+  text: string,
+  pattern: string,
+  limit: number,
+  context: number,
+): SearchMatch[] {
+  let re: RegExp;
+  try {
+    re = new RegExp(pattern, 'u');
+  } catch {
+    return [];
+  }
+
+  const lines = text.split('\n');
+  const results: SearchMatch[] = [];
+
+  for (let i = 0; i < lines.length; i++) {
+    if (results.length >= limit) break;
+    if (re.test(lines[i]!)) {
+      const contextBefore: string[] = [];
+      const contextAfter: string[] = [];
+      for (let c = 1; c <= context; c++) {
+        const ci = i - c;
+        if (ci >= 0) contextBefore.unshift(lines[ci]!);
+      }
+      for (let c = 1; c <= context; c++) {
+        const ci = i + c;
+        if (ci < lines.length) contextAfter.push(lines[ci]!);
+      }
+      results.push({
+        line: i + 1,
+        content: lines[i]!,
+        contextBefore,
+        contextAfter,
+      });
+    }
+  }
+
+  return results;
+}
+
+export function registerSearchRoutes(app: FastifyInstance, tmuxConfPath: string): void {
+  app.get<{
+    Params: { sid: string; pid: string };
+    Querystring: { pattern?: string; limit?: string; context?: string };
+  }>(
+    '/api/term/sessions/:sid/panes/:pid/search',
+    async (req, reply) => {
+      const p = ParamsSchema.safeParse(req.params);
+      if (!p.success) return reply.code(400).send({ error: 'bad_params' });
+
+      const sid = sanitizeId(p.data.sid);
+      const pid = sanitizeId(p.data.pid);
+      if (!sid || !pid) return reply.code(400).send({ error: 'bad_id_format' });
+
+      const q = QuerySchema.safeParse(req.query);
+      if (!q.success) {
+        return reply.code(400).send({
+          error: 'bad_query',
+          details: q.error.flatten().fieldErrors,
+        });
+      }
+
+      const { pattern, limit, context } = q.data;
+
+      // ── Path 1: ring buffer search (fast, no tmux interaction) ──
+      const ringMatches = searchRingBuffer(pid, pattern, { limit, context });
+      if (ringMatches.length >= limit) {
+        return reply.code(200).send({
+          matches: ringMatches,
+          total: ringMatches.length,
+          truncated: ringMatches.length >= limit,
+          source: 'ring' as const,
+        });
+      }
+
+      // ── Path 2: capture-pane + grep fallback (10s timeout) ──
+      const sessionName = tmuxSessionName(pid);
+
+      let capture: string;
+      try {
+        capture = await withTimeout(
+          capturePane(tmuxConfPath, sessionName, 5000),
+          10_000,
+        );
+      } catch (err) {
+        req.log.warn({ err, pid }, 'capture-pane timed out or failed');
+        return reply.code(200).send({
+          matches: ringMatches,
+          total: ringMatches.length,
+          truncated: false,
+          source: 'ring' as const,
+        });
+      }
+
+      if (!capture) {
+        // tmux pane may no longer exist — return whatever ring had
+        return reply.code(200).send({
+          matches: ringMatches,
+          total: ringMatches.length,
+          truncated: false,
+          source: 'ring' as const,
+        });
+      }
+
+      const captureMatches = grepBuffer(capture, pattern, limit, context);
+
+      return reply.code(200).send({
+        matches: captureMatches,
+        total: captureMatches.length,
+        truncated: captureMatches.length >= limit,
+        source: 'capture' as const,
+      });
+    },
+  );
+}
+
+function withTimeout<T>(promise: Promise<T>, ms: number): Promise<T> {
+  return Promise.race([
+    promise,
+    new Promise<never>((_, reject) =>
+      setTimeout(() => reject(new Error('timeout')), ms),
+    ),
+  ]);
+}

apps/booterm/src/ws/attach.ts

@@ -9,7 +9,7 @@ import {
 } from '../pty/manager.js';
 import { attachPty } from '../pty/pty.js';
 import { getUser } from '../auth.js';
-import { register, unregister } from '../pty/registry.js';
+import { register, unregister, appendOutput } from '../pty/registry.js';
 
 export function registerWsAttachRoute(app: FastifyInstance, tmuxConfPath: string): void {
   app.get<{
@@ -106,6 +106,8 @@ export function registerWsAttachRoute(app: FastifyInstance, tmuxConfPath: string
         } catch (err) {
           req.log.warn({ err }, 'ws send failed');
         }
+        // Feed the ring buffer for pattern-based search
+        appendOutput(pid, data);
       };
       handle.onData(onData);
 

apps/coder/src/conductor/types.ts

@@ -38,10 +38,31 @@ export interface StepContext {
   readonly model?: string;
 }
 
-export type StepKind = 'agent' | 'code' | 'approval';
+export type StepKind = 'agent' | 'code' | 'approval' | 'switch';
+
+/**
+ * One branch of a SWITCH step. The first case whose condition evaluates to true
+ * is selected; all other branches' stepIds are excluded from execution.
+ */
+export interface SwitchCase {
+  /** Human-readable label for this branch (reported in switch output). */
+  label: string;
+  /** Pure guard — called with the current step context to decide this branch. */
+  condition: (ctx: StepContext) => boolean;
+  /** stepIds belonging to this branch. */
+  stepIds: string[];
+}
 
 export type TriggerRule = 'all_success' | 'one_success' | 'all_done';
 
+/** Possible statuses for a flow step (persisted in flow_steps.status). */
+export type StepStatus = 'pending' | 'running' | 'completed' | 'failed' | 'skipped' | 'cancelled' | 'timed_out';
+
+/** Retry policy for a step that times out. */
+export interface RetryConfig {
+  maxRetries: number;
+}
+
 export interface Step {
   /** unique id within the flow; other steps depend on it by this id */
   id: string;
@@ -55,10 +76,19 @@ export interface Step {
   /**
    * For kind:'agent', returns the worker PROMPT (task + any prior outputs).
    * For kind:'code', returns the step RESULT directly (the fold/transform).
+   * For kind:'switch', unused (the runner evaluates cases internally).
    */
   run: (ctx: StepContext) => string | Promise<string>;
   /** optional guard — when it returns false the step is skipped (e.g. no repo) */
   when?: (ctx: StepContext) => boolean;
+  /** max retries on timeout (0 or unset = no retry) */
+  maxRetries?: number;
+  /** batch group id; steps sharing the same batch are gated by batchConfig.maxConcurrent */
+  batch?: string;
+  /** for kind:'switch' — ordered list of branches evaluated in declaration order */
+  cases?: SwitchCase[];
+  /** for kind:'switch' — fallback step ids when no case matches */
+  defaultBranch?: string[];
 }
 
 export interface Flow {
@@ -69,6 +99,8 @@ export interface Flow {
   render: (ctx: StepContext) => string;
   /** optional output filename for the artifact, derived from input */
   output?: (ctx: StepContext) => string;
+  /** batch parallelism control — gates concurrent dispatch of steps sharing the same batch id */
+  batchConfig?: { maxConcurrent: number; timeoutMs?: number; joinRule?: TriggerRule };
 }
 
 export interface RunResult {

apps/coder/src/config.ts

@@ -52,6 +52,9 @@ const ConfigSchema = z.object({
   ORPHAN_WORKTREE_GRACE_MS: z.coerce.number().int().positive().default(3_600_000),
   DEEPSEEK_API_KEY: z.string().optional(),
   DEEPSEEK_BASE_URL: z.string().url().default('https://api.deepseek.com'),
+  // v2.9.x: flow step timeout (default 5 min). When a 'running' step exceeds
+  // this duration, it is marked 'timed_out' and may be retried.
+  FLOW_STEP_TIMEOUT_MS: z.coerce.number().int().positive().default(300_000),
 });
 
 export type Config = z.infer<typeof ConfigSchema>;

apps/coder/src/schema.sql

@@ -266,7 +266,7 @@ CREATE INDEX IF NOT EXISTS claude_session_entries_key_idx ON claude_session_entr
 -- replaces it with the three-value list).
 ALTER TABLE agent_sessions DROP CONSTRAINT IF EXISTS agent_sessions_backend_chk;
 ALTER TABLE agent_sessions ADD CONSTRAINT agent_sessions_backend_chk
-  CHECK (backend IN ('opencode_server', 'acp_warm', 'claude_sdk'));
+  CHECK (backend IN ('opencode_server', 'acp_warm', 'claude_sdk', 'paseo'));
 
 -- LISTEN/NOTIFY fast path: every tasks INSERT (from any call site — routes,
 -- new_task tool, MCP server) fires pg_notify('tasks_new') in the same
@@ -340,11 +340,12 @@ CREATE INDEX IF NOT EXISTS flow_steps_task_id_idx ON flow_steps(task_id);
 -- edits above are no-ops on the existing DB (CREATE TABLE IF NOT EXISTS skips an
 -- existing table) — widen via the repo's DROP-IF-EXISTS → guarded-ADD discipline.
 -- Pure ADD of a new allowed value, so no row UPDATE is needed (no value renamed).
+-- v2.9.x: widen status CHECKs to include 'timed_out' for Task State Machine.
 ALTER TABLE flow_runs DROP CONSTRAINT IF EXISTS flow_runs_status_chk;
 DO $$ BEGIN
   IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'flow_runs_status_chk') THEN
     ALTER TABLE flow_runs ADD CONSTRAINT flow_runs_status_chk
-      CHECK (status IN ('running', 'completed', 'failed', 'cancelled'));
+      CHECK (status IN ('running', 'completed', 'failed', 'cancelled', 'timed_out'));
   END IF;
 END $$;
 
@@ -352,10 +353,14 @@ ALTER TABLE flow_steps DROP CONSTRAINT IF EXISTS flow_steps_status_chk;
 DO $$ BEGIN
   IF NOT EXISTS (SELECT 1 FROM pg_constraint WHERE conname = 'flow_steps_status_chk') THEN
     ALTER TABLE flow_steps ADD CONSTRAINT flow_steps_status_chk
-      CHECK (status IN ('pending', 'running', 'completed', 'failed', 'skipped', 'cancelled'));
+      CHECK (status IN ('pending', 'running', 'completed', 'failed', 'skipped', 'cancelled', 'timed_out'));
   END IF;
 END $$;
 
+-- Task State Machine: retry columns for flow_steps.
+ALTER TABLE flow_steps ADD COLUMN IF NOT EXISTS retry_count INTEGER NOT NULL DEFAULT 0;
+ALTER TABLE flow_steps ADD COLUMN IF NOT EXISTS max_retries INTEGER;
+
 -- Arena: battles + contestants + cross_examinations.
 -- project_id carries no FK (matches tasks.project_id + flow_runs.project_id convention).
 -- winner_contestant_id FK is deferred (forward reference): added via guarded ALTER below.

apps/coder/src/services/__tests__/flow-runner-decisions.test.ts

@@ -1,16 +1,20 @@
 import { describe, it, expect } from 'vitest';
 import type { Flow, Step, StepContext } from '../../conductor/types.js';
 import {
+  buildBatchState,
+  getReadyInBatch,
   manifestSteps,
-  readySteps,
   partitionReady,
+  readySteps,
   isRunComplete,
   isStuck,
   reconcileResumeStep,
   reconcileRun,
+  resolveSwitch,
   shouldFailOnMissingAgent,
   type SchedulerState,
 } from '../flow-runner-decisions.js';
+import type { StepContext } from '../../conductor/types.js';
 
 /**
  * The DB-driven flow-runner replaces the Phase-1 in-memory wave scheduler
@@ -52,6 +56,8 @@ const emptyState = (over: Partial<SchedulerState> = {}): SchedulerState => ({
   skipped: new Set(),
   inFlight: new Set(),
   excluded: new Set(),
+  timedOut: new Set(),
+  switchResults: new Map(),
   ...over,
 });
 
@@ -237,6 +243,442 @@ describe('isRunComplete / isStuck', () => {
   });
 });
 
+// ─── SWITCH branching (v2.9) ─────────────────────────────────────────────────
+
+describe('resolveSwitch', () => {
+  const baseCtx: StepContext = { input: { question: 'q', band: 'small' }, results: {} };
+
+  it('selects the first matching case and excludes other branches', () => {
+    const step: Step = {
+      id: 'router',
+      kind: 'switch',
+      run: () => '',
+      cases: [
+        { label: 'a', condition: () => false, stepIds: ['a1', 'a2'] },
+        { label: 'b', condition: () => true, stepIds: ['b1', 'b2'] },
+        { label: 'c', condition: () => true, stepIds: ['c1', 'c2'] },
+      ],
+    };
+    const result = resolveSwitch(step, baseCtx);
+    expect(result.chosenCase).toBe('b');
+    expect(result.excluded).toEqual(['a1', 'a2', 'c1', 'c2']);
+  });
+
+  it('falls back to defaultBranch when no case matches', () => {
+    const step: Step = {
+      id: 'router',
+      kind: 'switch',
+      run: () => '',
+      cases: [
+        { label: 'x', condition: () => false, stepIds: ['x1'] },
+        { label: 'y', condition: () => false, stepIds: ['y1'] },
+      ],
+      defaultBranch: ['z1', 'z2'],
+    };
+    const result = resolveSwitch(step, baseCtx);
+    expect(result.chosenCase).toBeNull();
+    // Only case branch steps are excluded; default steps are not.
+    expect(result.excluded).toEqual(['x1', 'y1']);
+  });
+
+  it('excludes all branch steps when no case matches and no default', () => {
+    const step: Step = {
+      id: 'router',
+      kind: 'switch',
+      run: () => '',
+      cases: [
+        { label: 'p', condition: () => false, stepIds: ['p1'] },
+        { label: 'q', condition: () => false, stepIds: ['q1', 'q2'] },
+      ],
+    };
+    const result = resolveSwitch(step, baseCtx);
+    expect(result.chosenCase).toBeNull();
+    expect(result.excluded).toEqual(['p1', 'q1', 'q2']);
+  });
+
+  it('excludes defaultBranch when a case matched', () => {
+    const step: Step = {
+      id: 'router',
+      kind: 'switch',
+      run: () => '',
+      cases: [
+        { label: 'hit', condition: () => true, stepIds: ['h1'] },
+        { label: 'miss', condition: () => false, stepIds: ['m1'] },
+      ],
+      defaultBranch: ['d1'],
+    };
+    const result = resolveSwitch(step, baseCtx);
+    expect(result.chosenCase).toBe('hit');
+    expect(result.excluded).toEqual(['m1', 'd1']);
+  });
+
+  it('returns empty excluded for a degenerate switch with no cases and no default', () => {
+    const step: Step = {
+      id: 'noop',
+      kind: 'switch',
+      run: () => '',
+    };
+    const result = resolveSwitch(step, baseCtx);
+    expect(result.chosenCase).toBeNull();
+    expect(result.excluded).toEqual([]);
+  });
+
+  it('uses ctx.results in condition evaluation', () => {
+    const step: Step = {
+      id: 'router',
+      kind: 'switch',
+      run: () => '',
+      cases: [
+        { label: 'has', condition: (ctx) => ctx.results['prev'] === 'yes', stepIds: ['yes-branch'] },
+        { label: 'no', condition: () => true, stepIds: ['no-branch'] },
+      ],
+    };
+    const ctxWithResult: StepContext = { input: { question: 'q', band: 'small' }, results: { prev: 'yes' } };
+    const result = resolveSwitch(step, ctxWithResult);
+    expect(result.chosenCase).toBe('has');
+    expect(result.excluded).toEqual(['no-branch']);
+  });
+});
+
+describe('readySteps with switch-excluded steps', () => {
+  // Flow: switch router → branch-a/branch-b → fold
+  function switchFlow(): Flow {
+    const steps: Step[] = [
+      {
+        id: 'switch', kind: 'switch', run: () => '',
+        cases: [
+          { label: 'a', condition: () => true, stepIds: ['branch-a'] },
+          { label: 'b', condition: () => false, stepIds: ['branch-b'] },
+        ],
+      },
+      { id: 'branch-a', kind: 'agent', agent: 'x', deps: ['switch'], run: () => 'p' },
+      { id: 'branch-b', kind: 'agent', agent: 'y', deps: ['switch'], run: () => 'q' },
+      { id: 'fold', kind: 'code', deps: ['branch-a', 'branch-b'], run: () => 'r' },
+    ];
+    return { name: 'switch-demo', description: '', steps, render: () => '' };
+  }
+
+  it('excludes non-selected branch steps and treats them as satisfied deps', () => {
+    const flow = switchFlow();
+    // switch completed, branch-b excluded by switch (branch-a selected)
+    const switchResult = new Map<string, { chosenCase: string | null; excluded: Set<string> }>([
+      ['switch', { chosenCase: 'a', excluded: new Set(['branch-b']) }],
+    ]);
+    const state: SchedulerState = {
+      done: new Set(['switch']),
+      skipped: new Set(),
+      inFlight: new Set(),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: switchResult,
+    };
+    const ready = readySteps(flow, state).map((s) => s.id);
+    // branch-a is ready (dep switch is done), branch-b is excluded
+    expect(ready).toContain('branch-a');
+    expect(ready).not.toContain('branch-b');
+  });
+
+  it('fold unblocks once selected branch completes (excluded branch satisfied)', () => {
+    const flow = switchFlow();
+    const switchResult = new Map<string, { chosenCase: string | null; excluded: Set<string> }>([
+      ['switch', { chosenCase: 'a', excluded: new Set(['branch-b']) }],
+    ]);
+    const state: SchedulerState = {
+      done: new Set(['switch', 'branch-a']),
+      skipped: new Set(),
+      inFlight: new Set(),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: switchResult,
+    };
+    const ready = readySteps(flow, state).map((s) => s.id);
+    // fold's deps: branch-a done, branch-b excluded (via switch) → satisfied
+    expect(ready).toContain('fold');
+  });
+
+  it('fold stays blocked until selected branch completes, even with excluded dep', () => {
+    const flow = switchFlow();
+    const switchResult = new Map<string, { chosenCase: string | null; excluded: Set<string> }>([
+      ['switch', { chosenCase: 'a', excluded: new Set(['branch-b']) }],
+    ]);
+    const state: SchedulerState = {
+      done: new Set(['switch']),
+      skipped: new Set(),
+      inFlight: new Set(['branch-a']),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: switchResult,
+    };
+    const ready = readySteps(flow, state).map((s) => s.id);
+    // branch-a in flight, branch-b excluded — only branch-a offered
+    expect(ready).not.toContain('fold');
+  });
+
+  it('isRunComplete returns true when switch-excluded steps are the only unsettled', () => {
+    const flow = switchFlow();
+    // All non-excluded steps done; branch-b is excluded via switch
+    const switchResult = new Map<string, { chosenCase: string | null; excluded: Set<string> }>([
+      ['switch', { chosenCase: 'a', excluded: new Set(['branch-b']) }],
+    ]);
+    const state: SchedulerState = {
+      done: new Set(['switch', 'branch-a', 'fold']),
+      skipped: new Set(),
+      inFlight: new Set(),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: switchResult,
+    };
+    expect(isRunComplete(flow, state)).toBe(true);
+    expect(isStuck(flow, state)).toBe(false);
+  });
+
+  it('combines static excluded with switch-excluded', () => {
+    const flow = switchFlow();
+    // band gating excludes branch-b at launch, AND switch also excludes it
+    const switchResult = new Map<string, { chosenCase: string | null; excluded: Set<string> }>([
+      ['switch', { chosenCase: 'a', excluded: new Set(['branch-b']) }],
+    ]);
+    const state: SchedulerState = {
+      done: new Set(['switch', 'branch-a']),
+      skipped: new Set(),
+      inFlight: new Set(),
+      excluded: new Set(['branch-b']),
+      timedOut: new Set(),
+      switchResults: switchResult,
+    };
+    // branch-b excluded both ways; fold sees branch-a done, branch-b excluded
+    const ready = readySteps(flow, state).map((s) => s.id);
+    expect(ready).toContain('fold');
+  });
+});
+
+// ─── Batch parallelism (v2.8.22) ─────────────────────────────────────────────
+
+describe('buildBatchState', () => {
+  it('returns empty map when flow has no batchConfig', () => {
+    const flow: Flow = {
+      name: 'no-batch',
+      description: '',
+      steps: [
+        { id: 'a', kind: 'agent', agent: 'x', run: () => 'p' },
+        { id: 'b', kind: 'code', deps: ['a'], run: () => 'r' },
+      ],
+      render: () => '',
+    };
+    const bs = buildBatchState(flow, new Set());
+    expect(bs.size).toBe(0);
+  });
+
+  it('maps each batch group to its running set and config', () => {
+    const flow: Flow = {
+      name: 'batched',
+      description: '',
+      steps: [
+        { id: 'a1', kind: 'agent', agent: 'x', batch: 'review', run: () => 'p' },
+        { id: 'a2', kind: 'agent', agent: 'y', batch: 'review', run: () => 'q' },
+        { id: 'b1', kind: 'agent', agent: 'z', batch: 'check', run: () => 'r' },
+        { id: 'fold', kind: 'code', deps: ['a1', 'a2', 'b1'], run: () => 's' },
+      ],
+      render: () => '',
+      batchConfig: { maxConcurrent: 2 },
+    };
+    // a1 is in flight → review batch has 1 running, check has 0.
+    const bs = buildBatchState(flow, new Set(['a1']));
+    expect(bs.size).toBe(2);
+
+    const review = bs.get('review');
+    expect(review).toBeDefined();
+    expect([...review!.running]).toEqual(['a1']);
+    expect(review!.maxConcurrent).toBe(2);
+    expect(review!.joinRule).toBe('all_success');
+
+    const check = bs.get('check');
+    expect(check).toBeDefined();
+    expect(check!.running.size).toBe(0);
+    expect(check!.maxConcurrent).toBe(2);
+  });
+
+  it('uses joinRule from batchConfig when provided', () => {
+    const flow: Flow = {
+      name: 'join',
+      description: '',
+      steps: [
+        { id: 'x', kind: 'agent', agent: 'a', batch: 'g1', run: () => 'p' },
+      ],
+      render: () => '',
+      batchConfig: { maxConcurrent: 1, joinRule: 'one_success' },
+    };
+    const bs = buildBatchState(flow, new Set());
+    expect(bs.get('g1')!.joinRule).toBe('one_success');
+  });
+
+  it('ignores steps without a batch field', () => {
+    const flow: Flow = {
+      name: 'mixed',
+      description: '',
+      steps: [
+        { id: 'a', kind: 'agent', agent: 'x', run: () => 'p' },
+        { id: 'b', kind: 'agent', agent: 'y', batch: 'g1', run: () => 'q' },
+      ],
+      render: () => '',
+      batchConfig: { maxConcurrent: 3 },
+    };
+    const bs = buildBatchState(flow, new Set(['a', 'b']));
+    // a is inFlight but has no batch — it does not create an entry
+    expect(bs.size).toBe(1);
+    expect(bs.has('g1')).toBe(true);
+    expect(bs.get('g1')!.running.has('b')).toBe(true);
+    // a is not in any batch entry
+    for (const entry of bs.values()) {
+      expect(entry.running.has('a')).toBe(false);
+    }
+  });
+});
+
+describe('getReadyInBatch', () => {
+  function makeBatchState(
+    overrides?: Map<string, { running: Set<string>; maxConcurrent: number; joinRule: TriggerRule }>,
+  ): Map<string, { running: Set<string>; maxConcurrent: number; joinRule: TriggerRule }> {
+    return overrides ?? new Map();
+  }
+
+  it('passes all steps through when batchState is empty', () => {
+    const steps: Step[] = [
+      { id: 'a', kind: 'agent', agent: 'x', run: () => 'p' },
+      { id: 'b', kind: 'agent', agent: 'y', batch: 'g1', run: () => 'q' },
+    ];
+    const state: SchedulerState = {
+      done: new Set(),
+      skipped: new Set(),
+      inFlight: new Set(),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: new Map(),
+      batchState: makeBatchState(),
+    };
+    const result = getReadyInBatch(steps, state, {} as Flow);
+    expect(result.map((s) => s.id)).toEqual(['a', 'b']);
+  });
+
+  it('passes non-batched steps through regardless of batch capacity', () => {
+    const batchState = new Map();
+    batchState.set('g1', { running: new Set(['a']), maxConcurrent: 1, joinRule: 'all_success' });
+    const steps: Step[] = [
+      { id: 'nobatch', kind: 'agent', agent: 'z', run: () => 'r' },
+      { id: 'batched', kind: 'agent', agent: 'x', batch: 'g1', run: () => 'p' },
+    ];
+    const state: SchedulerState = {
+      done: new Set(),
+      skipped: new Set(),
+      inFlight: new Set(['a']),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: new Map(),
+      batchState,
+    };
+    const result = getReadyInBatch(steps, state, {} as Flow);
+    // nobatch passes, batched is at maxConcurrent=1 with a already running → blocked
+    expect(result.map((s) => s.id)).toEqual(['nobatch']);
+  });
+
+  it('allows batch steps up to maxConcurrent', () => {
+    const batchState = new Map();
+    batchState.set('g1', { running: new Set(), maxConcurrent: 2, joinRule: 'all_success' });
+    const steps: Step[] = [
+      { id: 's1', kind: 'agent', agent: 'x', batch: 'g1', run: () => 'p' },
+      { id: 's2', kind: 'agent', agent: 'y', batch: 'g1', run: () => 'q' },
+      { id: 's3', kind: 'agent', agent: 'z', batch: 'g1', run: () => 'r' },
+    ];
+    const state: SchedulerState = {
+      done: new Set(),
+      skipped: new Set(),
+      inFlight: new Set(),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: new Map(),
+      batchState,
+    };
+    // All 0 running, maxConcurrent=2 → all 3 pass through (readySteps would return them,
+    // but the flow-runner dispatches them one-by-one in the agent dispatch loop; getReadyInBatch
+    // is called each tick to allow up to maxConcurrent. Since batch is empty on this tick,
+    // all are allowed — the runner's dispatch loop will put 2 in flight, then next tick blocks.)
+    const result = getReadyInBatch(steps, state, {} as Flow);
+    expect(result.map((s) => s.id)).toEqual(['s1', 's2', 's3']);
+  });
+
+  it('blocks batch steps when at capacity', () => {
+    const batchState = new Map();
+    batchState.set('g1', { running: new Set(['a', 'b']), maxConcurrent: 2, joinRule: 'all_success' });
+    const steps: Step[] = [
+      { id: 'c', kind: 'agent', agent: 'x', batch: 'g1', run: () => 'p' },
+      { id: 'd', kind: 'agent', agent: 'y', batch: 'g1', run: () => 'q' },
+    ];
+    const state: SchedulerState = {
+      done: new Set(),
+      skipped: new Set(),
+      inFlight: new Set(['a', 'b']),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: new Map(),
+      batchState,
+    };
+    // Both batches at capacity → everything filtered out
+    expect(getReadyInBatch(steps, state, {} as Flow)).toEqual([]);
+  });
+
+  it('handles multiple independent batch groups', () => {
+    const batchState = new Map();
+    batchState.set('g1', { running: new Set(['a']), maxConcurrent: 1, joinRule: 'all_success' });
+    batchState.set('g2', { running: new Set(), maxConcurrent: 5, joinRule: 'all_success' });
+    const steps: Step[] = [
+      { id: 'b', kind: 'agent', agent: 'x', batch: 'g1', run: () => 'p' }, // g1 at capacity → blocked
+      { id: 'c', kind: 'agent', agent: 'y', batch: 'g2', run: () => 'q' }, // g2 has room → passes
+      { id: 'd', kind: 'agent', agent: 'z', batch: 'g2', run: () => 'r' }, // g2 has room → passes
+    ];
+    const state: SchedulerState = {
+      done: new Set(),
+      skipped: new Set(),
+      inFlight: new Set(['a']),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: new Map(),
+      batchState,
+    };
+    expect(getReadyInBatch(steps, state, {} as Flow).map((s) => s.id)).toEqual(['c', 'd']);
+  });
+
+  it('lets a step pass when its batch group is known but has no running steps yet', () => {
+    const batchState = new Map();
+    batchState.set('g1', { running: new Set(), maxConcurrent: 2, joinRule: 'all_success' });
+    const steps: Step[] = [
+      { id: 'first', kind: 'agent', agent: 'x', batch: 'g1', run: () => 'p' },
+    ];
+    const state: SchedulerState = {
+      done: new Set(),
+      skipped: new Set(),
+      inFlight: new Set(),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: new Map(),
+      batchState,
+    };
+    expect(getReadyInBatch(steps, state, {} as Flow).map((s) => s.id)).toEqual(['first']);
+  });
+
+  it('handles empty step list gracefully', () => {
+    const state: SchedulerState = {
+      done: new Set(),
+      skipped: new Set(),
+      inFlight: new Set(),
+      excluded: new Set(),
+      timedOut: new Set(),
+      switchResults: new Map(),
+      batchState: makeBatchState(),
+    };
+    expect(getReadyInBatch([], state, {} as Flow)).toEqual([]);
+  });
+});
+
 // ─── Resume reconciliation (D-9) ─────────────────────────────────────────────
 
 describe('reconcileResumeStep', () => {

apps/coder/src/services/__tests__/paseo-client.test.ts

@@ -0,0 +1,195 @@
+import { describe, it, expect, vi } from 'vitest';
+import { PaseoClient, PaseoClientError } from '../paseo-client.js';
+
+/**
+ * Create a PaseoClient whose runCli method is replaced with a mock.
+ * The mock is returned as the second tuple element so tests can
+ * control and inspect it directly.
+ */
+function makeClient(config?: { paseoBin?: string; cliHost?: string }): {
+  client: PaseoClient;
+  mockRunCli: ReturnType<typeof vi.fn>;
+} {
+  const client = new PaseoClient(config);
+  const mockRunCli = vi.fn();
+  (client as any).runCli = mockRunCli;
+  return { client, mockRunCli };
+}
+
+describe('PaseoClient', () => {
+  describe('listAgents', () => {
+    it('returns parsed agent list from paseo ls --json', async () => {
+      const agents = [
+        { id: 'abc-123', shortId: 'abc', name: 'Agent 1', provider: 'opencode', status: 'running' },
+        { id: 'def-456', shortId: 'def', name: 'Agent 2', provider: 'claude', status: 'idle' },
+      ];
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue(JSON.stringify(agents));
+
+      const result = await client.listAgents();
+
+      expect(mockRunCli).toHaveBeenCalledWith(['ls', '--json']);
+      expect(result).toEqual(agents);
+    });
+
+    it('throws PaseoClientError on non-JSON output', async () => {
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue('not json');
+
+      await expect(client.listAgents()).rejects.toThrow(PaseoClientError);
+      await expect(client.listAgents()).rejects.toThrow(/invalid JSON/);
+    });
+
+    it('propagates runCli rejection as-is', async () => {
+      const { client, mockRunCli } = makeClient();
+      const err = new PaseoClientError('ls failed: connection refused', 'ls', 1, 'connection refused');
+      mockRunCli.mockRejectedValue(err);
+
+      await expect(client.listAgents()).rejects.toThrow(PaseoClientError);
+      await expect(client.listAgents()).rejects.toThrow(/ls failed/);
+    });
+  });
+
+  describe('getAgentStatus', () => {
+    it('returns parsed agent detail from paseo inspect --json', async () => {
+      const detail = {
+        Id: 'abc-123', Name: 'Agent 1', Provider: 'opencode',
+        Status: 'idle', Archived: false,
+        CreatedAt: '2026-01-01T00:00:00Z', UpdatedAt: '2026-01-01T01:00:00Z',
+      };
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue(JSON.stringify(detail));
+
+      const result = await client.getAgentStatus('abc-123');
+
+      expect(mockRunCli).toHaveBeenCalledWith(['inspect', '--json', 'abc-123']);
+      expect(result.Id).toBe('abc-123');
+      expect(result.Status).toBe('idle');
+    });
+  });
+
+  describe('health', () => {
+    it('returns ok when paseo ls succeeds', async () => {
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue('[]');
+
+      const result = await client.health();
+
+      expect(result).toEqual({ status: 'ok' });
+    });
+
+    it('returns error when runCli throws', async () => {
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockRejectedValue(new Error('connection refused'));
+
+      const result = await client.health();
+
+      expect(result).toEqual({ status: 'error' });
+    });
+  });
+
+  describe('importAgent', () => {
+    it('calls paseo import with provider and labels', async () => {
+      const agentResult = { Id: 'new-789', Name: 'Imported', Provider: 'opencode', Status: 'idle' };
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue(JSON.stringify(agentResult));
+
+      const result = await client.importAgent('ses-001', 'opencode', {
+        origin: 'boocode',
+        project: 'proj-1',
+      });
+
+      expect(mockRunCli).toHaveBeenCalledWith([
+        'import', '--json',
+        '--provider', 'opencode',
+        '--label', 'origin=boocode',
+        '--label', 'project=proj-1',
+        'ses-001',
+      ]);
+      expect(result.Id).toBe('new-789');
+    });
+
+    it('works without labels', async () => {
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue(JSON.stringify({ Id: 'new-789' }));
+
+      const result = await client.importAgent('ses-001', 'claude');
+
+      expect(mockRunCli).toHaveBeenCalledWith([
+        'import', '--json',
+        '--provider', 'claude',
+        'ses-001',
+      ]);
+      expect(result.Id).toBe('new-789');
+    });
+  });
+
+  describe('archiveAgent', () => {
+    it('calls paseo archive --json', async () => {
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue('{}');
+
+      await client.archiveAgent('abc-123');
+
+      expect(mockRunCli).toHaveBeenCalledWith(['archive', '--json', 'abc-123']);
+    });
+  });
+
+  describe('sendPrompt', () => {
+    it('sends prompt and parses JSON result', async () => {
+      const sendResult = { text: 'Hello!', ok: true };
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue(JSON.stringify(sendResult));
+
+      const result = await client.sendPrompt('abc-123', 'Hello');
+
+      expect(mockRunCli).toHaveBeenCalledWith(['send', '--json', 'abc-123', 'Hello'], undefined);
+      expect(result).toEqual(sendResult);
+    });
+
+    it('falls back to plain text on non-JSON output', async () => {
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue('plain text response');
+
+      const result = await client.sendPrompt('abc-123', 'Hi');
+
+      expect(result).toEqual({ text: 'plain text response', ok: true });
+    });
+
+    it('supports --no-wait flag', async () => {
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue('{}');
+
+      await client.sendPrompt('abc-123', 'Hi', { noWait: true });
+
+      expect(mockRunCli).toHaveBeenCalledWith([
+        'send', '--json', '--no-wait',
+        'abc-123', 'Hi',
+      ], undefined);
+    });
+  });
+
+  describe('stopAgent', () => {
+    it('calls paseo stop', async () => {
+      const { client, mockRunCli } = makeClient();
+      mockRunCli.mockResolvedValue('');
+
+      await client.stopAgent('abc-123');
+
+      expect(mockRunCli).toHaveBeenCalledWith(['stop', 'abc-123']);
+    });
+  });
+
+  describe('cliHost config', () => {
+    it('includes --host flag in args when cliHost is set', async () => {
+      const { client, mockRunCli } = makeClient({ cliHost: 'tcp://localhost:6767?ssl=true' });
+      mockRunCli.mockResolvedValue('[]');
+
+      await client.listAgents();
+
+      expect(mockRunCli).toHaveBeenCalledWith([
+        'ls', '--json', '--host', 'tcp://localhost:6767?ssl=true',
+      ]);
+    });
+  });
+});

apps/coder/src/services/agent-backend.ts

@@ -13,7 +13,7 @@ import type { AcpToolSnapshot } from './acp-tool-snapshot.js';
 import type { AgentCommand } from './provider-types.js';
 
 /** Backend transport kind. Mirrors `agent_sessions.backend` CHECK in schema.sql. */
-export type AgentBackendKind = 'opencode_server' | 'acp_warm' | 'claude_sdk';
+export type AgentBackendKind = 'opencode_server' | 'acp_warm' | 'claude_sdk' | 'paseo';
 
 /**
  * Normalized, transport-agnostic events a backend emits during a turn (§2).

apps/coder/src/services/backends/paseo.ts

@@ -0,0 +1,254 @@
+/**
+ * v2.10 — PaseoBackend: Paseo agent integration for the agent-pool.
+ *
+ * Wraps the Paseo CLI daemon as an AgentBackend. Each Paseo agent maps to one
+ * (chat_id, agent) pair and is persisted via `paseo import` (which registers
+ * an agent with the Paseo daemon). Prompts are sent via `paseo send`, and
+ * the session is cleaned up via `paseo archive`.
+ *
+ * Paseo is a meta-agent hub — it wraps provider sessions (opencode, claude,
+ * acp, etc.). The `provider` option in `EnsureSessionOpts` selects which
+ * provider Paseo delegates to.
+ *
+ * Backend kind: 'paseo' (must be added to agent_sessions_backend_chk).
+ *
+ * Spec: openspec/changes/v2-10-paseo-integration/design.md.
+ */
+import type { FastifyBaseLogger } from 'fastify';
+import type { Sql } from '../../db.js';
+import { PaseoClient, type PaseoSendResult } from '../paseo-client.js';
+import type {
+  AgentBackend,
+  AgentSessionHandle,
+  EnsureSessionOpts,
+  PromptCtx,
+  TurnResult,
+} from '../agent-backend.js';
+
+/** Default provider to use when Paseo wraps a generic agent. */
+const DEFAULT_PASEO_PROVIDER = 'opencode';
+
+export interface PaseoBackendDeps {
+  sql: Sql;
+  log: FastifyBaseLogger;
+  /** The (chat, agent) this backend serves — its pool identity + DB key. */
+  chatId: string;
+  /** Agent name (e.g. 'opencode', 'claude', 'paseo'). */
+  agent: string;
+  /** Resolved PaseoClient instance. */
+  client: PaseoClient;
+  /** Provider string to pass to `paseo import --provider`. */
+  provider: string;
+}
+
+export class PaseoBackend implements AgentBackend {
+  readonly backend = 'paseo' as const;
+
+  private readonly sql: Sql;
+  private readonly log: FastifyBaseLogger;
+  private readonly chatId: string;
+  private readonly agent: string;
+  private readonly client: PaseoClient;
+  private readonly provider: string;
+
+  /** Map of BooCode sessionId → Paseo agent ID. */
+  private readonly agentIds = new Map<string, string>();
+  /** True between prompt() start and settle. */
+  private busy = false;
+  private up = false;
+
+  constructor(deps: PaseoBackendDeps) {
+    this.sql = deps.sql;
+    this.log = deps.log;
+    this.chatId = deps.chatId;
+    this.agent = deps.agent;
+    this.client = deps.client;
+    this.provider = deps.provider || DEFAULT_PASEO_PROVIDER;
+  }
+
+  /** §2: liveness for the health endpoint + dispatcher fallback decision. */
+  health(): 'up' | 'down' {
+    return this.up ? 'up' : 'down';
+  }
+
+  /** Phase 3: busy iff a turn is in flight (pool never evicts a busy backend). */
+  isBusy(): boolean {
+    return this.busy;
+  }
+
+  // ─── ensureSession: create/import a Paseo agent ─────────────────────────────
+
+  async ensureSession(sessionId: string, opts: EnsureSessionOpts): Promise<AgentSessionHandle> {
+    // Check if we already have a Paseo agent ID for this session.
+    let paseoId = this.agentIds.get(sessionId);
+
+    if (!paseoId) {
+      // Resolve existing agent_session_id from DB (e.g. after a restart).
+      const [row] = await this.sql<{ agent_session_id: string | null }[]>`
+        SELECT agent_session_id FROM agent_sessions
+        WHERE chat_id = ${opts.chatId} AND agent = ${opts.agent} AND backend = 'paseo'
+      `;
+      if (row?.agent_session_id) {
+        paseoId = row.agent_session_id;
+        this.agentIds.set(sessionId, paseoId);
+      }
+    }
+
+    if (!paseoId) {
+      // Import a new Paseo agent. Use the session UUID as the provider session id.
+      const labels: Record<string, string> = {
+        origin: 'boocode',
+        project: opts.projectId,
+        chat: opts.chatId,
+        worktree: opts.worktreeId,
+        agent: this.agent,
+      };
+
+      try {
+        const agent = await this.client.importAgent(sessionId, this.provider, labels);
+        paseoId = agent.Id;
+        this.agentIds.set(sessionId, paseoId);
+        this.log.info(
+          { paseoId, agent: this.agent, chatId: this.chatId },
+          'paseo: imported agent',
+        );
+      } catch (err) {
+        this.log.error(
+          { err: String(err), agent: this.agent, chatId: this.chatId },
+          'paseo: importAgent failed',
+        );
+        throw err;
+      }
+    }
+
+    // Upsert the agent_sessions row.
+    await this.sql`
+      INSERT INTO agent_sessions
+        (chat_id, session_id, worktree_id, agent, backend, agent_session_id, server_port, status, last_active_at)
+      VALUES
+        (${opts.chatId}, ${sessionId}, ${opts.worktreeId}, ${opts.agent}, 'paseo', ${paseoId}, NULL, 'active', clock_timestamp())
+      ON CONFLICT (chat_id, agent) DO UPDATE SET
+        session_id = EXCLUDED.session_id,
+        worktree_id = EXCLUDED.worktree_id,
+        backend = 'paseo',
+        agent_session_id = COALESCE(EXCLUDED.agent_session_id, agent_sessions.agent_session_id),
+        server_port = NULL,
+        status = 'active',
+        last_active_at = clock_timestamp()
+    `.catch((err) => {
+      this.log.warn(
+        { err: String(err), chatId: opts.chatId, agent: opts.agent },
+        'paseo: agent_sessions upsert failed (non-fatal)',
+      );
+    });
+
+    this.up = true;
+
+    return {
+      sessionId,
+      agent: opts.agent,
+      backend: 'paseo',
+      chatId: opts.chatId,
+      worktreeId: opts.worktreeId,
+      agentSessionId: paseoId,
+      serverPort: null,
+    };
+  }
+
+  // ─── prompt: send a message to the Paseo agent ─────────────────────────────
+
+  async prompt(handle: AgentSessionHandle, input: string, ctx: PromptCtx): Promise<TurnResult> {
+    const paseoId = handle.agentSessionId;
+    if (!paseoId) {
+      return { ok: false, error: 'paseo: no agent session id in handle' };
+    }
+
+    this.busy = true;
+    try {
+      // Use streamSend for real-time text output via onEvent.
+      const result: PaseoSendResult = await this.client.streamSend(
+        paseoId,
+        input,
+        (event) => {
+          ctx.onEvent(event);
+        },
+        ctx.signal,
+      );
+
+      // Update last_active_at.
+      await this.sql`
+        UPDATE agent_sessions
+        SET last_active_at = clock_timestamp()
+        WHERE chat_id = ${handle.chatId} AND agent = ${handle.agent}
+      `.catch(() => { /* non-fatal */ });
+
+      if (result.error) {
+        return { ok: false, error: result.error };
+      }
+
+      return { ok: true };
+    } catch (err) {
+      const msg = err instanceof Error ? err.message : String(err);
+      // Check if abortion
+      if (ctx.signal.aborted) {
+        return { ok: false, error: 'cancelled' };
+      }
+      return { ok: false, error: `paseo: ${msg}` };
+    } finally {
+      this.busy = false;
+    }
+  }
+
+  // ─── closeSession: archive the Paseo agent ─────────────────────────────────
+
+  async closeSession(handle: AgentSessionHandle): Promise<void> {
+    const paseoId = handle.agentSessionId;
+    if (!paseoId) return;
+
+    try {
+      await this.client.archiveAgent(paseoId);
+      this.log.info({ paseoId, agent: handle.agent }, 'paseo: archived agent');
+    } catch (err) {
+      this.log.warn(
+        { err: String(err), paseoId, agent: handle.agent },
+        'paseo: archiveAgent failed (non-fatal)',
+      );
+    }
+
+    this.agentIds.delete(handle.sessionId);
+
+    // Update DB row.
+    await this.sql`
+      UPDATE agent_sessions
+      SET status = 'closed', last_active_at = clock_timestamp()
+      WHERE chat_id = ${handle.chatId} AND agent = ${handle.agent}
+    `.catch(() => { /* non-fatal */ });
+  }
+
+  // ─── dispose: archive all tracked agents ───────────────────────────────────
+
+  async dispose(): Promise<void> {
+    const ids = [...this.agentIds.values()];
+    this.agentIds.clear();
+
+    for (const paseoId of ids) {
+      try {
+        await this.client.archiveAgent(paseoId);
+      } catch {
+        // Best-effort cleanup during shutdown.
+      }
+    }
+
+    this.up = false;
+  }
+
+  /** Phase 3: periodic health tick — probes the Paseo daemon. */
+  async tickHealth(_now?: number): Promise<void> {
+    try {
+      const h = await this.client.health();
+      this.up = h.status === 'ok';
+    } catch {
+      this.up = false;
+    }
+  }
+}

apps/coder/src/services/collision-detector.ts

@@ -0,0 +1,115 @@
+// v2.8 Collision detection — pure functions that find file overlaps between
+// worktrees/agents editing the same files concurrently. Advisory only; writes
+// are never blocked, but the collision info surfaces in the UI and logs.
+//
+// Severity levels:
+//   same_line     — the same file, exact same line region
+//   adjacent_line — the same file, lines touch or are within 5 lines
+//   different_area — the same file, distant lines
+//
+// Pure functions, no side effects. Testable in isolation.
+
+export type ConflictSeverity = 'same_line' | 'adjacent_line' | 'different_area';
+
+export interface ConflictVerdict {
+  filePath: string;
+  worktrees: string[];
+  severity: ConflictSeverity;
+  agents: string[];
+}
+
+/**
+ * Registry entry for a single file change recorded by a worktree.
+ * Stored in the ConflictIndex Map value for each file path.
+ */
+export interface ConflictEntry {
+  worktreeId: string;
+  agent: string;
+  /**
+   * Approximate line range touched by the change. undefined when the change
+   * creates or deletes the file (full-file collision vs. same-line).
+   */
+  lineRange?: { start: number; end: number };
+  status: 'pending' | 'applied' | 'reverted';
+  timestamp: number;
+}
+
+/**
+ * Shape of the conflict index consumed by findConflicts.
+ * File path → set of entries from different worktrees/agents.
+ */
+export type ConflictIndexData = ReadonlyMap<string, ReadonlySet<ConflictEntry>>;
+
+/**
+ * Find file overlaps between `changedFiles` and the conflict index, excluding
+ * the caller's own worktree.
+ *
+ * Returns one ConflictVerdict per file that has entries from other worktrees.
+ * Severity is the highest found (same_line > adjacent_line > different_area).
+ */
+export function findConflicts(
+  changedFiles: string[],
+  worktreeId: string,
+  /** Approximate line range for the proposed changes, keyed by file path */
+  changedRanges: Map<string, { start: number; end: number }>,
+  conflictIndex: ConflictIndexData,
+): ConflictVerdict[] {
+  const verdicts: ConflictVerdict[] = [];
+
+  for (const filePath of changedFiles) {
+    const entries = conflictIndex.get(filePath);
+    if (!entries || entries.size === 0) continue;
+
+    // Filter to entries from OTHER worktrees
+    const otherEntries = [...entries].filter((e) => e.worktreeId !== worktreeId);
+    if (otherEntries.length === 0) continue;
+
+    const myRange = changedRanges.get(filePath);
+    let severity: ConflictSeverity = 'different_area';
+
+    for (const entry of otherEntries) {
+      if (!myRange || !entry.lineRange) {
+        // Full-file changes (create/delete) always hit at least different_area
+        continue;
+      }
+      const sev = lineOverlapSeverity(myRange, entry.lineRange);
+      if (sev === 'same_line') {
+        severity = 'same_line';
+        break; // Can't get higher than this
+      }
+      if (sev === 'adjacent_line' && severity === 'different_area') {
+        severity = 'adjacent_line';
+      }
+    }
+
+    const worktrees = [...new Set(otherEntries.map((e) => e.worktreeId))];
+    const agents = [...new Set(otherEntries.map((e) => e.agent))];
+
+    verdicts.push({ filePath, worktrees, severity, agents });
+  }
+
+  return verdicts;
+}
+
+const ADJACENT_LINE_THRESHOLD = 5;
+
+/**
+ * Determine severity of overlap between two line ranges.
+ */
+function lineOverlapSeverity(
+  a: { start: number; end: number },
+  b: { start: number; end: number },
+): ConflictSeverity {
+  // Same_line: ranges intersect
+  if (a.start <= b.end && b.start <= a.end) {
+    return 'same_line';
+  }
+
+  // Adjacent: ranges are within ADJACENT_LINE_THRESHOLD lines of each other
+  const gap = a.start > b.end ? a.start - b.end : b.start - a.end;
+  if (gap <= ADJACENT_LINE_THRESHOLD) {
+    return 'adjacent_line';
+  }
+
+  return 'different_area';
+}

apps/coder/src/services/conflict-index.ts

@@ -0,0 +1,151 @@
+// v2.8 In-memory conflict index — tracks which worktrees/agents are editing
+// which files so the collision detector can find overlaps.
+//
+// Singleton exported as `conflictIndex`; imported by pending_changes.ts to
+// register changes at queue time and unregister on worktree teardown.
+//
+// NOT persisted — survives only as long as the BooCoder process. Postgres
+// is the durable record (pending_changes table); this is the hot in-memory
+// probe for concurrent edit warnings.
+
+import type { ConflictEntry, ConflictVerdict } from './collision-detector.js';
+import { findConflicts } from './collision-detector.js';
+
+export class ConflictIndex {
+  /**
+   * filePath → Set of ConflictEntry from various worktrees.
+   * A single worktree may have multiple entries for the same file
+   * (several pending edits to the same file in one session).
+   */
+  #map = new Map<string, Set<ConflictEntry>>();
+
+  // ---- mutation -------------------------------------------------------
+
+  /**
+   * Register that `worktreeId` (agent) is touching `filePath`.
+   * Creates an entry in the index so subsequent callers see it as a conflict.
+   */
+  registerChange(
+    filePath: string,
+    worktreeId: string,
+    agent: string,
+    lineRange?: { start: number; end: number },
+  ): void {
+    let entries = this.#map.get(filePath);
+    if (!entries) {
+      entries = new Set();
+      this.#map.set(filePath, entries);
+    }
+    entries.add({
+      worktreeId,
+      agent,
+      lineRange,
+      status: 'pending' as const,
+      timestamp: Date.now(),
+    });
+  }
+
+  /**
+   * Remove all entries for a given worktree. Called on worktree teardown
+   * so stale entries don't trigger false warnings.
+   */
+  removeWorktree(worktreeId: string): void {
+    for (const [filePath, entries] of this.#map) {
+      const before = entries.size;
+      for (const entry of entries) {
+        if (entry.worktreeId === worktreeId) {
+          entries.delete(entry);
+        }
+      }
+      if (entries.size === 0) {
+        this.#map.delete(filePath);
+      }
+    }
+  }
+
+  /**
+   * Remove entries older than `maxAgeMs`. Useful as a periodic cleanup
+   * when worktree teardown was missed (crash, unclean exit).
+   */
+  sweepStale(maxAgeMs: number): number {
+    const cutoff = Date.now() - maxAgeMs;
+    let removed = 0;
+
+    for (const [filePath, entries] of this.#map) {
+      for (const entry of entries) {
+        if (entry.timestamp < cutoff) {
+          entries.delete(entry);
+          removed++;
+        }
+      }
+      if (entries.size === 0) {
+        this.#map.delete(filePath);
+      }
+    }
+
+    return removed;
+  }
+
+  // ---- query ----------------------------------------------------------
+
+  /**
+   * Query the raw ConflictEntry set for a file path. Returns empty set
+   * when there are no entries (never mutated the file).
+   */
+  getEntriesFor(filePath: string): ReadonlySet<ConflictEntry> {
+    return this.#map.get(filePath) ?? new Set();
+  }
+
+  /**
+   * Get all conflict verdicts for a given file path — which other
+   * worktrees are touching it. Returns empty when only one worktree
+   * has entries (no actual conflict).
+   */
+  getConflictsFor(filePath: string): ConflictVerdict[] {
+    const entries = this.#map.get(filePath);
+    if (!entries || entries.size === 0) return [];
+
+    // Determine distinct worktree IDs. If only one, no conflict.
+    const worktreeIds = new Set<string>();
+    for (const e of entries) worktreeIds.add(e.worktreeId);
+    if (worktreeIds.size <= 1) return [];
+
+    // Use the first worktree as the "caller" so findConflicts excludes
+    // its entries and returns only entries from OTHER worktrees.
+    const caller = [...worktreeIds][0]!;
+    return findConflicts(
+      [filePath],
+      caller,
+      new Map(),
+      this.#toIndexData(),
+    );
+  }
+
+  /**
+   * Get conflicts for a set of file changes from a specific worktree.
+   * Delegates to the pure findConflicts function.
+   */
+  query(
+    changedFiles: string[],
+    worktreeId: string,
+    changedRanges: Map<string, { start: number; end: number }>,
+  ): ConflictVerdict[] {
+    return findConflicts(changedFiles, worktreeId, changedRanges, this.#toIndexData());
+  }
+
+  /**
+   * Snapshot the current map for testing/inspection.
+   */
+  snapshot(): Map<string, ReadonlySet<ConflictEntry>> {
+    return new Map(this.#map);
+  }
+
+  // ---- private --------------------------------------------------------
+
+  #toIndexData(): ReadonlyMap<string, ReadonlySet<ConflictEntry>> {
+    return this.#map as ReadonlyMap<string, ReadonlySet<ConflictEntry>>;
+  }
+}
+
+// Singleton — the whole BooCoder process shares one conflict index.
+export const conflictIndex = new ConflictIndex();

apps/coder/src/services/flow-runner-decisions.ts

@@ -33,11 +33,43 @@ export interface SchedulerState {
   readonly inFlight: ReadonlySet<string>;
   /** step ids pre-skipped at launch (band/when gating) — never given a row */
   readonly excluded: ReadonlySet<string>;
+  /** step ids that timed out (terminal — no retries remaining or not retriable) */
+  readonly timedOut: ReadonlySet<string>;
+  /**
+   * Per-batch running sets, populated by buildBatchState from the flow definition
+   * and the current inFlight set. Only read by getReadyInBatch; never mutated by
+   * decision functions (the caller maintains it across ticks).
+   */
+  readonly batchState?: Map<string, { running: Set<string>; maxConcurrent: number; joinRule: TriggerRule }>;
+  /**
+   * Per-switch-step routing results. Populated when a SWITCH step completes.
+   * Step ids in any result's `excluded` set are treated as excluded for the
+   * remainder of the run — they won't execute and won't block dependents.
+   */
+  readonly switchResults: ReadonlyMap<string, { chosenCase: string | null; excluded: ReadonlySet<string> }>;
 }
 
-/** A dependency is satisfied once it is done, skipped, or excluded. */
+/** A dependency is satisfied once it is done, skipped, excluded, or timed out. */
 function isSatisfied(state: SchedulerState, id: string): boolean {
-  return state.done.has(id) || state.skipped.has(id) || state.excluded.has(id);
+  const effectiveExcluded = getEffectiveExcluded(state);
+  return state.done.has(id) || state.skipped.has(id) || effectiveExcluded.has(id) || state.timedOut.has(id);
+}
+
+/**
+ * The union of the static `excluded` set and every switch result's excluded
+ * step ids. Steps excluded by a SWITCH evaluation act exactly like launch-time
+ * excluded steps: they never run and they don't block dependents.
+ */
+function getEffectiveExcluded(state: SchedulerState): ReadonlySet<string> {
+  // Fast path: no switch results → static excluded only.
+  if (state.switchResults.size === 0) return state.excluded;
+  const combined = new Set(state.excluded);
+  for (const result of state.switchResults.values()) {
+    for (const id of result.excluded) {
+      combined.add(id);
+    }
+  }
+  return combined;
 }
 
 /**
@@ -56,13 +88,14 @@ export function manifestSteps(flow: Flow, launchCtx: StepContext): Step[] {
  * Faithful to `conductor/flow.ts:27-36`. Pure.
  */
 export function readySteps(flow: Flow, state: SchedulerState): Step[] {
+  const effectiveExcluded = getEffectiveExcluded(state);
   return flow.steps.filter(
     (s) =>
       !state.done.has(s.id) &&
       !state.skipped.has(s.id) &&
       !state.inFlight.has(s.id) &&
-      !state.excluded.has(s.id) &&
+      !effectiveExcluded.has(s.id) &&
-      ((s.deps ?? []).length === 0 || evaluateTriggerRule(s.deps ?? [], state.done, state.skipped, state.excluded, s.trigger_rule)),
+      ((s.deps ?? []).length === 0 || evaluateTriggerRule(s.deps ?? [], state.done, state.skipped, effectiveExcluded, s.trigger_rule)),
   );
 }
 
@@ -102,6 +135,57 @@ export function isStuck(flow: Flow, state: SchedulerState): boolean {
   );
 }
 
+// ─── Batch parallelism (v2.8.22) ─────────────────────────────────────────────
+
+/**
+ * Build the batchState Map from the flow definition and the current inFlight set.
+ * Only steps with a `batch` field are tracked. Empty map when `flow.batchConfig`
+ * is absent or no steps belong to a batch. Pure — no IO.
+ */
+export function buildBatchState(
+  flow: Flow,
+  inFlight: ReadonlySet<string>,
+): Map<string, { running: Set<string>; maxConcurrent: number; joinRule: TriggerRule }> {
+  const result = new Map<string, { running: Set<string>; maxConcurrent: number; joinRule: TriggerRule }>();
+  if (!flow.batchConfig) return result;
+
+  // Collect every unique batch group referenced by the flow's steps.
+  const groups = new Set<string>();
+  for (const s of flow.steps) {
+    if (s.batch) groups.add(s.batch);
+  }
+
+  const { maxConcurrent, joinRule } = flow.batchConfig;
+  for (const batch of groups) {
+    const running = new Set<string>(
+      flow.steps.filter((s) => s.batch === batch && inFlight.has(s.id)).map((s) => s.id),
+    );
+    result.set(batch, { running, maxConcurrent, joinRule: joinRule ?? 'all_success' });
+  }
+  return result;
+}
+
+/**
+ * Gate a ready step list by batch parallelism limits. Steps without a `batch`
+ * field always pass through. Steps belonging to a batch are only included if
+ * that batch's currently-running count is below its `maxConcurrent` cap.
+ *
+ * This is ADDITIVE to the existing wave scheduler: pure dep-based readiness
+ * is computed first (readySteps), then this function applies the batch ceiling.
+ * Steps excluded here remain pending and will be picked up on the next tick
+ * when a running batch step completes.
+ */
+export function getReadyInBatch(ready: readonly Step[], state: SchedulerState, _flow: Flow): Step[] {
+  const batchState = state.batchState;
+  if (!batchState || batchState.size === 0) return [...ready];
+  return ready.filter((s) => {
+    if (!s.batch) return true;
+    const bs = batchState.get(s.batch);
+    if (!bs) return true;
+    return bs.running.size < bs.maxConcurrent;
+  });
+}
+
 // ─── Resume reconciliation (D-9) ─────────────────────────────────────────────
 
 /**
@@ -118,12 +202,29 @@ export function isStuck(flow: Flow, state: SchedulerState): boolean {
  * - 'mark-cancelled': task was cancelled before the callback ran; propagate so
  *                     advance() cancels the run.
  */
+/**
+ * True when the step definition allows retries on timeout.
+ * Pure — no IO.
+ */
+export function isRetriable(step: { maxRetries?: number }): boolean {
+  return (step.maxRetries ?? 0) > 0;
+}
+
+/**
+ * True when the step has retries remaining.
+ * Pure — no IO.
+ */
+export function shouldRetry(maxRetries: number | undefined | null, retryCount: number): boolean {
+  return retryCount < (maxRetries ?? 0);
+}
+
 export type ResumeAction =
   | 'keep'
   | 're-dispatch'
   | 'mark-done'
   | 'mark-failed'
-  | 'mark-cancelled';
+  | 'mark-cancelled'
+  | 'retry';
 
 /**
  * Decide what to do with ONE flow step during startup resume (D-9). Pure.
@@ -131,12 +232,20 @@ export type ResumeAction =
  * @param status     - flow_steps.status
  * @param taskId     - flow_steps.task_id (null for code steps or unstarted agent steps)
  * @param taskState  - tasks.state for taskId, or null if the task row is absent
+ * @param retryCount - flow_steps.retry_count (default 0)
+ * @param maxRetries - flow_steps.max_retries (null = no retry)
  */
 export function reconcileResumeStep(
   status: string,
   taskId: string | null,
   taskState: string | null,
+  retryCount?: number,
+  maxRetries?: number | null,
 ): ResumeAction {
+  if (status === 'timed_out') {
+    if (shouldRetry(maxRetries, retryCount ?? 0)) return 'retry';
+    return 'mark-failed';
+  }
   if (status !== 'running') return 'keep';
   // Running step: decide by its task's current state.
   if (!taskId || taskState === null) return 're-dispatch'; // task gone or never created
@@ -167,6 +276,60 @@ export function shouldFailOnMissingAgent(agent: string, modeId: string | null):
   return agent === 'qwen' && modeId === 'plan';
 }
 
+/**
+ * Evaluate a SWITCH step: iterate cases in declaration order and return the
+ * label of the first matching case plus every step id that belongs to a
+ * non-selected branch. When no case matches, the defaultBranch (if present)
+ * is the effective choice. If there is no default, all branch steps are
+ * excluded and the switch returns `chosenCase: null`.
+ *
+ * Pure — no IO. The caller adds the returned `excluded` ids to the scheduler
+ * state's switchResults so downstream decision functions see them as excluded.
+ */
+export function resolveSwitch(
+  step: Step,
+  ctx: StepContext,
+): { chosenCase: string | null; excluded: string[] } {
+  const cases = step.cases;
+  if (!cases || cases.length === 0) {
+    // Degenerate switch — nothing to evaluate.
+    return { chosenCase: null, excluded: [] };
+  }
+
+  // Evaluate conditions in order.
+  for (const c of cases) {
+    if (c.condition(ctx)) {
+      // This case matches — exclude all OTHER branches.
+      const excluded: string[] = [];
+      for (const other of cases) {
+        if (other.label !== c.label) {
+          excluded.push(...other.stepIds);
+        }
+      }
+      // The default branch is also excluded when a case matched.
+      if (step.defaultBranch) excluded.push(...step.defaultBranch);
+      return { chosenCase: c.label, excluded };
+    }
+  }
+
+  // No case matched — use default branch if present.
+  if (step.defaultBranch) {
+    // Default is the chosen branch: exclude all explicit case branches.
+    const excluded: string[] = [];
+    for (const c of cases) {
+      excluded.push(...c.stepIds);
+    }
+    return { chosenCase: null, excluded };
+  }
+
+  // No case matched and no default — exclude everything.
+  const excluded: string[] = [];
+  for (const c of cases) {
+    excluded.push(...c.stepIds);
+  }
+  return { chosenCase: null, excluded };
+}
+
 /**
  * Evaluate a trigger rule against dependency results.
  * - all_success: every dep must be done (not skipped/failed)
@@ -198,7 +361,7 @@ export function evaluateTriggerRule(
  * decision per step. Pure — no IO.
  */
 export function reconcileRun(
-  steps: ReadonlyArray<{ stepId: string; taskId: string | null; status: string }>,
+  steps: ReadonlyArray<{ stepId: string; taskId: string | null; status: string; retryCount?: number; maxRetries?: number | null }>,
   taskStates: ReadonlyMap<string, string>,
 ): StepResumeDecision[] {
   return steps.map((step) => ({
@@ -207,6 +370,8 @@ export function reconcileRun(
       step.status,
       step.taskId,
       step.taskId ? (taskStates.get(step.taskId) ?? null) : null,
+      step.retryCount,
+      step.maxRetries,
     ),
   }));
 }

apps/coder/src/services/flow-runner.ts

@@ -40,11 +40,14 @@ import { getFlow } from '../conductor/flows/index.js';
 import { loadPersona } from '../conductor/persona-loader.js';
 import type { Band, DispatchFn, Flow, FlowInput, Step, StepContext } from '../conductor/types.js';
 import {
+  buildBatchState,
+  getReadyInBatch,
   isRunComplete,
   manifestSteps,
   partitionReady,
   readySteps,
   reconcileRun,
+  resolveSwitch,
   type SchedulerState,
   type StepResumeDecision,
 } from './flow-runner-decisions.js';
@@ -95,11 +98,14 @@ interface Deps {
 
 interface FlowStepRow {
   step_id: string;
-  kind: 'agent' | 'code';
+  kind: 'agent' | 'code' | 'switch';
   agent: string | null;
   status: string;
   chat_id: string | null;
   output: string | null;
+  updated_at: string | null;
+  retry_count: number | null;
+  max_retries: number | null;
 }
 
 export function createFlowRunner(deps: Deps): FlowRunner {
@@ -263,7 +269,8 @@ export function createFlowRunner(deps: Deps): FlowRunner {
     const dispatch: DispatchFn = (agent, task) => dispatchSubAgent(run.project_id, model, agent, task);
 
     const rows = await sql<FlowStepRow[]>`
-      SELECT step_id, kind, agent, status, chat_id, output FROM flow_steps WHERE run_id = ${runId}
+      SELECT step_id, kind, agent, status, chat_id, output, updated_at, retry_count, max_retries
+      FROM flow_steps WHERE run_id = ${runId}
     `;
 
     // Re-derive the excluded set (band/when pre-skips) from the flow def + input —
@@ -275,6 +282,9 @@ export function createFlowRunner(deps: Deps): FlowRunner {
     const done = new Set<string>();
     const skipped = new Set<string>();
     const inFlight = new Set<string>();
+    const timedOut = new Set<string>();
+    /** Per-switch routing results — maps switch step id → resolved branch details */
+    const switchExcluded = new Map<string, { chosenCase: string | null; excluded: Set<string> }>();
     const results: Record<string, string> = {};
     for (const r of rows) {
       switch (r.status) {
@@ -288,6 +298,9 @@ export function createFlowRunner(deps: Deps): FlowRunner {
         case 'running':
           inFlight.add(r.step_id);
           break;
+        case 'timed_out':
+          timedOut.add(r.step_id);
+          break;
         case 'failed':
           // A failed worker makes the deterministic report untrustworthy — fail the
           // whole run (matches the Phase-1 CLI, which throws on a dispatch failure).
@@ -300,17 +313,79 @@ export function createFlowRunner(deps: Deps): FlowRunner {
       }
     }
 
+    // ─── Timeout detection ───────────────────────────────────────────────────────
+    // Check running steps. If a step has been 'running' longer than
+    // FLOW_STEP_TIMEOUT_MS, mark it timed_out or re-dispatch if retriable.
+    // Build a context here so the timeout retry path can re-dispatch the step.
+    const timeoutCtx = buildCtx(input, results, model, dispatch);
+    const timeoutMs = config.FLOW_STEP_TIMEOUT_MS;
+    const nowDate = new Date();
+    let detectedTimedOut = false;
+    for (const r of rows) {
+      if (r.status !== 'running') continue;
+      if (!r.updated_at) continue;
+      const elapsed = nowDate.getTime() - new Date(r.updated_at).getTime();
+      if (elapsed <= timeoutMs) continue;
+
+      // Step has exceeded the timeout
+      detectedTimedOut = true;
+      const retryCount = r.retry_count ?? 0;
+      const maxRetries = r.max_retries ?? 0;
+
+      if (maxRetries > 0 && retryCount < maxRetries) {
+        // Retriable: re-dispatch the step with an incremented retry_count
+        const step = flow.steps.find((s) => s.id === r.step_id);
+        if (!step || step.kind !== 'agent') {
+          // Non-agent steps can't be retried via dispatch
+          inFlight.delete(r.step_id);
+          await failRun(runId, flow, input, model,
+            `step '${r.step_id}' timed out (non-retriable kind)`, r.step_id);
+          return;
+        }
+        inFlight.delete(r.step_id);
+        await sql`
+          UPDATE flow_steps
+          SET retry_count = ${retryCount + 1}, updated_at = clock_timestamp()
+          WHERE run_id = ${runId} AND step_id = ${r.step_id} AND status = 'running'
+        `;
+        await dispatchAgentStep(runId, run.project_id, model, step, timeoutCtx);
+        inFlight.add(r.step_id);
+        log.warn({ runId, stepId: r.step_id, retry: retryCount + 1, maxRetries },
+          'flow-runner: step timed out, retrying');
+      } else {
+        // Not retriable — mark as timed_out, fail the run
+        inFlight.delete(r.step_id);
+        await sql`
+          UPDATE flow_steps SET status = 'timed_out', updated_at = clock_timestamp()
+          WHERE run_id = ${runId} AND step_id = ${r.step_id} AND status = 'running'
+        `;
+        timedOut.add(r.step_id);
+        publishStep(runId, r.step_id, 'timed_out');
+        await failRun(runId, flow, input, model,
+          `step '${r.step_id}' timed out`, r.step_id);
+        return;
+      }
+    }
+
+    // If we modified any steps, re-query so the state sets reflect the latest DB.
+    if (detectedTimedOut) {
+      // Continue with the in-memory state we already adjusted above (inFlight/timedOut
+      // were mutated directly). No re-query needed.
+    }
+
     // Drain ready skips + code steps (synchronous), re-evaluating after each batch,
     // then dispatch the full ready agent wave and wait for their terminal callbacks.
     for (;;) {
-      const state: SchedulerState = { done, skipped, inFlight, excluded };
+      // Build per-batch state from the current inFlight set for batch parallelism gating.
+      const batchState = buildBatchState(flow, inFlight);
+      const state: SchedulerState = { done, skipped, inFlight, excluded, timedOut, batchState, switchResults: switchExcluded };
 
       if (isRunComplete(flow, state)) {
         await finishRun(runId, flow, input, results, model, dispatch);
         return;
       }
 
-      const ready = readySteps(flow, state);
+      const ready = getReadyInBatch(readySteps(flow, state), state, flow);
       if (ready.length === 0) {
         if (inFlight.size > 0) return; // agents in flight will re-enter via the hook
         await failRun(runId, flow, input, model, 'unsatisfiable dependencies / cycle');
@@ -329,6 +404,31 @@ export function createFlowRunner(deps: Deps): FlowRunner {
         continue; // re-evaluate — a skip can settle a fan-in step's deps
       }
 
+      // SWITCH steps run synchronously — evaluate conditions, update the excluded
+      // set in SchedulerState, and mark themselves complete. Non-selected branch
+      // step ids are excluded from ever running.
+      const switchReady = toRun.filter((s) => s.kind === 'switch');
+      if (switchReady.length > 0) {
+        for (const s of switchReady) {
+          let result: { chosenCase: string | null; excluded: string[] };
+          try {
+            result = resolveSwitch(s, buildCtx(input, results, model, dispatch));
+          } catch (err) {
+            await failRun(runId, flow, input, model, `switch step '${s.id}' threw: ${errMsg(err)}`, s.id);
+            return;
+          }
+          switchExcluded.set(s.id, {
+            chosenCase: result.chosenCase,
+            excluded: new Set(result.excluded),
+          });
+          const outputText = result.chosenCase ? `branch:${result.chosenCase}` : '';
+          await markStep(runId, s.id, 'completed', outputText);
+          results[s.id] = outputText;
+          done.add(s.id);
+        }
+        continue; // re-evaluate — excluded steps may unblock dependents
+      }
+
       const codeReady = toRun.filter((s) => s.kind === 'code');
       if (codeReady.length > 0) {
         for (const s of codeReady) {
@@ -545,7 +645,7 @@ export function createFlowRunner(deps: Deps): FlowRunner {
   function publishStep(
     runId: string,
     stepId: string,
-    status: 'running' | 'completed' | 'failed' | 'skipped' | 'cancelled' | 'blocked',
+    status: 'running' | 'completed' | 'failed' | 'skipped' | 'cancelled' | 'blocked' | 'timed_out',
     extra?: { run_status?: 'running' | 'completed' | 'failed' | 'cancelled'; report?: string },
   ): void {
     publishUser({
@@ -683,6 +783,38 @@ export function createFlowRunner(deps: Deps): FlowRunner {
         log.info({ runId, stepId: step.step_id, taskId: task!.id }, 'flow-runner: step re-dispatched on resume');
         break;
       }
+
+      case 'retry': {
+        // Like re-dispatch but increments retry_count and sets status to 'running'.
+        if (!step.input) {
+          await sql`
+            UPDATE flow_steps
+            SET status = 'failed', error = 'retry: no stored prompt',
+                updated_at = clock_timestamp()
+            WHERE run_id = ${runId} AND step_id = ${step.step_id}
+          `;
+          break;
+        }
+        const chatIdR = step.chat_id;
+        const [chatR] = chatIdR
+          ? await sql<{ session_id: string }[]>`SELECT session_id FROM chats WHERE id = ${chatIdR}`
+          : [];
+        const sessionIdR = chatR?.session_id ?? null;
+        const [taskR] = await sql<{ id: string }[]>`
+          INSERT INTO tasks (project_id, input, agent, model, mode_id, session_id, chat_id)
+          VALUES (${projectId}, ${step.input}, 'qwen', ${model}, 'plan', ${sessionIdR}, ${chatIdR})
+          RETURNING id
+        `;
+        await sql`
+          UPDATE flow_steps
+          SET task_id = ${taskR!.id}, retry_count = retry_count + 1, status = 'running',
+              updated_at = clock_timestamp()
+          WHERE run_id = ${runId} AND step_id = ${step.step_id}
+        `;
+        log.info({ runId, stepId: step.step_id, taskId: taskR!.id },
+          'flow-runner: step retried on resume');
+        break;
+      }
     }
   }
 
@@ -697,7 +829,9 @@ export function createFlowRunner(deps: Deps): FlowRunner {
       status: string;
       chat_id: string | null;
       input: string | null;
-    }[]>`SELECT step_id, task_id, status, chat_id, input FROM flow_steps WHERE run_id = ${run.id}`;
+      retry_count: number | null;
+      max_retries: number | null;
+    }[]>`SELECT step_id, task_id, status, chat_id, input, retry_count, max_retries FROM flow_steps WHERE run_id = ${run.id}`;
 
     // Load task states for all referenced tasks in one query.
     const taskIds = rows.map((r) => r.task_id).filter((id): id is string => id !== null);
@@ -710,7 +844,13 @@ export function createFlowRunner(deps: Deps): FlowRunner {
     }
 
     const decisions = reconcileRun(
-      rows.map((r) => ({ stepId: r.step_id, taskId: r.task_id, status: r.status })),
+      rows.map((r) => ({
+        stepId: r.step_id,
+        taskId: r.task_id,
+        status: r.status,
+        retryCount: r.retry_count ?? undefined,
+        maxRetries: r.max_retries,
+      })),
       taskStates,
     );
 
@@ -752,13 +892,13 @@ export function createFlowRunner(deps: Deps): FlowRunner {
     // Mark all non-terminal steps cancelled and collect in-flight task_ids.
     const steps = await sql<{ step_id: string; task_id: string | null; kind: string }[]>`
       SELECT step_id, task_id, kind FROM flow_steps
-      WHERE run_id = ${runId} AND status NOT IN ('completed', 'failed', 'cancelled', 'skipped')
+      WHERE run_id = ${runId} AND status NOT IN ('completed', 'failed', 'cancelled', 'skipped', 'timed_out')
     `;
 
     if (steps.length > 0) {
       await sql`
         UPDATE flow_steps SET status = 'cancelled', updated_at = clock_timestamp()
-        WHERE run_id = ${runId} AND status NOT IN ('completed', 'failed', 'cancelled', 'skipped')
+        WHERE run_id = ${runId} AND status NOT IN ('completed', 'failed', 'cancelled', 'skipped', 'timed_out')
       `;
       for (const s of steps) {
         if (s.kind === 'agent') publishStep(runId, s.step_id, 'cancelled', { run_status: 'cancelled' });

apps/coder/src/services/paseo-client.ts

@@ -0,0 +1,341 @@
+/**
+ * v2.10 — PaseoClient: thin CLI-based client for the Paseo daemon.
+ *
+ * Paseo is a multi-agent hub daemon running at a configurable address
+ * (default Unix socket / localhost:6767). This client wraps the `paseo` CLI
+ * via child_process spawn for all operations (the daemon does not expose a
+ * separate REST API for write operations). Read operations (listAgents,
+ * getAgentStatus) use `paseo ls --json` / `paseo inspect --json`; write
+ * operations (import, archive, send) use the corresponding subcommands.
+ *
+ * Spec: openspec/changes/v2-10-paseo-integration/design.md.
+ */
+import { spawn } from 'node:child_process';
+import { once } from 'node:events';
+import { createInterface } from 'node:readline';
+
+// ─── Types ───────────────────────────────────────────────────────────────────
+
+/** Listing entry from `paseo ls --json`. Fields are lowercase. */
+export interface PaseoAgentListItem {
+  id: string;
+  shortId: string;
+  name: string;
+  provider: string;
+  status: string;
+  cwd?: string;
+  created?: string;
+  thinking?: string;
+}
+
+/** Detailed agent info from `paseo inspect --json`. Fields are PascalCase. */
+export interface PaseoAgentDetail {
+  Id: string;
+  Name: string;
+  Provider: string;
+  Model?: string;
+  Status: string;
+  Thinking?: string;
+  Archived: boolean;
+  ArchivedAt?: string | null;
+  Cwd?: string;
+  CreatedAt: string;
+  UpdatedAt: string;
+  Mode?: string;
+  AvailableModes?: Array<{ id: string; label: string }>;
+  Capabilities?: {
+    Streaming?: boolean;
+    Persistence?: boolean;
+    DynamicModes?: boolean;
+    McpServers?: boolean;
+  };
+  Labels?: Record<string, string>;
+  Worktree?: string | null;
+  ParentAgentId?: string | null;
+}
+
+/** Result of `paseo send --json`. */
+export interface PaseoSendResult {
+  /** The agent's textual response. */
+  text?: string;
+  /** Structured output if the agent produced any. */
+  output?: unknown;
+  /** Error message if the turn failed. */
+  error?: string;
+  /** True if the turn completed successfully. */
+  ok?: boolean;
+}
+
+export interface PaseoClientConfig {
+  /** Path to the paseo binary. Default: auto-resolved from PATH. */
+  paseoBin: string;
+  /**
+   * Explicit `--host <host>` value for CLI calls.
+   * Format: `host:port` or `tcp://host:port?ssl=true&password=secret`.
+   * Omit to use the CLI default (Unix socket, fallback localhost:6767).
+   */
+  cliHost?: string;
+}
+
+const DEFAULT_PASEO_BIN = 'paseo';
+
+// ─── Client ──────────────────────────────────────────────────────────────────
+
+export class PaseoClientError extends Error {
+  constructor(
+    message: string,
+    public readonly command: string,
+    public readonly exitCode: number | null,
+    public readonly stderr: string,
+  ) {
+    super(message);
+    this.name = 'PaseoClientError';
+  }
+}
+
+export class PaseoClient {
+  /** @internal visible for testing */
+  readonly bin: string;
+  private readonly hostArgs: string[];
+
+  constructor(config?: Partial<PaseoClientConfig>) {
+    this.bin = config?.paseoBin ?? DEFAULT_PASEO_BIN;
+    this.hostArgs = config?.cliHost ? ['--host', config.cliHost] : [];
+  }
+
+  // ─── Read operations (CLI `ls --json`, `inspect --json`) ──────────────────
+
+  /** List all non-archived agents. */
+  async listAgents(): Promise<PaseoAgentListItem[]> {
+    const raw = await this.runJson(['ls', '--json', ...this.hostArgs]);
+    return raw as PaseoAgentListItem[];
+  }
+
+  /** Get detailed status for a single agent by ID or prefix. */
+  async getAgentStatus(agentId: string): Promise<PaseoAgentDetail> {
+    const raw = await this.runJson(['inspect', '--json', agentId, ...this.hostArgs]);
+    return raw as PaseoAgentDetail;
+  }
+
+  /**
+   * Quick liveness check — runs `paseo ls --json --limit 1` and returns success.
+   * The daemon is healthy if the CLI exits 0.
+   */
+  async health(): Promise<{ status: string }> {
+    try {
+      await this.runCli(['ls', '--json', '--limit', '1', ...this.hostArgs]);
+      return { status: 'ok' };
+    } catch {
+      return { status: 'error' };
+    }
+  }
+
+  // ─── Write operations (CLI subcommands) ───────────────────────────────────
+
+  /**
+   * Import a provider session as a Paseo agent.
+   * Uses `paseo import <sessionId> --provider <provider> [--label k=v]`.
+   */
+  async importAgent(
+    sessionId: string,
+    provider: string,
+    labels?: Record<string, string>,
+  ): Promise<PaseoAgentDetail> {
+    const args: string[] = ['import', '--json', ...this.hostArgs];
+
+    if (provider) {
+      args.push('--provider', provider);
+    }
+    if (labels) {
+      for (const [k, v] of Object.entries(labels)) {
+        args.push('--label', `${k}=${v}`);
+      }
+    }
+    args.push(sessionId);
+
+    const raw = await this.runJson(args);
+    return raw as PaseoAgentDetail;
+  }
+
+  /** Archive (soft-delete) a Paseo agent by ID or prefix. */
+  async archiveAgent(agentId: string): Promise<void> {
+    await this.runCli(['archive', '--json', ...this.hostArgs, agentId]);
+  }
+
+  /**
+   * Send a prompt to an existing agent.
+   *
+   * By default waits for the agent to complete the turn (streams text events
+   * via the optional `onEvent` callback) and returns the structured result.
+   * Pass `noWait: true` to fire-and-forget.
+   */
+  async sendPrompt(
+    agentId: string,
+    prompt: string,
+    options?: {
+      noWait?: boolean;
+      onEvent?: (event: { type: 'text' | 'reasoning'; text: string }) => void;
+      signal?: AbortSignal;
+    },
+  ): Promise<PaseoSendResult> {
+    const args: string[] = ['send', '--json', ...this.hostArgs];
+
+    if (options?.noWait) {
+      args.push('--no-wait');
+    }
+
+    args.push(agentId, prompt);
+
+    // With --json and no --no-wait, the output is JSON after completion.
+    // For streaming, we read stderr without --json for real-time text.
+    const raw = await this.runCli(args, options?.signal);
+    try {
+      return JSON.parse(raw) as PaseoSendResult;
+    } catch {
+      return { text: raw, ok: true };
+    }
+  }
+
+  /**
+   * Stream-send: runs `paseo send` WITHOUT `--json`, forward text/reasoning
+   * lines to onEvent in real time. Use when the caller wants to stream agent
+   * output as it arrives rather than wait for the full JSON result.
+   */
+  async streamSend(
+    agentId: string,
+    prompt: string,
+    onEvent: (event: { type: 'text' | 'reasoning'; text: string }) => void,
+    signal?: AbortSignal,
+  ): Promise<PaseoSendResult> {
+    return new Promise<PaseoSendResult>((resolve, reject) => {
+      const args = ['send', ...this.hostArgs, agentId, prompt];
+
+      const child = spawn(this.bin, args, {
+        stdio: ['ignore', 'pipe', 'pipe'],
+        signal,
+      });
+
+      let stdout = '';
+      let stderr = '';
+
+      if (child.stdout) {
+        const rl = createInterface({ input: child.stdout });
+        rl.on('line', (line: string) => {
+          stdout += line + '\n';
+          // Forward as text event for real-time display
+          onEvent({ type: 'text', text: line + '\n' });
+        });
+      }
+
+      if (child.stderr) {
+        child.stderr.on('data', (chunk: Buffer) => {
+          stderr += chunk.toString();
+        });
+      }
+
+      once(child, 'close').then((raw) => {
+        const exitCode = (raw[0] as number | null) ?? 0;
+        if (exitCode !== 0) {
+          reject(
+            new PaseoClientError(
+              `paseo send failed (exit ${exitCode}): ${stderr.trim()}`,
+              'send',
+              exitCode,
+              stderr,
+            ),
+          );
+          return;
+        }
+        resolve({ text: stdout, ok: true });
+      });
+
+      child.on('error', reject);
+    });
+  }
+
+  /** Interrupt/stop a running agent. */
+  async stopAgent(agentId: string): Promise<void> {
+    await this.runCli(['stop', ...this.hostArgs, agentId]);
+  }
+
+  // ─── Private helpers ───────────────────────────────────────────────────────
+
+  /**
+   * Run a CLI command and return stdout as a string.
+   * Throws PaseoClientError on non-zero exit.
+   */
+  private async runCli(
+    args: string[],
+    signal?: AbortSignal,
+  ): Promise<string> {
+    return new Promise<string>((resolve, reject) => {
+      const child = spawn(this.bin, args, {
+        stdio: ['ignore', 'pipe', 'pipe'],
+        signal,
+      });
+
+      let stdout = '';
+      let stderr = '';
+
+      if (child.stdout) {
+        child.stdout.on('data', (chunk: Buffer) => {
+          stdout += chunk.toString();
+        });
+      }
+
+      if (child.stderr) {
+        child.stderr.on('data', (chunk: Buffer) => {
+          stderr += chunk.toString();
+        });
+      }
+
+      child.on('error', (err: Error) => {
+        // If signal aborted, treat as cancellation not error
+        if (signal?.aborted) {
+          resolve('');
+          return;
+        }
+        reject(err);
+      });
+
+      once(child, 'close').then((raw) => {
+        const exitCode = (raw[0] as number | null) ?? 0;
+        if (signal?.aborted) {
+          resolve('');
+          return;
+        }
+        if (exitCode !== 0) {
+          const msg = stderr.trim() || `exit code ${exitCode}`;
+          reject(
+            new PaseoClientError(
+              `paseo ${args[0] ?? '?'} failed: ${msg}`,
+              args[0] ?? '?',
+              exitCode,
+              stderr,
+            ),
+          );
+          return;
+        }
+        resolve(stdout);
+      });
+    });
+  }
+
+  /**
+   * Run a CLI command and parse stdout as JSON.
+   * Throws PaseoClientError on non-zero exit or parse failure.
+   */
+  private async runJson(args: string[]): Promise<unknown> {
+    const stdout = await this.runCli(args);
+    try {
+      return JSON.parse(stdout);
+    } catch (err) {
+      throw new PaseoClientError(
+        `paseo ${args[0] ?? '?'} returned invalid JSON: ${(stdout || '<empty>').slice(0, 200)}`,
+        args[0] ?? '?',
+        0,
+        stdout,
+      );
+    }
+  }
+}

apps/coder/src/services/pending_changes.ts

@@ -4,6 +4,8 @@ import { randomBytes } from 'node:crypto';
 import type { Sql } from '../db.js';
 import { resolveWritePath } from './write_guard.js';
 import { locateMatch } from './fuzzy-match.js';
+import { conflictIndex } from './conflict-index.js';
+import { findConflicts } from './collision-detector.js';
 
 /**
  * Write a file atomically: stage to a sibling temp file, then rename over the
@@ -170,6 +172,10 @@ export async function queueEdit(
     VALUES (${sessionId}, ${taskId}, ${resolved}, 'edit', ${diff}, ${agent})
     RETURNING *
   `;
+
+  // Register in the conflict index so concurrent worktrees see this edit.
+  conflictIndex.registerChange(resolved, sessionId, agent ?? 'unknown');
+
   return row!;
 }
 
@@ -216,6 +222,9 @@ export async function queueCreate(
     VALUES (${sessionId}, ${taskId}, ${resolved}, 'create', ${content}, ${agent})
     RETURNING *
   `;
+
+  conflictIndex.registerChange(resolved, sessionId, agent ?? 'unknown');
+
   return row!;
 }
 
@@ -238,6 +247,9 @@ export async function queueDelete(
     VALUES (${sessionId}, ${taskId}, ${resolved}, 'delete', '', ${agent})
     RETURNING *
   `;
+
+  conflictIndex.registerChange(resolved, sessionId, agent ?? 'unknown');
+
   return row!;
 }
 
@@ -260,6 +272,23 @@ export async function applyOne(
       // Re-validate path in case projectRoot has shifted
       resolveWritePath(projectRoot, change.file_path);
 
+      // Advisory collision check: log a warning if another worktree has pending
+      // edits to this file. Does NOT block the write — same non-blocking pattern
+      // as the edit guards (validateEditResult, checkDroppedImports).
+      {
+        const conflicts = conflictIndex.query(
+          [change.file_path],
+          change.session_id, // sessionId doubles as worktree identifier
+          new Map(),
+        );
+        for (const v of conflicts) {
+          console.log(
+            `[collision] ${v.filePath} — conflict with worktrees [${v.worktrees.join(', ')}] ` +
+            `agents [${v.agents.join(', ')}] severity=${v.severity}`,
+          );
+        }
+      }
+
       switch (change.operation) {
         case 'create': {
           await mkdir(dirname(change.file_path), { recursive: true });

apps/server/src/index.ts

@@ -18,11 +18,14 @@ import { registerCoderProxy } from './routes/coder-proxy.js';
 import { registerModelRoutes } from './routes/models.js';
 import { registerAgentRoutes } from './routes/agents.js';
 import { registerSkillsRoutes } from './routes/skills.js';
+import { registerTraceRoutes } from './routes/traces.js';
 import { registerToolsRoutes } from './routes/tools.js';
 import { registerAnalyticsRoutes } from './routes/analytics.js';
+
 import { registerInferenceSettingsRoutes } from './routes/inference-settings.js';
-import { createInferenceRunner } from './services/inference/index.js';
+import { createInferenceRunner, runInferenceWithModel } from './services/inference/index.js';
 import { createBroker } from './services/broker.js';
+import { setBackgroundInferenceEnqueuer } from './services/background-task.js';
 import { listSkills } from './services/skills.js';
 import * as compaction from './services/compaction.js';
 import { configureModelContext } from './services/model-context.js';
@@ -123,7 +126,35 @@ async function main() {
   registerModelRoutes(app, config);
   registerAgentRoutes(app, sql);
   registerSidebarRoutes(app, sql);
-  registerChatRoutes(app, sql, broker);
+  registerChatRoutes(app, sql, broker, config, {
+    enqueueCompare: (sessionId, chatId, assistantMessageId, modelOverride, compareGroupId) => {
+      // Reuse the inference runner's context pattern for compare mode.
+      // Each compare run gets its own AbortController; cancellation keyed by
+      // chatId (cancels ALL parallel runs in that compare group).
+      const compareCtx: import('./services/inference/types.js').InferenceContext = {
+        sql,
+        config,
+        log: app.log,
+        publish: (sid, frame) => {
+          broker.publishFrame(sid, frame as unknown as import('@boocode/contracts/ws-frames').WsFrame);
+        },
+        publishUser: (frame) => {
+          broker.publishUserFrame('default', frame as unknown as import('@boocode/contracts/ws-frames').WsFrame);
+        },
+        broker,
+        hooks: hasHooks ? hookRunner : undefined,
+      };
+      compareCtx.publishUser({ type: 'chat_status', chat_id: chatId, status: 'streaming', at: new Date().toISOString() });
+      void runInferenceWithModel(compareCtx, sessionId, chatId, assistantMessageId, modelOverride, compareGroupId).catch(
+        (err: Error) => app.log.error({ err, chatId, modelOverride }, 'compare inference failed'),
+      );
+    },
+    cancelInference: async (_sessionId, chatId) => {
+      return inference.cancel(_sessionId, chatId);
+    },
+    hasActiveInference: (chatId) => inference.hasActive(chatId),
+  });
+  registerTraceRoutes(app, sql);
   registerToolsRoutes(app, sql);
   registerAnalyticsRoutes(app, sql);
   registerInferenceSettingsRoutes(app);
@@ -163,6 +194,13 @@ async function main() {
       broker.publishUserFrame(user, frame as unknown as import('@boocode/contracts/ws-frames').WsFrame);
     }
   );
+  // v2.x: wire the background subagent task system to the inference runner.
+  // Tools (spawn_subagent) dispatch fire-and-forget inference via this
+  // module-level reference — no import cycle through the tool registry.
+  setBackgroundInferenceEnqueuer((sessionId, chatId, assistantId, user) => {
+    inference.enqueue(sessionId, chatId, assistantId, user);
+  });
+
   registerMessageRoutes(app, sql, config, broker, {
     enqueueInference: (sessionId, chatId, assistantId, user) => {
       inference.enqueue(sessionId, chatId, assistantId, user);

apps/server/src/routes/traces.ts

@@ -0,0 +1,38 @@
+import type { FastifyInstance } from 'fastify';
+import type { Sql } from '../db.js';
+import type { ToolTrace } from '../services/tool-traces.js';
+
+export function registerTraceRoutes(app: FastifyInstance, sql: Sql): void {
+  app.get<{ Params: { id: string }; Querystring: { limit?: string; offset?: string } }>(
+    '/api/chats/:id/traces',
+    async (req, reply) => {
+      const chat = await sql`SELECT id FROM chats WHERE id = ${req.params.id}`;
+      if (chat.length === 0) {
+        reply.code(404);
+        return { error: 'chat not found' };
+      }
+
+      const limit = Math.min(Math.max(Number(req.query.limit) || 50, 1), 200);
+      const offset = Math.max(Number(req.query.offset) || 0, 0);
+
+      const rows = await sql<ToolTrace[]>`
+        SELECT * FROM tool_traces
+        WHERE chat_id = ${req.params.id}
+        ORDER BY started_at ASC
+        LIMIT ${limit}
+        OFFSET ${offset}
+      `;
+
+      const [countRow] = await sql<{ count: number }[]>`
+        SELECT count(*)::int AS count FROM tool_traces WHERE chat_id = ${req.params.id}
+      `;
+
+      return {
+        data: rows,
+        total: countRow?.count ?? 0,
+        limit,
+        offset,
+      };
+    },
+  );
+}

apps/server/src/routes/ws.ts

@@ -3,6 +3,7 @@ import type { Sql } from '../db.js';
 import type { Broker } from '../services/broker.js';
 import type { Message } from '../types/api.js';
 import { MESSAGE_COLUMNS } from '../services/message-columns.js';
+import { loadAgentSnapshot } from '../services/session-snapshots.js';
 
 export function registerWebSocket(
   app: FastifyInstance,
@@ -33,6 +34,24 @@ export function registerWebSocket(
       `;
       socket.send(JSON.stringify({ type: 'snapshot', messages }));
 
+      // v2.7.x: on reconnect, restore agent snapshot state so the frontend
+      // knows there's an ongoing agent turn. Best-effort per chat; most
+      // sessions won't have any snapshots.
+      const chats = await sql<{ id: string }[]>`SELECT id FROM chats WHERE session_id = ${sessionId}`;
+      for (const chat of chats) {
+        const agentSnapshot = await loadAgentSnapshot(sql, chat.id).catch(() => null);
+        if (agentSnapshot) {
+          socket.send(JSON.stringify({
+            type: 'agent_snapshot',
+            chat_id: chat.id,
+            agent: agentSnapshot.agent,
+            model: agentSnapshot.model,
+            mode: agentSnapshot.mode,
+            turn_number: agentSnapshot.turn_number,
+          }));
+        }
+      }
+
       const unsubscribe = broker.subscribe(sessionId, (frame) => {
         if (socket.readyState !== socket.OPEN) return;
         try {

apps/server/src/schema.sql

@@ -32,11 +32,18 @@ CREATE TABLE IF NOT EXISTS messages (
   content TEXT NOT NULL DEFAULT '',
   status TEXT NOT NULL DEFAULT 'complete',
   last_seq INT NOT NULL DEFAULT 0,
+  cache_tokens INTEGER,
+  reasoning_tokens INTEGER,
   created_at TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp()
 );
 
 CREATE INDEX IF NOT EXISTS idx_messages_session ON messages(session_id, created_at);
 
+-- vDeepSeek: add cache/reasoning token columns early so messages_with_parts
+-- view (defined below) can reference them. IF NOT EXISTS guards re-runs.
+ALTER TABLE messages ADD COLUMN IF NOT EXISTS cache_tokens INTEGER;
+ALTER TABLE messages ADD COLUMN IF NOT EXISTS reasoning_tokens INTEGER;
+
 -- v1.13.0: granular message parts table. v1.13.20: legacy tool_calls/
 -- tool_results columns dropped; message_parts is now the sole source of
 -- truth for tool calls, tool results, and reasoning. ON DELETE CASCADE
@@ -204,8 +211,6 @@ ALTER TABLE messages ADD COLUMN IF NOT EXISTS ctx_used INTEGER;
 ALTER TABLE messages ADD COLUMN IF NOT EXISTS ctx_max INTEGER;
 ALTER TABLE messages ADD COLUMN IF NOT EXISTS started_at TIMESTAMPTZ;
 ALTER TABLE messages ADD COLUMN IF NOT EXISTS finished_at TIMESTAMPTZ;
-ALTER TABLE messages ADD COLUMN IF NOT EXISTS cache_tokens INTEGER;
-ALTER TABLE messages ADD COLUMN IF NOT EXISTS reasoning_tokens INTEGER;
 
 ALTER TABLE sessions ADD COLUMN IF NOT EXISTS updated_at TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp();
 
@@ -409,3 +414,55 @@ END $$;
 
 -- Remove the v2.0.5 arena_id column (replaced by the new Arena feature).
 ALTER TABLE tasks DROP COLUMN IF EXISTS arena_id;
+
+-- v2.x-tool-traces: per-call tool execution records for observability.
+CREATE TABLE IF NOT EXISTS tool_traces (
+  id               UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  session_id       UUID NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
+  chat_id          UUID NOT NULL REFERENCES chats(id) ON DELETE CASCADE,
+  message_id       UUID REFERENCES messages(id) ON DELETE SET NULL,
+  turn_number      INTEGER NOT NULL,
+  tool_name        TEXT NOT NULL,
+  tool_input       JSONB NOT NULL,
+  tool_output      TEXT,
+  started_at       TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
+  finished_at      TIMESTAMPTZ,
+  latency_ms       INTEGER,
+  tokens_used      INTEGER,
+  cache_tokens     INTEGER,
+  reasoning_tokens INTEGER,
+  error            TEXT,
+  outcome          TEXT,
+  created_at       TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp()
+);
+
+CREATE INDEX IF NOT EXISTS idx_tool_traces_chat ON tool_traces(chat_id, created_at);
+
+-- v2.x-tool-traces: active tool call state for in-flight instrumentation.
+CREATE TABLE IF NOT EXISTS tool_trace_states (
+  id               UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  session_id       UUID NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
+  chat_id          UUID NOT NULL REFERENCES chats(id) ON DELETE CASCADE,
+  message_id       UUID REFERENCES messages(id) ON DELETE SET NULL,
+  turn_number      INTEGER NOT NULL,
+  tool_name        TEXT NOT NULL,
+  tool_input       JSONB NOT NULL,
+  started_at       TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp()
+);
+
+-- agent_snapshots: persistent agent session state for cross-refresh resume.
+CREATE TABLE IF NOT EXISTS agent_snapshots (
+  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+  session_id UUID NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
+  chat_id UUID NOT NULL REFERENCES chats(id) ON DELETE CASCADE,
+  model TEXT NOT NULL,
+  agent TEXT,
+  mode TEXT,
+  turn_number INTEGER NOT NULL DEFAULT 0,
+  messages JSONB NOT NULL DEFAULT '[]'::jsonb,
+  tool_states JSONB NOT NULL DEFAULT '[]'::jsonb,
+  created_at TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
+  updated_at TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp()
+);
+CREATE INDEX IF NOT EXISTS idx_agent_snapshots_chat ON agent_snapshots(chat_id);
+CREATE UNIQUE INDEX IF NOT EXISTS idx_agent_snapshots_chat_unique ON agent_snapshots(chat_id);

apps/server/src/services/background-task.ts

@@ -0,0 +1,260 @@
+// v2.x: Background subagent task service.
+// Creates and tracks background tasks that run as independent inference
+// sessions. The spawner creates a session+chat, inserts messages, and
+// dispatches inference asynchronously. Callers poll status and retrieve
+// results via the companion tools (background-subagent-tools.ts).
+//
+// Module-level inference enqueuer: set at server startup so tools can
+// dispatch background inference without importing the runner directly.
+
+import type { Sql } from '../db.js';
+import type { FastifyBaseLogger } from 'fastify';
+
+export interface BackgroundTask {
+  id: string;
+  session_id: string;
+  chat_id: string;
+  agent: string | null;
+  model: string;
+  input: string;
+  status: 'pending' | 'running' | 'completed' | 'failed' | 'cancelled';
+  output_summary: string | null;
+  created_at: string;
+  finished_at: string | null;
+}
+
+// Module-level reference to the inference enqueuer, set at server startup.
+let _enqueueInference:
+  | ((sessionId: string, chatId: string, assistantMessageId: string, user: string) => void)
+  | null = null;
+
+export function setBackgroundInferenceEnqueuer(
+  enqueue: (
+    sessionId: string,
+    chatId: string,
+    assistantMessageId: string,
+    user: string,
+  ) => void,
+): void {
+  _enqueueInference = enqueue;
+}
+
+function mapTaskState(state: string): BackgroundTask['status'] {
+  switch (state) {
+    case 'pending':
+      return 'pending';
+    case 'running':
+      return 'running';
+    case 'completed':
+      return 'completed';
+    case 'failed':
+      return 'failed';
+    case 'blocked':
+      return 'pending'; // blocked is internal — surface as pending
+    case 'cancelled':
+      return 'cancelled';
+    default:
+      return 'pending';
+  }
+}
+
+// Spawn a background subagent task: create session + chat + messages + tasks
+// row, then fire-and-forget the inference. Returns immediately with the task
+// metadata — inference runs asynchronously.
+export async function spawnBackgroundTask(
+  sql: Sql,
+  log: FastifyBaseLogger,
+  projectId: string,
+  input: string,
+  model: string,
+  agent?: string,
+  label?: string,
+): Promise<BackgroundTask> {
+  const sessionName =
+    label != null && label.length > 0
+      ? `Subagent: ${label}`
+      : `Background: ${input.slice(0, 50)}${input.length > 50 ? '...' : ''}`;
+
+  const result = await sql.begin(async (tx) => {
+    // 1. Create session for the background task
+    const [sess] = await tx<{ id: string }[]>`
+      INSERT INTO sessions (project_id, name, model, system_prompt)
+      VALUES (${projectId}, ${sessionName}, ${model}, '')
+      RETURNING id
+    `;
+    const sessionId = sess!.id;
+
+    // 2. Create chat in that session
+    const [ch] = await tx<{ id: string }[]>`
+      INSERT INTO chats (session_id, name, status)
+      VALUES (${sessionId}, ${label ?? null}, 'open')
+      RETURNING id
+    `;
+    const chatId = ch!.id;
+
+    // 3. Insert user message with the task input
+    await tx`
+      INSERT INTO messages (session_id, chat_id, role, content, status, created_at)
+      VALUES (${sessionId}, ${chatId}, 'user', ${input}, 'complete', clock_timestamp())
+    `;
+
+    // 4. Insert streaming assistant message (inference fills it)
+    const [assistantRow] = await tx<{ id: string }[]>`
+      INSERT INTO messages (session_id, chat_id, role, content, status, created_at)
+      VALUES (${sessionId}, ${chatId}, 'assistant', '', 'streaming', clock_timestamp())
+      RETURNING id
+    `;
+    const assistantMessageId = assistantRow!.id;
+
+    // 5. Insert tasks row for tracking
+    const [task] = await tx<{ id: string; created_at: string }[]>`
+      INSERT INTO tasks (project_id, session_id, state, input, agent, model)
+      VALUES (${projectId}, ${sessionId}, 'running', ${input}, ${agent ?? null}, ${model})
+      RETURNING id, created_at
+    `;
+
+    return { sessionId, chatId, assistantMessageId, task: task! };
+  });
+
+  // After the transaction commits, fire-and-forget inference dispatch.
+  if (_enqueueInference) {
+    try {
+      _enqueueInference(result.sessionId, result.chatId, result.assistantMessageId, 'default');
+    } catch (err) {
+      log.warn(
+        { err, taskId: result.task.id },
+        'background inference enqueue failed',
+      );
+    }
+  }
+
+  log.info(
+    {
+      taskId: result.task.id,
+      sessionId: result.sessionId,
+      chatId: result.chatId,
+      model,
+      agent,
+    },
+    'spawned background subagent task',
+  );
+
+  return {
+    id: result.task.id,
+    session_id: result.sessionId,
+    chat_id: result.chatId,
+    agent: agent ?? null,
+    model,
+    input,
+    status: 'running',
+    output_summary: null,
+    created_at: result.task.created_at,
+    finished_at: null,
+  };
+}
+
+// Look up a background task by its tasks.id. Includes the status from the
+// tasks table and the chat_id from the linked chat.
+export async function getBackgroundTaskStatus(
+  sql: Sql,
+  taskId: string,
+): Promise<BackgroundTask | null> {
+  const rows = await sql<
+    {
+      id: string;
+      session_id: string;
+      state: string;
+      input: string;
+      agent: string | null;
+      model: string | null;
+      output_summary: string | null;
+      created_at: string;
+      ended_at: string | null;
+    }[]
+  >`
+    SELECT id, session_id, state, input, agent, model, output_summary, created_at, ended_at
+    FROM tasks
+    WHERE id = ${taskId}
+  `;
+  if (rows.length === 0) return null;
+  const r = rows[0]!;
+
+  // Find the chat_id from the session (background sessions have exactly one chat).
+  const chatRows = await sql<{ id: string }[]>`
+    SELECT id FROM chats WHERE session_id = ${r.session_id} LIMIT 2
+  `;
+
+  return {
+    id: r.id,
+    session_id: r.session_id,
+    chat_id: chatRows[0]?.id ?? '',
+    agent: r.agent,
+    model: r.model ?? '',
+    input: r.input,
+    status: mapTaskState(r.state),
+    output_summary: r.output_summary,
+    created_at: r.created_at,
+    finished_at: r.ended_at,
+  };
+}
+
+// Retrieve the full output and token usage from a completed background task.
+// Returns null if the task has no completed assistant message.
+export async function getBackgroundTaskResult(
+  sql: Sql,
+  taskId: string,
+  chatId: string,
+): Promise<{
+  output: string;
+  token_usage: { prompt: number; completion: number } | null;
+} | null> {
+  // Verify the task exists and chatId belongs to it.
+  const taskRows = await sql<{ session_id: string }[]>`
+    SELECT session_id FROM tasks WHERE id = ${taskId}
+  `;
+  if (taskRows.length === 0) return null;
+
+  // Read the last complete assistant message (the one with content).
+  const msgRows = await sql<
+    {
+      content: string;
+      tokens_used: number | null;
+      ctx_used: number | null;
+    }[]
+  >`
+    SELECT content, tokens_used, ctx_used
+    FROM messages
+    WHERE chat_id = ${chatId}
+      AND role = 'assistant'
+      AND status = 'complete'
+      AND content <> ''
+    ORDER BY created_at DESC
+    LIMIT 1
+  `;
+  if (msgRows.length === 0) return null;
+
+  const m = msgRows[0]!;
+  return {
+    output: m.content,
+    token_usage:
+      m.tokens_used != null || m.ctx_used != null
+        ? { prompt: m.ctx_used ?? 0, completion: m.tokens_used ?? 0 }
+        : null,
+  };
+}
+
+// Cancel a pending or running background task. Returns true if a row was
+// actually updated (the task existed and was in a cancellable state).
+export async function cancelBackgroundTask(
+  sql: Sql,
+  taskId: string,
+): Promise<boolean> {
+  const rows = await sql<{ id: string }[]>`
+    UPDATE tasks
+    SET state = 'cancelled', ended_at = clock_timestamp()
+    WHERE id = ${taskId}
+      AND state IN ('pending', 'running')
+    RETURNING id
+  `;
+  return rows.length > 0;
+}

apps/server/src/services/codecontext_client.ts

@@ -1,3 +1,10 @@
+// DEPRECATED (Phase 4, Domain 2, v2.8.14): This HTTP client routes through
+// the Go codecontext sidecar (http://codecontext:8080). Superseded by the
+// boocontext MCP server. New callers should use boocontext MCP tool wrappers
+// directly. Keep this file for backward compatibility — the 16 existing
+// codecontext tool wrappers (under tools/codecontext/) still call through
+// callCodecontext(). Remove after full migration.
+//
 // v1.12 Track B.2: shared HTTP client for the codecontext sidecar. The 8
 // per-tool wrappers under tools/codecontext/ all funnel through callCodecontext
 // — they're thin adapters that supply toolName + args + projectPath. The
@@ -19,6 +26,7 @@
 import { access, copyFile, realpath } from 'node:fs/promises';
 import { isAbsolute, join, resolve, sep } from 'node:path';
 import { truncateIfNeeded } from './truncate.js';
+import { callBoocontext } from './boocontext_client.js';
 
 // v1.13.12 fix: codecontext crashes on empty source files (upstream issue #37)
 // when it can't ignore them. The .codecontextignore.template ships with the
@@ -112,6 +120,16 @@ export async function callCodecontext(
   req: CodecontextRequest,
   fetcher: typeof fetch = fetch,
 ): Promise<CodecontextResponse> {
+  // Phase 4: try boocontext MCP first. Falls back to the HTTP sidecar if the
+  // MCP server is not available or the tool doesn't exist there.
+  try {
+    return await callBoocontext({ toolName: req.toolName, args: req.args });
+  } catch (err) {
+    console.warn(
+      `[codecontext_client] boocontext MCP unavailable for "${req.toolName}", falling back to HTTP sidecar: ${err instanceof Error ? err.message : String(err)}`,
+    );
+  }
+
   // Step 1: realpath the project root, then realpath the requested target_dir
   // (defaulting to projectPath when the caller didn't pass one — the 12 wrappers
   // never pass target_dir; tests can override). A non-existent target_dir

apps/server/src/services/inference/compute-diff.ts

@@ -0,0 +1,132 @@
+/**
+ * Compact unified-diff generator for write-tool results.
+ *
+ * Produces a minimal unified diff string (---/+++ header + +/- lines) from
+ * old/new text pairs so the frontend can render an inline diff snippet
+ * without pulling in a full diff library.
+ */
+
+// Write-tool names that can produce file diffs.
+export const WRITE_TOOL_NAMES = new Set([
+  'edit_file',
+  'create_file',
+  'delete_file',
+  'apply_pending',
+]);
+
+/**
+ * Compute a compact unified diff from old → new text.
+ *
+ * @param oldStr  The original text (empty for creates)
+ * @param newStr  The replacement text (empty for deletes)
+ * @param filePath  Display path for the file header
+ * @returns A unified-diff string, or empty string if old === new
+ */
+export function computeDiff(oldStr: string, newStr: string, filePath: string): string {
+  if (oldStr === newStr) return '';
+
+  const oldLines = oldStr.split('\n');
+  const newLines = newStr.split('\n');
+
+  // For empty old → new file (create), show all lines as additions
+  if (oldStr.length === 0 && newStr.length > 0) {
+    const header = `--- /dev/null\n+++ b/${filePath}\n`;
+    const body = newLines.map((line) => `+${line}`).join('\n');
+    return header + body;
+  }
+
+  // For old → empty (delete), show all lines as removals
+  if (newStr.length === 0 && oldStr.length > 0) {
+    const header = `--- a/${filePath}\n+++ /dev/null\n`;
+    const body = oldLines.map((line) => `-${line}`).join('\n');
+    return header + body;
+  }
+
+  // Simple line-by-line diff for edit: collect changed lines with context.
+  // Uses a straightforward algorithm: find the first differing line and the
+  // last differing line, then output the block with +/- markers.
+  const header = `--- a/${filePath}\n+++ b/${filePath}\n`;
+
+  const maxLen = Math.max(oldLines.length, newLines.length);
+  let firstDiff = -1;
+  let lastDiff = -1;
+
+  for (let i = 0; i < maxLen; i++) {
+    const a = i < oldLines.length ? oldLines[i] : undefined;
+    const b = i < newLines.length ? newLines[i] : undefined;
+    if (a !== b) {
+      if (firstDiff === -1) firstDiff = i;
+      lastDiff = i;
+    }
+  }
+
+  if (firstDiff === -1) return '';
+
+  // Add context lines around the changed block (up to 2 lines each side)
+  const contextBefore = 2;
+  const contextAfter = 2;
+  const start = Math.max(0, firstDiff - contextBefore);
+  const end = Math.min(maxLen - 1, lastDiff + contextAfter);
+
+  // Build the unified diff hunk
+  const hunkLines: string[] = [];
+  const hunkOldStart = start + 1; // 1-indexed
+  const hunkNewStart = start + 1;
+  const hunkOldLen = end - start + 1;
+  const hunkNewLen = end - start + 1;
+
+  for (let i = start; i <= end; i++) {
+    const oldLine = i < oldLines.length ? oldLines[i] : undefined;
+    const newLine = i < newLines.length ? newLines[i] : undefined;
+
+    if (oldLine === newLine) {
+      hunkLines.push(` ${oldLine ?? ''}`);
+    } else {
+      if (oldLine !== undefined) {
+        hunkLines.push(`-${oldLine}`);
+      }
+      if (newLine !== undefined) {
+        hunkLines.push(`+${newLine}`);
+      }
+    }
+  }
+
+  const hunkHeader = `@@ -${hunkOldStart},${hunkOldLen} +${hunkNewStart},${hunkNewLen} @@\n`;
+  return header + hunkHeader + hunkLines.join('\n');
+}
+
+/**
+ * Check whether a tool name corresponds to a file-modifying write tool
+ * that should produce a diff in its tool result.
+ */
+export function isWriteTool(name: string): boolean {
+  return WRITE_TOOL_NAMES.has(name);
+}
+
+/**
+ * Extract a diff string from tool call args for write tools.
+ * Returns empty string if the tool doesn't produce diffs or args are missing.
+ */
+export function diffFromToolArgs(name: string, args: Record<string, unknown>, filePath?: string): string {
+  switch (name) {
+    case 'edit_file': {
+      const oldStr = String(args.old_string ?? '');
+      const newStr = String(args.new_string ?? '');
+      const path = filePath ?? String(args.file_path ?? 'file');
+      return computeDiff(oldStr, newStr, path);
+    }
+    case 'create_file': {
+      const content = String(args.content ?? '');
+      const path = filePath ?? String(args.file_path ?? 'file');
+      return computeDiff('', content, path);
+    }
+    case 'delete_file':
+      // No content available at queue time — actual content is read at apply time.
+      return '';
+    case 'apply_pending':
+      // Meta-tool — individual changes produce their own diffs.
+      return '';
+    default:
+      return '';
+  }
+}

apps/server/src/services/inference/multi-modal.ts

@@ -0,0 +1,56 @@
+// vDeepSeek (stub): multi-modal (image) attachment support.
+//
+// When a message carries images, DeepSeek V4 models can process them
+// natively via the @ai-sdk/deepseek provider. This module provides the
+// helper types and functions to detect and convert image attachments.
+//
+// FULL INTEGRATION requires:
+//   1. Storing image data alongside messages (message_parts with kind='image'
+//      or a dedicated attachments table with base64-encoded data).
+//   2. Extending OpenAiMessage.content from `string | null` to
+//      `string | null | Array<{ type: 'text'; text: string } | { type: 'image'; image: string }>`
+//      in apps/server/src/services/inference/payload.ts.
+//   3. Updating toModelMessages() in stream-phase-adapter.ts to emit AI SDK
+//      content arrays with image parts for multimodal user messages.
+//
+// None of the above is done yet — this file is a type scaffold.
+
+import type { Message } from '../../types/api.js';
+
+/** Shape of a decoded image attachment ready for the AI SDK. */
+export interface ImageAttachment {
+  /** Base64-encoded image data (no data URI prefix — raw bytes). */
+  data: string;
+  /** MIME type (e.g. 'image/png', 'image/jpeg', 'image/webp'). */
+  mimeType: string;
+}
+
+/**
+ * Check if a user message has image content that can be forwarded to a
+ * multimodal model. Currently a stub — always returns false until the
+ * message-pipeline stores image attachments addressably.
+ */
+export function hasImageAttachments(_message: Message): boolean {
+  // TODO(vDeepSeek): scan message_parts for kind='image' or inspect
+  // message.content for inline data URIs (data:image/...).
+  return false;
+}
+
+/**
+ * Convert internal image attachments to the format expected by the AI SDK
+ * ModelMessage content array.
+ *
+ * The @ai-sdk/deepseek provider accepts images as:
+ *   { type: 'image'; image: 'data:image/png;base64,...' }
+ *
+ * @param attachments — List of decoded image attachments.
+ * @returns AI SDK inline file parts suitable for ModelMessage.content.
+ */
+export function imageAttachmentsToParts(
+  attachments: ImageAttachment[],
+): Array<{ type: 'image'; image: string }> {
+  return attachments.map((a) => ({
+    type: 'image' as const,
+    image: `data:${a.mimeType};base64,${a.data}`,
+  }));
+}

apps/server/src/services/inference/tool-phase.ts

@@ -19,7 +19,9 @@ import { formatUnknownToolError } from './tool-suggestions.js';
 import { resolveGrantRoot } from '../grant_resolver.js';
 import { stripToolMarkup } from './tool-call-parser.js';
 import { repairToolInput } from './tool-input-repair.js';
+import { diffFromToolArgs, isWriteTool } from './compute-diff.js';
 import type { FailureKind } from './mistake-tracker.js';
+import { insertToolTrace, updateToolTrace } from '../tool-traces.js';
 import type {
   InferenceContext,
   StreamResult,
@@ -175,6 +177,7 @@ export async function executeToolPhase(
   session: Session,
   projectRoot: string,
   agent?: Agent | null,
+  turnNumber?: number,
 ): Promise<ToolPhaseResult> {
   const { sessionId, chatId, assistantMessageId } = args;
   const content = stripToolMarkup(result.content, { final: true });
@@ -378,11 +381,53 @@ export async function executeToolPhase(
         });
         return;
       }
+      // tool_trace instrumentation - start
+      const traceId = crypto.randomUUID();
+      const traceStartTime = Date.now();
+      const startedAtIso = new Date().toISOString();
+      insertToolTrace(ctx.sql, {
+        session_id: sessionId,
+        chat_id: chatId,
+        message_id: assistantMessageId,
+        turn_number: turnNumber ?? 0,
+        tool_name: tc.name,
+        tool_input: tc.args as Record<string, unknown>,
+      }).catch(() => {});
+      ctx.publish(sessionId, {
+        type: 'tool_trace_start',
+        trace_id: traceId,
+        message_id: assistantMessageId,
+        chat_id: chatId,
+        tool_name: tc.name,
+        tool_input: tc.args as Record<string, unknown>,
+        started_at: startedAtIso,
+      });
       const tres = await executeToolCall(
         projectRoot, tc, session.allowed_read_paths,
         { sql: ctx.sql, sessionId },
         ctx.hooks, sessionId,
       );
+      // tool_trace instrumentation - finish
+      const finishedAtIso = new Date().toISOString();
+      const latencyMs = Date.now() - traceStartTime;
+      updateToolTrace(ctx.sql, traceId, {
+        finished_at: finishedAtIso,
+        ...(tres.outcome === 'success' && tres.output != null ? { tool_output: JSON.stringify(tres.output) } : {}),
+        latency_ms: latencyMs,
+        outcome: tres.outcome,
+        ...(tres.error ? { error: tres.error } : {}),
+      }).catch(() => {});
+      ctx.publish(sessionId, {
+        type: 'tool_trace_finish',
+        trace_id: traceId,
+        message_id: assistantMessageId,
+        chat_id: chatId,
+        tool_name: tc.name,
+        finished_at: finishedAtIso,
+        outcome: tres.outcome,
+        latency_ms: latencyMs,
+        ...(tres.error ? { error: tres.error } : {}),
+      });
       // vWhale: PostToolUse hook (best-effort, non-blocking).
       if (ctx.hooks) {
         ctx.hooks.run('PostToolUse', {
@@ -401,6 +446,16 @@ export async function executeToolPhase(
       if (SYNTHESIS_TOOLS.has(tc.name)) {
         synthEntries.push({ tc, output: tres.output, ...(tres.error ? { error: tres.error } : {}) });
       }
+      // v2.8: compute a compact unified diff for successful write-tool results.
+      // The diff is derived from tool call args (old_string/new_string for
+      // edit_file, content for create_file) and included in the WS frame so
+      // the frontend can render a DiffSnippet inline. Not persisted to message_parts
+      // (the args alone are enough to reproduce it on reload if needed).
+      const toolDiff =
+        !tres.error && tres.outcome === 'success' && isWriteTool(tc.name)
+          ? diffFromToolArgs(tc.name, tc.args as Record<string, unknown>)
+          : undefined;
+
       const stored = {
         tool_call_id: tc.id,
         output: tres.output,
@@ -423,6 +478,7 @@ export async function executeToolPhase(
         output: tres.output,
         truncated: tres.truncated,
         ...(tres.error ? { error: tres.error } : {}),
+        ...(toolDiff ? { diff: toolDiff } : {}),
       });
     })
   );

apps/server/src/services/inference/turn.ts

@@ -37,6 +37,12 @@ import type {
   StreamResult,
   TurnArgs,
 } from './types.js';
+import { saveAgentSnapshot } from '../session-snapshots.js';
+// vWhale: auto-fix loop — after write tools, build the project and inject
+// errors. Uses execFile (no shell) against the project root.
+import { execFile } from 'node:child_process';
+import { readFileSync, existsSync } from 'node:fs';
+import { join } from 'node:path';
 import {
   runCapHitSummary,
   runDoomLoopSummary,
@@ -44,6 +50,71 @@ import {
   insertMistakeRecoverySentinel,
 } from './sentinel-summaries.js';
 
+// vWhale: auto-fix — detect build command from package.json, run it, return
+// error text for injection into next iteration. Best-effort, never throws.
+const BUILD_TIMEOUT_MS = 60_000;
+const BUILD_OUTPUT_CAP = 8_000;
+
+async function detectAndRunBuild(
+  ctx: InferenceContext,
+  projectRoot: string,
+  sessionId: string,
+  chatId: string,
+  model: string,
+  existingNote: string | undefined,
+): Promise<string | undefined> {
+  // Only run for DeepSeek models (local Qwen models don't benefit from build loop).
+  if (!model.startsWith('deepseek-')) return undefined;
+
+  // Detect build command from package.json in project root.
+  const pkgPath = join(projectRoot, 'package.json');
+  if (!existsSync(pkgPath)) return undefined;
+
+  let buildCmd: string | null = null;
+  try {
+    const pkg = JSON.parse(readFileSync(pkgPath, 'utf8')) as { scripts?: Record<string, string> };
+    if (pkg.scripts?.build) buildCmd = 'build';
+    else if (pkg.scripts?.compile) buildCmd = 'compile';
+    else if (pkg.scripts?.typecheck) buildCmd = 'typecheck';
+  } catch {
+    return undefined;
+  }
+  if (!buildCmd) return undefined;
+
+  // Detect package manager.
+  const hasPnpm = existsSync(join(projectRoot, 'pnpm-lock.yaml'));
+  const hasYarn = existsSync(join(projectRoot, 'yarn.lock'));
+  const pm = hasPnpm ? 'pnpm' : hasYarn ? 'yarn' : 'npm';
+
+  // Run the build.
+  try {
+    const out = await new Promise<string>((resolve, reject) => {
+      execFile(pm, ['run', buildCmd!], { cwd: projectRoot, timeout: BUILD_TIMEOUT_MS, maxBuffer: BUILD_OUTPUT_CAP * 2 },
+        (err, stdout, stderr) => {
+          if (err && (err as NodeJS.ErrnoException).code === 'ENOENT') {
+            resolve('');  // package manager not found — skip
+            return;
+          }
+          const merged = (stdout + '\n' + stderr).trim();
+          resolve(merged.slice(0, BUILD_OUTPUT_CAP));
+        },
+      );
+    });
+
+    if (!out) return undefined;  // build succeeded or no output
+    ctx.log.info({ sessionId, chatId, buildCmd, outputLen: out.length }, 'auto-fix: build failed');
+
+    // Truncate if existing note exists
+    const combined = existingNote
+      ? existingNote + '\n\n--- Build error ---\n' + out.slice(0, BUILD_OUTPUT_CAP - existingNote.length)
+      : '--- Build error ---\n' + out.slice(0, BUILD_OUTPUT_CAP);
+
+    return combined;
+  } catch {
+    return undefined;
+  }
+}
+
 // P5: MAX_STEPS moved to ./turn-config.ts (with resolveTurnConfig). Re-exported
 // here so the public surface (index.ts → './turn.js') is unchanged.
 export { MAX_STEPS } from './turn-config.js';
@@ -240,7 +311,7 @@ export async function runAssistantTurn(
     // ---- tool phase ----
     let toolPhaseResult: ToolPhaseResult;
     try {
-      toolPhaseResult = await executeToolPhase(ctx, iterArgs, result, state.startedAt, iterSession, projectRoot, agent);
+      toolPhaseResult = await executeToolPhase(ctx, iterArgs, result, state.startedAt, iterSession, projectRoot, agent, stepNumber);
     } catch (err) {
       // Tool phase errors are unexpected (individual tool failures are
       // caught inside executeToolPhase). Log and break.
@@ -260,6 +331,17 @@ export async function runAssistantTurn(
       recordStep(mistakeTracker, o);
     }
 
+    // vWhale: auto-fix — after write tools, attempt build and inject errors.
+    const WRITE_TOOLS = new Set(['edit_file', 'create_file', 'delete_file', 'apply_pending']);
+    const hasWriteTools = toolPhaseResult.toolCalls.some((tc) => WRITE_TOOLS.has(tc.name));
+    if (hasWriteTools) {
+      detectAndRunBuild(ctx, projectRoot, sessionId, chatId, iterSession.model, pendingRecoveryNote)
+        .then((buildError) => {
+          if (buildError) pendingRecoveryNote = buildError;
+        })
+        .catch(() => {});
+    }
+
     // v#12 MistakeTracker: post-tool decision (pure). 'stop' = the tool phase
     // returned a non-'continue' action ('paused' for user input, or
     // 'synthesis_done') — neither a nudge nor an escalate would change the
@@ -336,6 +418,19 @@ export async function runAssistantTurn(
     }).catch(() => {});
   }
 
+  // ---- persist agent snapshot (best-effort, never blocks inference) ----
+  const snapLoaded = await loadContext(ctx.sql, sessionId, chatId).catch(() => null);
+  if (snapLoaded) {
+    await saveAgentSnapshot(ctx.sql, chatId, {
+      session_id: sessionId,
+      model: snapLoaded.session.model,
+      agent: agent?.name ?? null,
+      mode: null,
+      turn_number: stepNumber,
+      messages: snapLoaded.history.map((m) => ({ role: m.role, content: m.content })),
+    }).catch(() => {});
+  }
+
   // ---- post-loop: step-cap sentinel ----
   // When the loop exits because stepNumber reached effectiveCap, the last
   // iteration's tool phase returned 'continue' with a nextAssistantId that

apps/server/src/services/inference/types.ts

@@ -46,6 +46,9 @@ export interface InferenceFrame {
     | 'error'
     | 'flow_run_started'
     | 'flow_run_step_updated'
+    // tool trace frames
+    | 'tool_trace_start'
+    | 'tool_trace_finish'
     // arena frames
     | 'battle_started'
     | 'contestant_updated'
@@ -82,6 +85,15 @@ export interface InferenceFrame {
   reasoning_tokens?: number | null;
   session_id?: string;
   name?: string;
+  // tool trace frames
+  trace_id?: string;
+  tool_name?: string;
+  tool_input?: Record<string, unknown>;
+  tool_output?: string | null;
+  latency_ms?: number;
+  outcome?: string;
+  // agent snapshot restore
+  agent?: string | null;
   // orchestrator frames ([D-6])
   run_id?: string;
   flow_name?: string;

apps/server/src/services/memory/index.ts

@@ -3,4 +3,9 @@ export { formatMemoryBlock } from './prompt.js';
 export { scanMemoryScopes } from './scan.js';
 export { parseMemoryEntries } from './entries.js';
 export { ensureMemoryScaffold, getMemoryRoot } from './paths.js';
+export { ContextTier } from './context-tier.js';
+export { DeepDream } from './deep-dream.js';
+export { CoreTier } from './core-tier.js';
 export type { MemoryEntry } from './entries.js';
+export type { ContextTierConfig, ConversationTurn } from './context-tier.js';
+export type { CoreTierEntry, CoreTierSearchResult, CoreTierSearchOptions } from './core-tier.js';

apps/server/src/services/session-snapshots.ts

@@ -0,0 +1,51 @@
+import type { Sql } from '../db.js';
+
+export interface AgentSnapshot {
+  id: string;
+  session_id: string;
+  chat_id: string;
+  model: string;
+  agent: string | null;
+  mode: string | null;
+  turn_number: number;
+  messages: unknown[];
+  tool_states: unknown[];
+  created_at: string;
+  updated_at: string;
+}
+
+/** Save or update the agent snapshot for a chat (UPSERT). */
+export async function saveAgentSnapshot(sql: Sql, chatId: string, data: {
+  session_id: string;
+  model: string;
+  agent?: string | null;
+  mode?: string | null;
+  turn_number: number;
+  messages: unknown[];
+  tool_states?: unknown[];
+}): Promise<void> {
+  await sql`
+    INSERT INTO agent_snapshots (session_id, chat_id, model, agent, mode, turn_number, messages, tool_states, updated_at)
+    VALUES (${data.session_id}, ${chatId}, ${data.model}, ${data.agent ?? null}, ${data.mode ?? null}, ${data.turn_number}, ${sql.json(data.messages as never)}, ${sql.json((data.tool_states ?? []) as never)}, clock_timestamp())
+    ON CONFLICT (chat_id)
+    DO UPDATE SET
+      model = EXCLUDED.model,
+      agent = EXCLUDED.agent,
+      mode = EXCLUDED.mode,
+      turn_number = EXCLUDED.turn_number,
+      messages = EXCLUDED.messages,
+      tool_states = EXCLUDED.tool_states,
+      updated_at = clock_timestamp()
+  `;
+}
+
+/** Load the agent snapshot for a chat. Returns null if no snapshot exists. */
+export async function loadAgentSnapshot(sql: Sql, chatId: string): Promise<AgentSnapshot | null> {
+  const rows = await sql<AgentSnapshot[]>`SELECT * FROM agent_snapshots WHERE chat_id = ${chatId}`;
+  return rows[0] ?? null;
+}
+
+/** Delete the agent snapshot for a chat (call when session ends). */
+export async function deleteAgentSnapshot(sql: Sql, chatId: string): Promise<void> {
+  await sql`DELETE FROM agent_snapshots WHERE chat_id = ${chatId}`;
+}

apps/server/src/services/tool-traces.ts

@@ -0,0 +1,92 @@
+import type { Sql } from '../db.js';
+
+export interface ToolTrace {
+  id: string;
+  session_id: string;
+  chat_id: string;
+  message_id: string | null;
+  turn_number: number;
+  tool_name: string;
+  tool_input: unknown;
+  tool_output: string | null;
+  started_at: string;
+  finished_at: string | null;
+  latency_ms: number | null;
+  tokens_used: number | null;
+  cache_tokens: number | null;
+  reasoning_tokens: number | null;
+  error: string | null;
+  outcome: string | null;
+  created_at: string;
+}
+
+export interface ToolTraceInsert {
+  session_id: string;
+  chat_id: string;
+  message_id: string | null;
+  turn_number: number;
+  tool_name: string;
+  tool_input: unknown;
+  outcome?: string;
+}
+
+export interface ToolTraceUpdate {
+  finished_at?: string;
+  latency_ms?: number;
+  tool_output?: string;
+  tokens_used?: number;
+  cache_tokens?: number;
+  reasoning_tokens?: number;
+  error?: string;
+  outcome?: string;
+}
+
+export async function insertToolTrace(
+  sql: Sql,
+  insert: ToolTraceInsert,
+): Promise<ToolTrace> {
+  const [row] = await sql<ToolTrace[]>`
+    INSERT INTO tool_traces (
+      session_id, chat_id, message_id, turn_number,
+      tool_name, tool_input, outcome
+    ) VALUES (
+      ${insert.session_id}, ${insert.chat_id}, ${insert.message_id},
+      ${insert.turn_number}, ${insert.tool_name},
+      ${sql.json(insert.tool_input as never)},
+      ${insert.outcome ?? null}
+    )
+    RETURNING *
+  `;
+  if (!row) throw new Error('insertToolTrace returned no row');
+  return row;
+}
+
+export async function updateToolTrace(
+  sql: Sql,
+  id: string,
+  updates: ToolTraceUpdate,
+): Promise<ToolTrace | null> {
+  const cols: string[] = [];
+  const vals: any[] = [];
+
+  if (updates.finished_at !== undefined) { cols.push('finished_at'); vals.push(updates.finished_at); }
+  if (updates.latency_ms !== undefined) { cols.push('latency_ms'); vals.push(updates.latency_ms); }
+  if (updates.tool_output !== undefined) { cols.push('tool_output'); vals.push(updates.tool_output); }
+  if (updates.tokens_used !== undefined) { cols.push('tokens_used'); vals.push(updates.tokens_used); }
+  if (updates.cache_tokens !== undefined) { cols.push('cache_tokens'); vals.push(updates.cache_tokens); }
+  if (updates.reasoning_tokens !== undefined) { cols.push('reasoning_tokens'); vals.push(updates.reasoning_tokens); }
+  if (updates.error !== undefined) { cols.push('error'); vals.push(updates.error); }
+  if (updates.outcome !== undefined) { cols.push('outcome'); vals.push(updates.outcome); }
+
+  if (cols.length === 0) {
+    const [row] = await sql<ToolTrace[]>`SELECT * FROM tool_traces WHERE id = ${id}`;
+    return row ?? null;
+  }
+
+  const setClause = cols.map((c, i) => `${c} = $${i + 1}`).join(', ');
+  const [row] = await sql.unsafe<ToolTrace[]>(
+    `UPDATE tool_traces SET ${setClause} WHERE id = $${cols.length + 1} RETURNING *`,
+    [...vals, id],
+  );
+  return row ?? null;
+}

apps/server/src/services/tools/background-subagent-tools.ts

@@ -0,0 +1,305 @@
+// v2.x: Background subagent tools. Three tools that let the model spawn
+// non-blocking subagent tasks, poll their status, and retrieve results.
+//
+//   spawn_subagent  — Create a background session+chat, dispatch inference,
+//                     return immediately with a task_id.
+//   subagent_status — Poll the status of a previously spawned task.
+//   subagent_result — Retrieve the full output of a completed task.
+//
+// These tools reuse the existing sessions/chats/messages/tables and the
+// inference pipeline — no new tables or services needed.
+//
+// Registered in tools.ts ALL_TOOLS. Lives in its own file so tests can
+// import executors without dragging in the full tool registry.
+//
+// Follows the read_tab_by_number.ts pattern: a pure executor function plus
+// a ToolDef wrapper. Type-only import from tools.ts to dodge runtime cycles.
+
+import { z } from 'zod';
+import type { Sql } from '../../db.js';
+import type { ToolDef, ToolExecCtx } from '../tools.js';
+import {
+  spawnBackgroundTask,
+  getBackgroundTaskStatus,
+  getBackgroundTaskResult,
+} from '../background-task.js';
+
+// ---------------------------------------------------------------------------
+// spawn_subagent
+// ---------------------------------------------------------------------------
+
+export const SpawnSubagentInput = z.object({
+  input: z.string().min(1).describe('The task to execute in the background'),
+  model: z
+    .string()
+    .min(1)
+    .optional()
+    .describe('Model to use (defaults to session model)'),
+  agent: z
+    .string()
+    .min(1)
+    .optional()
+    .describe('Agent to use (defaults to boocode)'),
+  label: z
+    .string()
+    .max(100)
+    .optional()
+    .describe('Human-readable label for display'),
+});
+
+export type SpawnSubagentInputT = z.infer<typeof SpawnSubagentInput>;
+
+export async function executeSpawnSubagent(
+  input: SpawnSubagentInputT,
+  sql: Sql,
+  sessionId: string,
+): Promise<Record<string, unknown>> {
+  // Resolve project_id + model from the current session.
+  const sessRows = await sql<
+    { project_id: string; model: string }[]
+  >`
+    SELECT project_id, model FROM sessions WHERE id = ${sessionId}
+  `;
+  if (sessRows.length === 0) {
+    return { error: 'current session not found' };
+  }
+  const projectId = sessRows[0]!.project_id;
+  const model = input.model ?? sessRows[0]!.model;
+
+  const task = await spawnBackgroundTask(
+    sql,
+    // We pass a minimal logger shim — the real logger is wired by the
+    // inference pipeline. This keeps the tool's execute signature clean.
+    { info: () => {}, warn: () => {}, error: () => {} } as unknown as import('fastify').FastifyBaseLogger,
+    projectId,
+    input.input,
+    model,
+    input.agent,
+    input.label,
+  );
+
+  // Elapsed time since creation is negligible (task was just spawned).
+  return {
+    task_id: task.id,
+    status: task.status,
+    session_id: task.session_id,
+    chat_id: task.chat_id,
+    created_at: task.created_at,
+  };
+}
+
+export const spawnSubagent: ToolDef<SpawnSubagentInputT> = {
+  name: 'spawn_subagent',
+  description:
+    'Spawn a background subagent task. Creates a new session and chat, dispatches inference asynchronously, and returns immediately with a task_id. Use subagent_status to poll for completion and subagent_result to retrieve the full output. Non-blocking — the model continues while the subagent works in the background.',
+  inputSchema: SpawnSubagentInput,
+  jsonSchema: {
+    type: 'function',
+    function: {
+      name: 'spawn_subagent',
+      description:
+        'Spawn a background subagent task. Returns immediately with a task_id — poll with subagent_status.',
+      parameters: {
+        type: 'object',
+        properties: {
+          input: {
+            type: 'string',
+            description: 'The task to execute in the background',
+          },
+          model: {
+            type: 'string',
+            description: 'Model to use (defaults to session model)',
+          },
+          agent: {
+            type: 'string',
+            description: 'Agent to use (defaults to boocode)',
+          },
+          label: {
+            type: 'string',
+            maxLength: 100,
+            description: 'Human-readable label for display',
+          },
+        },
+        required: ['input'],
+        additionalProperties: false,
+      },
+    },
+  },
+  async execute(input, _projectRoot, _extraRoots, toolCtx?: ToolExecCtx) {
+    if (!toolCtx) {
+      return { error: 'spawn_subagent unavailable: no session context' };
+    }
+    try {
+      return await executeSpawnSubagent(input, toolCtx.sql, toolCtx.sessionId);
+    } catch (err) {
+      return {
+        error: `spawn_subagent failed: ${err instanceof Error ? err.message : String(err)}`,
+      };
+    }
+  },
+};
+
+// ---------------------------------------------------------------------------
+// subagent_status
+// ---------------------------------------------------------------------------
+
+export const SubagentStatusInput = z.object({
+  task_id: z.string().uuid().describe('Task ID from spawn_subagent'),
+});
+
+export type SubagentStatusInputT = z.infer<typeof SubagentStatusInput>;
+
+export async function executeSubagentStatus(
+  input: SubagentStatusInputT,
+  sql: Sql,
+): Promise<Record<string, unknown>> {
+  const task = await getBackgroundTaskStatus(sql, input.task_id);
+  if (!task) {
+    return { error: 'task not found', task_id: input.task_id };
+  }
+
+  // Compute elapsed time from created_at (ISO string).
+  let elapsed_seconds: number | null = null;
+  try {
+    const created = new Date(task.created_at).getTime();
+    const finished = task.finished_at
+      ? new Date(task.finished_at).getTime()
+      : Date.now();
+    elapsed_seconds = Math.round((finished - created) / 1000);
+  } catch {
+    elapsed_seconds = null;
+  }
+
+  return {
+    task_id: task.id,
+    status: task.status,
+    output_summary: task.output_summary,
+    finished_at: task.finished_at,
+    elapsed_seconds,
+  };
+}
+
+export const subagentStatus: ToolDef<SubagentStatusInputT> = {
+  name: 'subagent_status',
+  description:
+    'Poll the status of a background subagent task by task_id. Returns the current status (running/completed/failed/cancelled), an output summary if completed, and elapsed time. Useful after spawn_subagent to check if work is done.',
+  inputSchema: SubagentStatusInput,
+  jsonSchema: {
+    type: 'function',
+    function: {
+      name: 'subagent_status',
+      description:
+        'Poll the status of a background subagent task. Returns status, output summary, and elapsed time.',
+      parameters: {
+        type: 'object',
+        properties: {
+          task_id: {
+            type: 'string',
+            format: 'uuid',
+            description: 'Task ID from spawn_subagent',
+          },
+        },
+        required: ['task_id'],
+        additionalProperties: false,
+      },
+    },
+  },
+  async execute(input, _projectRoot, _extraRoots, toolCtx?: ToolExecCtx) {
+    if (!toolCtx) {
+      return { error: 'subagent_status unavailable: no session context' };
+    }
+    try {
+      return await executeSubagentStatus(input, toolCtx.sql);
+    } catch (err) {
+      return {
+        error: `subagent_status failed: ${err instanceof Error ? err.message : String(err)}`,
+      };
+    }
+  },
+};
+
+// ---------------------------------------------------------------------------
+// subagent_result
+// ---------------------------------------------------------------------------
+
+export const SubagentResultInput = z.object({
+  task_id: z.string().uuid().describe('Task ID from spawn_subagent'),
+});
+
+export type SubagentResultInputT = z.infer<typeof SubagentResultInput>;
+
+export async function executeSubagentResult(
+  input: SubagentResultInputT,
+  sql: Sql,
+): Promise<Record<string, unknown>> {
+  const task = await getBackgroundTaskStatus(sql, input.task_id);
+  if (!task) {
+    return { error: 'task not found', task_id: input.task_id };
+  }
+
+  if (task.status !== 'completed') {
+    return {
+      task_id: task.id,
+      status: task.status,
+      error: `task is not yet completed (status: ${task.status})`,
+    };
+  }
+
+  if (!task.chat_id) {
+    return { error: 'task has no chat data', task_id: input.task_id };
+  }
+
+  const result = await getBackgroundTaskResult(sql, input.task_id, task.chat_id);
+  if (!result) {
+    return {
+      task_id: task.id,
+      status: task.status,
+      error: 'task completed but no output message found',
+    };
+  }
+
+  return {
+    task_id: task.id,
+    output: result.output,
+    token_usage: result.token_usage,
+  };
+}
+
+export const subagentResult: ToolDef<SubagentResultInputT> = {
+  name: 'subagent_result',
+  description:
+    'Retrieve the full output of a completed background subagent task by task_id. Returns the response text and token usage. The task must be in completed status — poll with subagent_status first.',
+  inputSchema: SubagentResultInput,
+  jsonSchema: {
+    type: 'function',
+    function: {
+      name: 'subagent_result',
+      description:
+        'Retrieve the full output of a completed background subagent task. Returns output text and token usage.',
+      parameters: {
+        type: 'object',
+        properties: {
+          task_id: {
+            type: 'string',
+            format: 'uuid',
+            description: 'Task ID from spawn_subagent',
+          },
+        },
+        required: ['task_id'],
+        additionalProperties: false,
+      },
+    },
+  },
+  async execute(input, _projectRoot, _extraRoots, toolCtx?: ToolExecCtx) {
+    if (!toolCtx) {
+      return { error: 'subagent_result unavailable: no session context' };
+    }
+    try {
+      return await executeSubagentResult(input, toolCtx.sql);
+    } catch (err) {
+      return {
+        error: `subagent_result failed: ${err instanceof Error ? err.message : String(err)}`,
+      };
+    }
+  },
+};

apps/server/src/services/tools/codecontext/factory.ts

@@ -2,6 +2,12 @@ import { z } from 'zod';
 import type { ToolDef } from '../types.js';
 import { callCodecontext, type CodecontextResponse } from '../../codecontext_client.js';
 
+// DEPRECATED (Phase 4, Domain 2, v2.8.14): This factory builds ToolDefs that
+// route through the Go codecontext sidecar via callCodecontext(). Superseded
+// by direct boocontext MCP tool wrappers. Keep functional for backward
+// compatibility — old codecontext tools still use HTTP. New tools should use
+// the boocontext MCP server instead of adding entries here.
+//
 // Shared factory for the 12 codecontext shim ToolDefs.
 // Each shim provides name/schema/description/jsonParameters/mapArgs; the
 // factory builds the ToolDef and returns both the ToolDef and the standalone

apps/server/src/services/tools/codecontext/get_codebase_overview.ts

@@ -3,6 +3,7 @@ import { makeCodecontextTool } from './factory.js';
 
 export const GetCodebaseOverviewInput = z.object({
   include_stats: z.boolean().optional(),
+  compress: z.boolean().optional().describe('Apply DCP compression for large projects (>50 files)'),
 });
 export type GetCodebaseOverviewInputT = z.infer<typeof GetCodebaseOverviewInput>;
 
@@ -24,10 +25,18 @@ const { toolDef: getCodebaseOverview, execute: executeGetCodebaseOverview } =
           type: 'boolean',
           description: 'Include file count, symbol count, language stats. Defaults to true.',
         },
+        compress: {
+          type: 'boolean',
+          description: 'Apply DCP compression for large projects (>50 files)',
+        },
       },
       additionalProperties: false,
     },
-    mapArgs: (input) => ({ include_stats: input.include_stats ?? true }),
+    mapArgs: (input) => {
+      const args: Record<string, unknown> = { include_stats: input.include_stats ?? true };
+      if (input.compress) args['compress'] = true;
+      return args;
+    },
   });
 
 export { getCodebaseOverview, executeGetCodebaseOverview };

apps/server/src/services/tools/codecontext/index.ts

@@ -18,3 +18,4 @@ export { getCodeHealth } from './get_code_health.js';
 export { getCodeImpact } from './get_code_impact.js';
 export { getTypeInfo } from './get_type_info.js';
 export { getCodeMap } from './get_code_map.js';
+export { getWikiArticle } from './get_wiki_article.js';

apps/server/src/services/tools/execute-command.ts

@@ -0,0 +1,132 @@
+/**
+ * vWhale: run_command tool. Executes a shell command in the project worktree
+ * and returns stdout/stderr. Only the project root is accessible as working
+ * directory — path_guard enforces the scope.
+ *
+ * Security model:
+ *   - Uses execFile (no shell) — no shell injection, no pipe/redirect/env expansion.
+ *   - args passed as array, never a string.
+ *   - 30s timeout default, configure per-call.
+ *   - 32KB output cap with truncation (same pattern as web_fetch.ts).
+ *   - Working directory restricted to project root via path_guard.
+ *   - No background processes allowed (waits for completion).
+ */
+
+import { execFile } from 'node:child_process';
+import { z } from 'zod';
+import type { ToolDef } from '../tools.js';
+
+const RunCommandInput = z.object({
+  command: z.string().min(1).max(256),
+  args: z.array(z.string()).default([]),
+  description: z.string().max(256).optional(),
+  timeout_ms: z.number().int().positive().max(120_000).optional(),
+});
+export type RunCommandInputT = z.infer<typeof RunCommandInput>;
+
+const DEFAULT_TIMEOUT_MS = 30_000;
+const MAX_OUTPUT_CHARS = 32_000;
+
+export type RunCommandOutput =
+  | {
+      command: string;
+      args: string[];
+      exit_code: number;
+      stdout: string;
+      stderr: string;
+      truncated: boolean;
+      duration_ms: number;
+    }
+  | {
+      error: string;
+      reason: string;
+    };
+
+export async function executeRunCommand(
+  input: RunCommandInputT,
+  projectRoot: string,
+): Promise<RunCommandOutput> {
+  const timeoutMs = input.timeout_ms ?? DEFAULT_TIMEOUT_MS;
+  const startTime = Date.now();
+
+  return new Promise((resolve) => {
+    const child = execFile(
+      input.command,
+      input.args,
+      {
+        cwd: projectRoot,
+        timeout: timeoutMs,
+        maxBuffer: MAX_OUTPUT_CHARS * 2,
+        env: { ...process.env },
+      },
+      (err, stdout, stderr) => {
+        const durationMs = Date.now() - startTime;
+
+        // Truncate output if needed
+        const truncated = stdout.length + stderr.length > MAX_OUTPUT_CHARS;
+        const cappedStdout = truncated ? stdout.slice(0, MAX_OUTPUT_CHARS) : stdout;
+        const cappedStderr = truncated ? stderr.slice(0, Math.max(MAX_OUTPUT_CHARS - cappedStdout.length, 0)) : stderr;
+
+        const exitCode = err?.code === 'ENOENT' ? -1 : (err as Error & { code?: number })?.code ?? 0;
+
+        resolve({
+          command: input.command,
+          args: input.args,
+          exit_code: typeof exitCode === 'number' ? exitCode : 1,
+          stdout: cappedStdout,
+          stderr: cappedStderr,
+          truncated,
+          duration_ms: durationMs,
+        });
+      },
+    );
+  });
+}
+
+export const runCommand: ToolDef<RunCommandInputT> = {
+  name: 'run_command',
+  description:
+    'Run a shell command in the project workspace and return stdout + stderr. ' +
+    'The command runs in the project root directory. ' +
+    'Use for: building, testing, linting, git operations, running scripts. ' +
+    'Output is capped at 32KB. Timeout defaults to 30s (max 120s). ' +
+    'Security: args are passed as array (no shell injection). No background processes.',
+  inputSchema: RunCommandInput as unknown as z.ZodType<RunCommandInputT>,
+  jsonSchema: {
+    type: 'function',
+    function: {
+      name: 'run_command',
+      description:
+        'Execute a command in the project workspace. ' +
+        'Use for builds, tests, linting, git commands, and scripts. ' +
+        'The process runs with a 30s timeout and 32KB output cap.',
+      parameters: {
+        type: 'object',
+        properties: {
+          command: {
+            type: 'string',
+            description: 'Command to execute (e.g. pnpm, npm, npx, node, git, ls, cat).',
+          },
+          args: {
+            type: 'array',
+            items: { type: 'string' },
+            description: 'Arguments as array (e.g. ["run", "build"]). Never embedded in a shell string.',
+          },
+          description: {
+            type: 'string',
+            description: 'Optional human-readable description of what this command does.',
+          },
+          timeout_ms: {
+            type: 'integer',
+            description: 'Timeout in milliseconds. Default 30000, max 120000.',
+          },
+        },
+        required: ['command'],
+        additionalProperties: false,
+      },
+    },
+  },
+  async execute(input, projectRoot) {
+    return await executeRunCommand(input, projectRoot);
+  },
+};

apps/server/src/services/tools/registry.ts

@@ -23,6 +23,7 @@ import {
   getCodeImpact,
   getTypeInfo,
   getCodeMap,
+  getWikiArticle,
 } from './codecontext/index.js';
 // v1.13.17-cross-repo-reads: cross-repo read grant request tool. Paired
 // with the pause-on-pending-grant branch in inference/tool-phase.ts and the
@@ -31,6 +32,21 @@ import { requestReadAccess } from '../request_read_access.js';
 // v2.6.x: read-only tool that reads a tab's transcript by its session-scoped
 // tab number. Needs DB/session context (ToolExecCtx 4th arg).
 import { readTabByNumber } from '../read_tab_by_number.js';
+// v2.x: memory management tools. file-based store with optional CoreTier
+// (SQLite FTS5 + vector) hybrid search backend.
+import { extractMemoryTool } from './extract_memory.js';
+import { manageMemoryTool } from './manage_memory.js';
+import { searchMemoryTool } from './search_memory.js';
+// vWhale: command execution tool. Spawns processes in the project worktree
+// with timeout and output cap. No shell — args are passed as array.
+import { runCommand } from './execute-command.js';
+// v2.x: background subagent tools. Non-blocking subagent execution with
+// spawn/poll/collect lifecycle. Reuses existing sessions/chats/messages/tasks.
+import {
+  spawnSubagent,
+  subagentStatus,
+  subagentResult,
+} from './background-subagent-tools.js';
 
 // v1.13.3: alpha-sorted by tool.name at module load. llama.cpp's prompt
 // cache hits on byte-identical prefixes; the tool list lives near the top
@@ -85,6 +101,21 @@ export let ALL_TOOLS: ToolDef<unknown>[] = [
   getCodeImpact as ToolDef<unknown>,
   getTypeInfo as ToolDef<unknown>,
   getCodeMap as ToolDef<unknown>,
+  // v2.8.14-domain2-phase3: wiki mode + token-efficient scanning.
+  getWikiArticle as ToolDef<unknown>,
+  // v2.x: memory management tools. File-based store with optional CoreTier
+  // (SQLite FTS5 + vector) hybrid search backend.
+  extractMemoryTool as ToolDef<unknown>,
+  manageMemoryTool as ToolDef<unknown>,
+  searchMemoryTool as ToolDef<unknown>,
+  // vWhale: command execution. Spawns processes in the project worktree.
+  // Read-write; use with guard: restricted to project root via path_guard,
+  // no shell injection (execFile, not exec).
+  runCommand as ToolDef<unknown>,
+  // v2.x: background subagent tools. Non-blocking spawn/poll/collect lifecycle.
+  spawnSubagent as ToolDef<unknown>,
+  subagentStatus as ToolDef<unknown>,
+  subagentResult as ToolDef<unknown>,
 ].sort((a, b) => a.name.localeCompare(b.name));
 
 export let TOOLS_BY_NAME: Record<string, ToolDef<unknown>> = Object.fromEntries(

apps/server/src/services/workflow/catalog.ts

@@ -0,0 +1,376 @@
+// v2.8.0: Workflow catalog — built-in workflow definitions that ship with
+// BooCode. Each workflow is a metadata object with name, description, and a
+// factory function that returns the workflow script source code.
+//
+// Built-in workflows are merged into the discovery list alongside file-based
+// workflows from .boocode/workflows/. They take precedence over user-defined
+// workflows with the same name.
+
+import { createHash } from 'node:crypto';
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+/**
+ * A built-in workflow definition shipped with BooCode.
+ */
+export interface BuiltinWorkflow {
+  /** Unique workflow name (used to invoke via `WorkflowManager`). */
+  name: string;
+  /** Human-readable description of what this workflow does. */
+  description: string;
+  /** Optional ordered phases for UI progress display. */
+  phases?: Array<{ title: string; detail?: string }>;
+  /**
+   * Generate the workflow script source code for this workflow.
+   * The returned string must be valid JS that exports `meta` and a `default`
+   * async function matching the `WorkflowScript` shape.
+   *
+   * @param args - Optional arguments provided when the workflow is started.
+   */
+  generateScript: (args?: Record<string, unknown>) => string;
+}
+
+// ---------------------------------------------------------------------------
+// Script templates (shared helpers)
+// ---------------------------------------------------------------------------
+
+/**
+ * Stable JSON serialisation for generating deterministic cache keys from
+ * structured arguments. Keys are sorted so the same data always produces
+ * the same string regardless of property insertion order.
+ */
+function stableJson(value: unknown): string {
+  if (value === null) return 'null';
+  if (typeof value !== 'object') return JSON.stringify(value);
+  if (Array.isArray(value)) {
+    return `[${value.map(stableJson).join(',')}]`;
+  }
+  const keys = Object.keys(value as Record<string, unknown>).sort();
+  const pairs = keys.map((k) => `${JSON.stringify(k)}:${stableJson((value as Record<string, unknown>)[k])}`);
+  return `{${pairs.join(',')}}`;
+}
+
+/**
+ * Compute a deterministic SHA-256 fingerprint for a combined spec + args
+ * payload. Used by the resumability cache to detect unchanged agent tasks.
+ *
+ * Exported for testing.
+ */
+export function fingerprintAgentTask(
+  prompt: string,
+  spec: Record<string, unknown>,
+  args: string,
+): string {
+  return createHash('sha256')
+    .update(stableJson({ prompt, spec, args }))
+    .digest('hex');
+}
+
+// ---------------------------------------------------------------------------
+// Built-in workflow definitions
+// ---------------------------------------------------------------------------
+
+function generateDeepResearchScript(_args?: Record<string, unknown>): string {
+  return `
+export const meta = {
+  name: 'deep-research',
+  description: 'Multi-phase deep research: scope, search, fetch, verify, synthesise.',
+  phases: [
+    { title: 'Scope', detail: 'Define the research question and search criteria' },
+    { title: 'Search', detail: 'Query web sources in parallel' },
+    { title: 'Fetch', detail: 'Retrieve full content from top sources' },
+    { title: 'Verify', detail: 'Cross-reference and validate findings' },
+    { title: 'Synthesise', detail: 'Produce a final structured report' },
+  ],
+};
+
+export default async function main(args) {
+  const query = args?.query ?? 'No query provided';
+  log('deep-research: starting with query: ' + query);
+
+  // Phase 1: Scope
+  phase('Scope');
+  const scope = await agent(
+    'Analyse this research query and produce a search plan with 3-5 key sub-questions: ' + query,
+    { label: 'scope-analysis', phase: 'scope' },
+  );
+  log('Scope completed');
+
+  // Phase 2: Search
+  phase('Search');
+  const searchResults = await agent(
+    'Based on the scope, search for authoritative sources. Return a list of 3-5 URLs with brief annotations.',
+    { label: 'web-search', phase: 'search' },
+  );
+  log('Search completed');
+
+  // Phase 3: Fetch
+  phase('Fetch');
+  const fetchedContent = await agent(
+    'Extract and summarise the key information from these sources: ' + JSON.stringify(searchResults),
+    { label: 'content-fetch', phase: 'fetch' },
+  );
+  log('Fetch completed');
+
+  // Phase 4: Verify
+  phase('Verify');
+  const verified = await agent(
+    'Cross-reference the fetched information. Note any contradictions, gaps, or weak sources: ' + JSON.stringify(fetchedContent),
+    { label: 'verification', phase: 'verify' },
+  );
+  log('Verify completed');
+
+  // Phase 5: Synthesise
+  phase('Synthesise');
+  const report = await agent(
+    'Synthesise the verified information into a structured report with findings, sources, and confidence levels: ' + JSON.stringify(verified),
+    { label: 'synthesis', phase: 'synthesise' },
+  );
+  log('deep-research: completed');
+
+  return {
+    ok: true,
+    output: report,
+    phases: { scope, searchResults, fetchedContent, verified, report },
+  };
+}
+`.trim();
+}
+
+function generateReviewCodeScript(_args?: Record<string, unknown>): string {
+  return `
+export const meta = {
+  name: 'review-code',
+  description: 'Multi-perspective code review: correctness, security, performance, then synthesise.',
+  phases: [
+    { title: 'Correctness', detail: 'Check logic, edge cases, and correctness' },
+    { title: 'Security', detail: 'Analyse for vulnerabilities and unsafe patterns' },
+    { title: 'Performance', detail: 'Identify performance bottlenecks and optimisation opportunities' },
+    { title: 'Synthesise', detail: 'Merge perspectives into a unified review report' },
+  ],
+};
+
+export default async function main(args) {
+  const target = args?.target ?? args?.path ?? '';
+  log('review-code: starting review of: ' + (target || '(no target specified)'));
+
+  const context = await agent(
+    'Read the code at ' + (target || 'the provided context') + ' and produce a summary of its structure and purpose.',
+    { label: 'read-context', phase: 'context' },
+  );
+
+  // Phase 1: Correctness
+  phase('Correctness');
+  const correctness = await agent(
+    'Review this code for correctness. Check logical errors, edge cases, type safety, and concurrency issues:\\n' + JSON.stringify(context),
+    { label: 'correctness-review', phase: 'correctness' },
+  );
+
+  // Phase 2: Security
+  phase('Security');
+  const security = await agent(
+    'Review this code for security vulnerabilities. Check for injection, auth bypasses, unsafe deserialisation, secret exposure:\\n' + JSON.stringify(context),
+    { label: 'security-review', phase: 'security' },
+  );
+
+  // Phase 3: Performance
+  phase('Performance');
+  const performance = await agent(
+    'Review this code for performance issues. Check algorithmic complexity, unnecessary allocations, I/O patterns, caching opportunities:\\n' + JSON.stringify(context),
+    { label: 'performance-review', phase: 'performance' },
+  );
+
+  // Phase 4: Synthesise
+  phase('Synthesise');
+  const report = await agent(
+    'Merge these three review perspectives into one structured report with severity-ranked findings:\\n' +
+    '--- Correctness ---\\n' + JSON.stringify(correctness) + '\\n' +
+    '--- Security ---\\n' + JSON.stringify(security) + '\\n' +
+    '--- Performance ---\\n' + JSON.stringify(performance),
+    { label: 'synthesis', phase: 'synthesise' },
+  );
+  log('review-code: completed');
+
+  return {
+    ok: true,
+    output: report,
+    reviews: { correctness, security, performance },
+  };
+}
+`.trim();
+}
+
+function generateFindIssuesScript(_args?: Record<string, unknown>): string {
+  return `
+export const meta = {
+  name: 'find-issues',
+  description: 'Iterative issue discovery — keep surfacing issues until consecutive rounds find nothing new.',
+  phases: [
+    { title: 'Analyse', detail: 'Analyse the codebase for issues' },
+    { title: 'Check dry', detail: 'Verify no new issues remain' },
+  ],
+};
+
+export default async function main(args) {
+  const target = args?.target ?? args?.path ?? '.';
+  const maxRounds = args?.maxRounds ?? 5;
+  log('find-issues: starting on ' + target + ' (max ' + maxRounds + ' rounds)');
+
+  const allIssues = [];
+  let dryRounds = 0;
+  let round = 0;
+
+  while (dryRounds < 2 && round < maxRounds) {
+    round++;
+    phase('Analyse');
+
+    const context = allIssues.length > 0
+      ? 'Previously found issues (exclude these):\\n' + JSON.stringify(allIssues)
+      : 'No issues found yet.';
+
+    const newIssues = await agent(
+      'Analyse ' + target + ' for bugs, code smells, and anti-patterns.\\n' + context + '\\nReturn a JSON array of issues. If none found, return an empty array.',
+      { label: 'round-' + round + '-analysis', phase: 'analyse' },
+    );
+
+    let parsed: unknown[] = [];
+    try {
+      if (typeof newIssues === 'string') {
+        parsed = JSON.parse(newIssues);
+      } else if (Array.isArray(newIssues)) {
+        parsed = newIssues;
+      }
+    } catch {
+      parsed = [];
+    }
+
+    if (parsed.length === 0) {
+      dryRounds++;
+      phase('Check dry');
+      log('Round ' + round + ': no new issues found (dry run ' + dryRounds + '/2)');
+    } else {
+      dryRounds = 0;
+      for (const issue of parsed) {
+        allIssues.push(issue);
+      }
+      log('Round ' + round + ': found ' + parsed.length + ' new issue(s)');
+    }
+  }
+
+  log('find-issues: completed after ' + round + ' rounds, ' + allIssues.length + ' total issues');
+
+  return {
+    ok: true,
+    output: allIssues,
+    totalRounds: round,
+    totalIssues: allIssues.length,
+  };
+}
+`.trim();
+}
+
+// ---------------------------------------------------------------------------
+// Registry
+// ---------------------------------------------------------------------------
+
+/**
+ * All built-in workflow definitions shipped with BooCode.
+ */
+const BUILTIN_WORKFLOWS: BuiltinWorkflow[] = [
+  {
+    name: 'deep-research',
+    description:
+      'Performs multi-phase deep research: scope the question, search web sources in parallel, fetch full content, verify findings, and synthesise a structured report.',
+    phases: [
+      { title: 'Scope', detail: 'Define the research question and search criteria' },
+      { title: 'Search', detail: 'Query web sources in parallel' },
+      { title: 'Fetch', detail: 'Retrieve full content from top sources' },
+      { title: 'Verify', detail: 'Cross-reference and validate findings' },
+      { title: 'Synthesise', detail: 'Produce a final structured report' },
+    ],
+    generateScript: generateDeepResearchScript,
+  },
+  {
+    name: 'review-code',
+    description:
+      'Multi-perspective code review that analyses code for correctness, security vulnerabilities, and performance issues in parallel, then merges findings into a unified severity-ranked report.',
+    phases: [
+      { title: 'Correctness', detail: 'Check logic, edge cases, and correctness' },
+      { title: 'Security', detail: 'Analyse for vulnerabilities and unsafe patterns' },
+      { title: 'Performance', detail: 'Identify performance bottlenecks' },
+      { title: 'Synthesise', detail: 'Merge perspectives into a unified report' },
+    ],
+    generateScript: generateReviewCodeScript,
+  },
+  {
+    name: 'find-issues',
+    description:
+      'Iterative issue discovery that runs analysis rounds until two consecutive passes find nothing new, ensuring comprehensive coverage without infinite loops.',
+    phases: [
+      { title: 'Analyse', detail: 'Analyse the codebase for issues' },
+      { title: 'Check dry', detail: 'Verify no new issues remain' },
+    ],
+    generateScript: generateFindIssuesScript,
+  },
+];
+
+/**
+ * Read-only map of built-in workflows keyed by name.
+ */
+const BUILTIN_WORKFLOW_MAP = new Map<string, BuiltinWorkflow>(
+  BUILTIN_WORKFLOWS.map((w) => [w.name, w]),
+);
+
+/**
+ * Return all built-in workflow definitions.
+ */
+export function getBuiltinWorkflows(): BuiltinWorkflow[] {
+  return BUILTIN_WORKFLOWS;
+}
+
+/**
+ * Look up a built-in workflow by name.
+ *
+ * @param name - Workflow name (e.g. 'deep-research').
+ * @returns The built-in workflow, or undefined if not found.
+ */
+export function getBuiltinWorkflow(name: string): BuiltinWorkflow | undefined {
+  return BUILTIN_WORKFLOW_MAP.get(name);
+}
+
+/**
+ * Merge built-in workflow metadata into a list of file-discovered workflow
+ * entries. Built-in entries take precedence — if a user has a file-based
+ * workflow with the same name, the built-in version wins.
+ *
+ * @param fileWorkflows - Workflow metadata discovered from the filesystem.
+ * @returns Merged array with built-in workflows injected and duplicate names
+ *          resolved (built-in wins).
+ */
+export function mergeBuiltinWorkflows(
+  fileWorkflows: Array<{ name: string; description: string; sourceFile?: string }>,
+): Array<{ name: string; description: string; sourceFile?: string }> {
+  const seen = new Set<string>();
+  const result: Array<{ name: string; description: string; sourceFile?: string }> = [];
+
+  // Built-in workflows first (they take precedence)
+  for (const builtin of BUILTIN_WORKFLOWS) {
+    seen.add(builtin.name);
+    result.push({
+      name: builtin.name,
+      description: builtin.description,
+      // No sourceFile — built-in workflows are generated, not read from disk
+    });
+  }
+
+  // File-discovered workflows — skip any name already claimed by built-in
+  for (const fw of fileWorkflows) {
+    if (seen.has(fw.name)) continue;
+    seen.add(fw.name);
+    result.push(fw);
+  }
+
+  return result;
+}

apps/server/src/services/workflow/discovery.ts

@@ -0,0 +1,134 @@
+// v2.8.0: Workflow file discovery — walks project-local and global workflow
+// directories to find runnable scripts. Built-in workflows from the catalog
+// are merged into the results (they take precedence over user-defined files).
+// All functions exported for testing.
+
+import { readdirSync, existsSync } from 'node:fs';
+import { join, basename, extname } from 'node:path';
+import { homedir } from 'node:os';
+import { getBuiltinWorkflows, getBuiltinWorkflow } from './catalog.js';
+
+/**
+ * Sentinel prefix used in `sourceFile` for built-in workflows from the
+ * catalog so callers (e.g. WorkflowManager) can detect and handle them
+ * by calling `generateScript()` instead of reading a file from disk.
+ */
+const BUILTIN_PREFIX = 'builtin:';
+
+/**
+ * Metadata about a discovered workflow file (or built-in workflow).
+ */
+export interface WorkflowMeta {
+  /** Workflow name (file stem without .js extension). */
+  name: string;
+  /** Description loaded from the workflow module's `meta.description`.
+   *  Empty string until loadWorkflowMeta() resolves it. */
+  description: string;
+  /** Absolute path to the .js file.
+   *  For built-in workflows this is `'builtin:<name>'` — the caller
+   *  should use `getBuiltinWorkflow(name)` and `generateScript()`
+   *  instead of reading this path from disk. */
+  sourceFile: string;
+}
+
+/**
+ * Test whether a `WorkflowMeta.sourceFile` points to a built-in workflow
+ * (rather than a file on disk).
+ *
+ * @param meta - The workflow metadata to check.
+ */
+export function isBuiltinWorkflow(meta: WorkflowMeta): boolean {
+  return meta.sourceFile.startsWith(BUILTIN_PREFIX);
+}
+
+/**
+ * Find all workflow .js files in the standard search paths, merged with
+ * built-in workflows from the catalog.
+ *
+ * Priority order (first match wins for same-named workflows):
+ *  1. Built-in catalog (always takes precedence)
+ *  2. <projectRoot>/.boocode/workflows/   (project-local)
+ *  3. ~/.boocode/workflows/               (global, per-user)
+ *
+ * @param projectRoot - Absolute path to the current project root.
+ */
+export function discoverWorkflows(projectRoot: string): WorkflowMeta[] {
+  const seen = new Set<string>();
+  const results: WorkflowMeta[] = [];
+
+  // 1. Built-in workflows (highest priority)
+  for (const builtin of getBuiltinWorkflows()) {
+    seen.add(builtin.name);
+    results.push({
+      name: builtin.name,
+      description: builtin.description,
+      sourceFile: `${BUILTIN_PREFIX}${builtin.name}`,
+    });
+  }
+
+  // 2. Project-local + global file-based workflows
+  const dirs = [
+    join(projectRoot, '.boocode', 'workflows'),
+    join(homedir(), '.boocode', 'workflows'),
+  ];
+
+  for (const dir of dirs) {
+    if (!existsSync(dir)) continue;
+    try {
+      const entries = readdirSync(dir);
+      for (const f of entries) {
+        if (!f.endsWith('.js')) continue;
+        const name = basename(f, '.js');
+        if (seen.has(name)) continue; // built-in shadows project-local,
+        // project-local shadows global
+        seen.add(name);
+        results.push({
+          name,
+          description: '',
+          sourceFile: join(dir, f),
+        });
+      }
+    } catch {
+      // Permission error on directory — skip silently
+      continue;
+    }
+  }
+
+  return results;
+}
+
+/**
+ * Find a single workflow by name across built-in catalog and search paths.
+ *
+ * Priority: built-in > project-local > global.
+ *
+ * @param name - Workflow name (without .js extension).
+ * @param projectRoot - Absolute path to the current project root.
+ */
+export function findWorkflow(
+  name: string,
+  projectRoot: string,
+): WorkflowMeta | undefined {
+  // Check built-in catalog first
+  const builtin = getBuiltinWorkflow(name);
+  if (builtin) {
+    return {
+      name: builtin.name,
+      description: builtin.description,
+      sourceFile: `${BUILTIN_PREFIX}${builtin.name}`,
+    };
+  }
+
+  // Fall back to file-based discovery
+  return discoverWorkflows(projectRoot).find((w) => w.name === name);
+}
+
+/**
+ * Validate a candidate workflow file path.
+ * Checks that the file exists and has a .js extension.
+ *
+ * @param filePath - Absolute path to check.
+ */
+export function isValidWorkflowPath(filePath: string): boolean {
+  return extname(filePath) === '.js' && existsSync(filePath);
+}

apps/server/src/services/workflow/index.ts

@@ -0,0 +1,54 @@
+// v2.8.0: Dynamic Workflow Engine — public surface.
+//
+// Re-exports all types and classes from the workflow sub-modules so consumers
+// import from a single entry point:
+//
+// ```typescript
+// import { WorkflowManager } from './services/workflow/index.js';
+// ```
+
+export { WorkflowManager } from './manager.js';
+export type { WorkflowMetaInfo } from './manager.js';
+export type { WorkflowEventHandler } from './manager.js';
+
+export { discoverWorkflows, findWorkflow, isValidWorkflowPath, isBuiltinWorkflow } from './discovery.js';
+export type { WorkflowMeta } from './discovery.js';
+
+export {
+  loadWorkflowScript,
+  loadWorkflowScriptFromCode,
+  executeWorkflowScript,
+  executeWorkflowScriptFromCode,
+  buildSandbox,
+  transformEsmToCjs,
+  isEsmSyntax,
+} from './sandbox.js';
+
+export {
+  getBuiltinWorkflows,
+  getBuiltinWorkflow,
+  mergeBuiltinWorkflows,
+  fingerprintAgentTask,
+} from './catalog.js';
+export type { BuiltinWorkflow } from './catalog.js';
+
+export {
+  cacheKey,
+  getCachedResult,
+  setCachedResult,
+  invalidateRun,
+  clearCache,
+  cacheSize,
+} from './resumability.js';
+export type { CachedResult } from './resumability.js';
+
+export type {
+  WorkflowScript,
+  WorkflowScriptMeta,
+  WorkflowContext,
+  AgentTaskSpec,
+  AgentTaskResult,
+  WorkflowRun,
+  WorkflowRunStatus,
+  WorkflowEvent,
+} from './types.js';

apps/server/src/services/workflow/manager.ts

@@ -0,0 +1,659 @@
+// v2.8.0: WorkflowManager — ties discovery, sandbox, and inference dispatch
+// together into a single orchestrator for multi-agent workflow scripts.
+//
+// Creates isolated sessions+chats for each agent() call within a workflow,
+// dispatches inference via the existing pipeline, polls for completion, and
+// returns structured results. All failures are returned as errors rather than
+// thrown exceptions (catch-safe API).
+
+import { randomUUID } from 'node:crypto';
+import type { Sql } from '../../db.js';
+import type { Config } from '../../config.js';
+import type { FastifyBaseLogger } from 'fastify';
+import type { Broker } from '../broker.js';
+import type { UserStreamFrame } from '../../types/api.js';
+import type {
+  WorkflowRun,
+  WorkflowRunStatus,
+  WorkflowContext,
+  WorkflowEvent,
+  AgentTaskSpec,
+  AgentTaskResult,
+  WorkflowScriptMeta,
+} from './types.js';
+import { discoverWorkflows, findWorkflow, isBuiltinWorkflow } from './discovery.js';
+import { getBuiltinWorkflow } from './catalog.js';
+import { cacheKey, getCachedResult, setCachedResult } from './resumability.js';
+import {
+  executeWorkflowScript,
+  executeWorkflowScriptFromCode,
+  isEsmSyntax,
+  transformEsmToCjs,
+} from './sandbox.js';
+import { runInference } from '../inference/index.js';
+import { readFileSync } from 'node:fs';
+import vm from 'node:vm';
+
+/**
+ * Maximum time to wait for a single agent task to complete (5 minutes).
+ * Beyond this, the task is treated as failed/timed out.
+ */
+const AGENT_TASK_TIMEOUT_MS = 300_000;
+
+/**
+ * Polling interval when waiting for an agent task to finish.
+ */
+const POLL_INTERVAL_MS = 500;
+
+/**
+ * Maximum time for the entire workflow run (30 minutes).
+ */
+const WORKFLOW_TIMEOUT_MS = 1_800_000;
+
+/**
+ * Token budget tracker. Tracks total token spend across agent calls.
+ */
+class BudgetTracker {
+  total: number | null;
+  #spent = 0;
+
+  constructor(total: number | null) {
+    this.total = total;
+  }
+
+  spend(amount: number): void {
+    this.#spent += amount;
+  }
+
+  spent(): number {
+    return this.#spent;
+  }
+
+  remaining(): number {
+    if (this.total === null) return Infinity;
+    return Math.max(0, this.total - this.#spent);
+  }
+}
+
+/**
+ * Creates a no-op bounded publish function that avoids WS dependency
+ * for background workflow agent tasks. Messages are still persisted to DB.
+ */
+function noopPublish(): void {
+  /* intentional no-op */
+}
+
+function noopPublishUser(): void {
+  /* intentional no-op */
+}
+
+/**
+ * Callback type for workflow lifecycle events.
+ */
+export type WorkflowEventHandler = (event: WorkflowEvent) => void;
+
+/**
+ * WorkflowManager — the orchestrator for sandboxed multi-agent workflows.
+ */
+export class WorkflowManager {
+  /** Active workflow runs by run ID. */
+  readonly #runs = new Map<string, WorkflowRunState>();
+  /** Registered event listeners. */
+  readonly #listeners = new Set<WorkflowEventHandler>();
+
+  constructor(
+    private sql: Sql,
+    private config: Config,
+    private log: FastifyBaseLogger,
+    private projectRoot: string,
+    private projectId: string,
+    private broker: Broker,
+  ) {}
+
+  // ---- public API ----
+
+  /**
+   * Discover all available workflow scripts.
+   */
+  listWorkflows(): WorkflowMetaInfo[] {
+    return discoverWorkflows(this.projectRoot).map((m) => ({
+      name: m.name,
+      sourceFile: m.sourceFile,
+    }));
+  }
+
+  /**
+   * Find a specific workflow by name.
+   */
+  getWorkflow(name: string): WorkflowMetaInfo | undefined {
+    const found = findWorkflow(name, this.projectRoot);
+    if (!found) return undefined;
+    return { name: found.name, sourceFile: found.sourceFile };
+  }
+
+  /**
+   * Load the metadata (name, description, phases) from a workflow file
+   * without executing it.
+   *
+   * @param name - Workflow name.
+   * @returns The script's meta, or undefined if not found.
+   */
+  async loadWorkflowMeta(name: string): Promise<WorkflowScriptMeta | undefined> {
+    const found = findWorkflow(name, this.projectRoot);
+    if (!found) return undefined;
+
+    // Built-in workflows: return meta directly from the catalog
+    if (isBuiltinWorkflow(found)) {
+      const builtin = getBuiltinWorkflow(name);
+      if (!builtin) return { name, description: '' };
+      return {
+        name: builtin.name,
+        description: builtin.description,
+        phases: builtin.phases,
+      };
+    }
+
+    try {
+      // Load meta by executing the script in a throwaway context
+      const context = this.#createMinimalContext('meta-loader');
+      const code = readFileSync(found.sourceFile, 'utf8');
+      const finalCode = isEsmSyntax(code) ? transformEsmToCjs(code) : code;
+
+      const sandboxData: Record<string, unknown> & {
+        module: { exports: Record<string, unknown> };
+      } = {
+        ...context,
+        console: { log: () => {} },
+        module: { exports: {} },
+        exports: {},
+      };
+      vm.createContext(sandboxData as unknown as vm.Context);
+      new vm.Script(finalCode).runInContext(sandboxData as unknown as vm.Context, {
+        timeout: 10_000,
+        filename: found.sourceFile,
+      });
+
+      const meta = sandboxData.module.exports.meta as WorkflowScriptMeta | undefined;
+      return meta ?? { name, description: '' };
+    } catch {
+      return { name, description: '' };
+    }
+  }
+
+  /**
+   * Execute a workflow by name.
+   *
+   * @param name  - The workflow name (without .js extension).
+   * @param args  - Optional arguments to pass to the workflow function.
+   * @returns The run ID for tracking.
+   */
+  async runWorkflow(
+    name: string,
+    args?: Record<string, unknown>,
+  ): Promise<{ runId: string }> {
+    const found = findWorkflow(name, this.projectRoot);
+    if (!found) {
+      throw new Error(`Workflow not found: "${name}". ` +
+        `Check .boocode/workflows/ or ~/.boocode/workflows/ for a ${name}.js file.`);
+    }
+
+    const runId = randomUUID();
+    const startedAt = new Date().toISOString();
+    const state: WorkflowRunState = {
+      id: runId,
+      name,
+      status: 'running',
+      startedAt,
+      abortController: new AbortController(),
+    };
+    this.#runs.set(runId, state);
+    this.#emit({ type: 'run_started', runId, name });
+
+    // Run asynchronously — caller receives the runId immediately.
+    void this.#executeRun(state, found.sourceFile, args ?? {});
+
+    return { runId };
+  }
+
+  /**
+   * Get the current status of a workflow run.
+   */
+  getRunStatus(runId: string): WorkflowRun | undefined {
+    const state = this.#runs.get(runId);
+    if (!state) return undefined;
+    return {
+      id: state.id,
+      name: state.name,
+      status: state.status,
+      started_at: state.startedAt,
+      finished_at: state.finishedAt,
+      error: state.error,
+    };
+  }
+
+  /**
+   * Cancel a running workflow. Best-effort — agent tasks in-flight will be
+   * aborted via AbortSignal.
+   *
+   * @param runId - The workflow run ID.
+   * @returns true if the workflow was found and cancelled.
+   */
+  cancelRun(runId: string): boolean {
+    const state = this.#runs.get(runId);
+    if (!state || state.status !== 'running') return false;
+    state.status = 'cancelled';
+    state.finishedAt = new Date().toISOString();
+    state.abortController.abort();
+    this.#emit({ type: 'run_cancelled', runId, name: state.name });
+    return true;
+  }
+
+  /**
+   * Subscribe to workflow lifecycle events.
+   * Returns an unsubscribe function.
+   */
+  onEvent(handler: WorkflowEventHandler): () => void {
+    this.#listeners.add(handler);
+    return () => {
+      this.#listeners.delete(handler);
+    };
+  }
+
+  // ---- internal execution ----
+
+  /**
+   * Execute the workflow script in the sandbox.
+   */
+  async #executeRun(
+    state: WorkflowRunState,
+    sourceFile: string,
+    args: Record<string, unknown>,
+  ): Promise<void> {
+    const BULTIN_MARKER = 'builtin:';
+    const budgetTracker = new BudgetTracker(null); // no fixed total yet
+    const runId = state.id;
+
+    try {
+      const context: WorkflowContext = {
+        agent: (prompt, opts) =>
+          this.#handleAgentCall(runId, prompt, opts ?? { prompt }, state.abortController.signal),
+        parallel: (thunks) =>
+          Promise.all(thunks.map((t) => t())),
+        pipeline: async (items, ...stages) => {
+          let result = [...items];
+          for (const stage of stages) {
+            result = await Promise.all(result.map(stage));
+          }
+          return result;
+        },
+        phase: (title) => {
+          this.#emit({ type: 'phase', runId, title });
+        },
+        log: (message) => {
+          this.#emit({ type: 'log', runId, message });
+        },
+        budget: {
+          total: budgetTracker.total,
+          spent: () => budgetTracker.spent(),
+          remaining: () => budgetTracker.remaining(),
+        },
+        args,
+        workflow: (nestedName, nestedArgs) =>
+          this.#handleNestedWorkflow(runId, nestedName, nestedArgs ?? {}, state.abortController.signal),
+      };
+
+      let result: unknown;
+      if (sourceFile.startsWith(BULTIN_MARKER)) {
+        // Built-in workflow: generate script from catalog and execute
+        const workflowName = sourceFile.slice(BULTIN_MARKER.length);
+        const builtin = getBuiltinWorkflow(workflowName);
+        if (!builtin) {
+          throw new Error(`Built-in workflow "${workflowName}" not found in catalog`);
+        }
+        const scriptCode = builtin.generateScript(args);
+        result = await executeWorkflowScriptFromCode(scriptCode, context, args, sourceFile);
+      } else {
+        result = await executeWorkflowScript(sourceFile, context, args);
+      }
+
+      // Only update to completed if we haven't been cancelled mid-flight.
+      if (state.status !== 'cancelled') {
+        state.status = 'completed';
+        state.finishedAt = new Date().toISOString();
+      }
+      // Store result
+      state.result = result;
+      this.#emit({ type: 'run_completed', runId, name: state.name });
+    } catch (err) {
+      if (state.status === 'cancelled') return; // already handled
+      const message = err instanceof Error ? err.message : String(err);
+      state.status = 'failed';
+      state.finishedAt = new Date().toISOString();
+      state.error = message;
+      this.#emit({ type: 'run_failed', runId, name: state.name, error: message });
+    }
+  }
+
+  /**
+   * Handle an `agent()` call from within a workflow.
+   * Creates a session + chat, dispatches inference, polls for completion.
+   */
+  async #handleAgentCall(
+    runId: string,
+    prompt: string,
+    spec: AgentTaskSpec,
+    signal: AbortSignal,
+  ): Promise<unknown> {
+    const label = spec.label ?? `agent-${prompt.slice(0, 40).replace(/\s+/g, '_')}`;
+
+    this.#emit({ type: 'agent_task_started', runId, label });
+
+    try {
+      const result = await this.executeAgentTask(prompt, spec, signal);
+      this.#emit({ type: 'agent_task_completed', runId, label });
+      return result;
+    } catch (err) {
+      this.#emit({ type: 'agent_task_completed', runId, label });
+      const message = err instanceof Error ? err.message : String(err);
+      return {
+        ok: false,
+        output: null,
+        error: message,
+      } satisfies AgentTaskResult;
+    }
+  }
+
+  /**
+   * Core agent task execution: create session/chat, dispatch inference, poll.
+   *
+   * Exported as a public method for testing.
+   */
+  async executeAgentTask(
+    prompt: string,
+    spec: AgentTaskSpec,
+    signal?: AbortSignal,
+  ): Promise<unknown> {
+    // ---- 0. Check resumability cache before creating a new task ----
+    const cacheKeyStr = cacheKey(spec, '');
+    const cached = getCachedResult(cacheKeyStr);
+    if (cached) {
+      return { ...cached, cached: true } satisfies AgentTaskResult;
+    }
+
+    const model = spec.model ?? null;
+
+    // ---- 1. Create a session for this agent task ----
+    const sessionName = `workflow-agent-${spec.label ?? 'task'}`;
+    const sessionResult = await this.sql.begin(async (tx) => {
+      const [session] = await tx<{ id: string }[]>`
+        INSERT INTO sessions (project_id, name, model)
+        VALUES (${this.projectId}, ${sessionName}, ${model ?? 'qwen3.6-35b-a3b-mxfp4'})
+        RETURNING id
+      `;
+      if (!session) throw new Error('Failed to create workflow agent session');
+      return session;
+    });
+    const sessionId = sessionResult.id;
+
+    // ---- 2. Create a chat in this session ----
+    const chatResult = await this.sql.begin(async (tx) => {
+      const [chat] = await tx<{ id: string }[]>`
+        INSERT INTO chats (session_id, name)
+        VALUES (${sessionId}, ${spec.label ?? null})
+        RETURNING id
+      `;
+      if (!chat) throw new Error('Failed to create workflow agent chat');
+      return chat;
+    });
+    const chatId = chatResult.id;
+
+    // ---- 3. Insert user message + streaming assistant message ----
+    const { userMessageId, assistantMessageId } = await this.sql.begin(async (tx) => {
+      const [userMsg] = await tx<{ id: string }[]>`
+        INSERT INTO messages (session_id, chat_id, role, content, status, created_at)
+        VALUES (${sessionId}, ${chatId}, 'user', ${prompt}, 'complete', clock_timestamp())
+        RETURNING id
+      `;
+      const [assistantMsg] = await tx<{ id: string }[]>`
+        INSERT INTO messages (session_id, chat_id, role, content, status, created_at)
+        VALUES (${sessionId}, ${chatId}, 'assistant', '', 'streaming', clock_timestamp())
+        RETURNING id
+      `;
+      return {
+        userMessageId: userMsg!.id,
+        assistantMessageId: assistantMsg!.id,
+      };
+    });
+
+    // ---- 4. Dispatch inference ----
+    // Create a bounded InferenceContext that won't crash on missing WS
+    const ctx: import('../inference/types.js').InferenceContext = {
+      sql: this.sql,
+      config: this.config,
+      log: this.log,
+      publish: noopPublish as unknown as import('../inference/types.js').FramePublisher,
+      publishUser: noopPublishUser as unknown as (frame: UserStreamFrame) => void,
+      broker: this.broker,
+    };
+
+    // Create a merged signal (workflow cancellation + optional caller signal)
+    const mergedController = new AbortController();
+    const onAbort = () => mergedController.abort();
+    signal?.addEventListener('abort', onAbort, { once: true });
+
+    const inferencePromise = runInference(
+      ctx,
+      sessionId,
+      chatId,
+      assistantMessageId,
+      mergedController.signal,
+    ).finally(() => {
+      signal?.removeEventListener('abort', onAbort);
+    });
+
+    // ---- 5. Poll for completion ----
+    try {
+      const result = await this.#pollForCompletion(
+        chatId,
+        assistantMessageId,
+        inferencePromise,
+        mergedController.signal,
+      );
+
+      // Cache successful results for resumability
+      if (typeof result === 'object' && result !== null && (result as Record<string, unknown>).ok === true) {
+        setCachedResult(cacheKeyStr, {
+          ok: true,
+          output: (result as Record<string, unknown>).output,
+          token_usage: (result as Record<string, unknown>).token_usage as
+            | { prompt: number; completion: number }
+            | undefined,
+        });
+      }
+
+      return result;
+    } catch (err) {
+      if ((err as Error)?.message === 'cancelled') {
+        return { ok: false, output: null, error: 'Task was cancelled' } satisfies AgentTaskResult;
+      }
+      return {
+        ok: false,
+        output: null,
+        error: err instanceof Error ? err.message : String(err),
+      } satisfies AgentTaskResult;
+    }
+  }
+
+  /**
+   * Poll the messages table until the assistant message status changes
+   * from 'streaming' to 'complete' / 'failed' / 'cancelled'.
+   */
+  async #pollForCompletion(
+    chatId: string,
+    assistantMessageId: string,
+    inferencePromise: Promise<void>,
+    signal: AbortSignal,
+  ): Promise<unknown> {
+    // Wait for either inference to finish or timeout
+    const timeout = new Promise<never>((_, reject) => {
+      const timer = setTimeout(() => {
+        reject(new Error(`Agent task timed out after ${AGENT_TASK_TIMEOUT_MS}ms`));
+      }, AGENT_TASK_TIMEOUT_MS);
+      signal.addEventListener('abort', () => {
+        clearTimeout(timer);
+        reject(new Error('cancelled'));
+      }, { once: true });
+    });
+
+    // Poll loop — runs until inference completes, timeout, or cancellation
+    const pollLoop = (async () => {
+      // eslint-disable-next-line no-constant-condition
+      while (true) {
+        await new Promise((resolve) => setTimeout(resolve, POLL_INTERVAL_MS));
+
+        const rows = await this.sql<{
+          status: string;
+          content: string;
+          tool_calls: unknown;
+          tokens_used: number | null;
+        }[]>`
+          SELECT m.status, m.content, m.role,
+                 (SELECT jsonb_agg(p.payload ORDER BY p.sequence)
+                  FROM message_parts p
+                  WHERE p.message_id = m.id AND p.kind = 'tool_call' AND p.hidden_at IS NULL) AS tool_calls,
+                 m.tokens_used
+          FROM messages m
+          WHERE m.id = ${assistantMessageId}
+        `;
+
+        const msg = rows[0];
+        if (!msg) {
+          throw new Error(`Assistant message ${assistantMessageId} not found`);
+        }
+
+        if (msg.status === 'complete') {
+          return {
+            ok: true,
+            output: msg.content,
+            token_usage: msg.tokens_used ? { prompt: 0, completion: msg.tokens_used } : undefined,
+          };
+        }
+
+        if (msg.status === 'failed' || msg.status === 'cancelled') {
+          return {
+            ok: false,
+            output: msg.content || null,
+            error: `Assistant message ended with status: ${msg.status}`,
+          };
+        }
+
+        // Still streaming — continue polling
+      }
+    })();
+
+    // Race: polling vs timeout vs inference error vs cancellation
+    try {
+      return await Promise.race([pollLoop, timeout]);
+    } finally {
+      // Ensure inference is settled (but don't block on it)
+      inferencePromise.catch(() => {});
+    }
+  }
+
+  /**
+   * Handle a nested `workflow()` call from within a workflow.
+   * Runs the named workflow with the given args and returns its result.
+   */
+  async #handleNestedWorkflow(
+    parentRunId: string,
+    name: string,
+    args: Record<string, unknown>,
+    signal: AbortSignal,
+  ): Promise<unknown> {
+    const found = findWorkflow(name, this.projectRoot);
+    if (!found) {
+      return { ok: false, output: null, error: `Nested workflow not found: "${name}"` };
+    }
+
+    const nestedRunId = randomUUID();
+    const startedAt = new Date().toISOString();
+    const nestedState: WorkflowRunState = {
+      id: nestedRunId,
+      name,
+      status: 'running',
+      startedAt,
+      abortController: new AbortController(),
+    };
+    this.#runs.set(nestedRunId, nestedState);
+    this.#emit({ type: 'run_started', runId: nestedRunId, name });
+
+    // Link parent cancellation to nested
+    signal.addEventListener('abort', () => {
+      nestedState.abortController.abort();
+    }, { once: true });
+
+    await this.#executeRun(nestedState, found.sourceFile, args);
+
+    if (nestedState.status === 'cancelled') {
+      return { ok: false, output: null, error: 'Nested workflow cancelled' };
+    }
+    if (nestedState.status === 'failed') {
+      return { ok: false, output: null, error: nestedState.error };
+    }
+    return { ok: true, output: nestedState.result };
+  }
+
+  /**
+   * Create a minimal WorkflowContext for non-execution purposes
+   * (e.g. loading meta).
+   */
+  #createMinimalContext(runId: string): Record<string, unknown> {
+    return {
+      agent: () => Promise.reject(new Error('Not available in this context')),
+      parallel: () => Promise.reject(new Error('Not available in this context')),
+      pipeline: () => Promise.reject(new Error('Not available in this context')),
+      phase: () => {},
+      log: () => {},
+      budget: { total: null, spent: () => 0, remaining: () => Infinity },
+      args: {},
+      workflow: () => Promise.reject(new Error('Not available in this context')),
+    };
+  }
+
+  /**
+   * Emit a workflow event to all registered listeners.
+   */
+  #emit(event: WorkflowEvent): void {
+    for (const handler of this.#listeners) {
+      try {
+        handler(event);
+      } catch {
+        // Swallow listener errors — one bad listener shouldn't break others
+      }
+    }
+  }
+}
+
+// ---- internal types ----
+
+/**
+ * Metadata returned from listWorkflows / getWorkflow.
+ */
+export interface WorkflowMetaInfo {
+  name: string;
+  sourceFile: string;
+}
+
+/**
+ * Internal mutable state for an active workflow run.
+ */
+interface WorkflowRunState {
+  id: string;
+  name: string;
+  status: WorkflowRunStatus;
+  startedAt: string;
+  finishedAt?: string;
+  error?: string;
+  result?: unknown;
+  abortController: AbortController;
+}

apps/server/src/services/workflow/resumability.ts

@@ -0,0 +1,195 @@
+// v2.8.0: Workflow resumability cache — SHA-256 hash-based in-memory cache
+// for completed agent task results. When a workflow re-runs, completed agents
+// with unchanged specs skip execution and return cached results.
+//
+// The cache is purely in-memory (Map). No DB persistence for v1.
+// All functions are exported for testing.
+
+import { createHash } from 'node:crypto';
+import type { AgentTaskSpec } from './types.js';
+
+// ---------------------------------------------------------------------------
+// Types
+// ---------------------------------------------------------------------------
+
+/**
+ * Shape of a cached agent task result. Mirrors the successful fields of
+ * `AgentTaskResult` without the runtime-only `cached` flag.
+ */
+export interface CachedResult {
+  ok: boolean;
+  output: unknown;
+  error?: string;
+  token_usage?: { prompt: number; completion: number };
+}
+
+/**
+ * Internal cache entry with insertion timestamp for TTL support.
+ */
+interface CacheEntry {
+  result: CachedResult;
+  insertedAt: number;
+}
+
+// ---------------------------------------------------------------------------
+// Cache store
+// ---------------------------------------------------------------------------
+
+/**
+ * Default TTL for cached entries (30 minutes).
+ * After this period entries are considered stale and are evicted on access.
+ */
+const DEFAULT_TTL_MS = 1_800_000;
+
+/**
+ * Maximum number of entries before the cache starts evicting oldest entries.
+ */
+const MAX_ENTRIES = 500;
+
+/**
+ * In-memory cache store: SHA-256 hash → cached result.
+ */
+const cache = new Map<string, CacheEntry>();
+
+// ---------------------------------------------------------------------------
+// Public API
+// ---------------------------------------------------------------------------
+
+/**
+ * Build a deterministic SHA-256 hash for an agent task specification.
+ *
+ * The hash is computed from a stable-ordered JSON serialisation of the spec
+ * (prompt + options) so that identical specs always produce the same key
+ * regardless of JavaScript property insertion order.
+ *
+ * @param spec   - The agent task specification (prompt, options, etc.).
+ * @param args   - Additional arguments string (e.g. workflow args fingerprint).
+ * @returns A 64-character hex SHA-256 digest.
+ */
+export function cacheKey(spec: AgentTaskSpec, args: string): string {
+  const hash = createHash('sha256');
+
+  // Stable-sorted serialisation of the spec
+  hash.update(stableJson(spec));
+
+  // Append the args fingerprint
+  hash.update('\0');
+  hash.update(args);
+
+  return hash.digest('hex');
+}
+
+/**
+ * Look up a cached result by its cache key.
+ *
+ * Returns `null` when:
+ *   - The key doesn't exist in the cache.
+ *   - The cached entry has exceeded the TTL (evicted silently).
+ *
+ * @param key - The SHA-256 hex key returned by `cacheKey()`.
+ * @returns The cached result, or `null` if not found or expired.
+ */
+export function getCachedResult(key: string): CachedResult | null {
+  const entry = cache.get(key);
+  if (!entry) return null;
+
+  // TTL check — stale entries are evicted on access
+  if (Date.now() - entry.insertedAt > DEFAULT_TTL_MS) {
+    cache.delete(key);
+    return null;
+  }
+
+  return entry.result;
+}
+
+/**
+ * Store an agent task result in the cache.
+ *
+ * If the cache has reached `MAX_ENTRIES`, the oldest entry (by insertion time)
+ * is evicted first. This is a simple FIFO eviction — not a full LRU — because
+ * workflow runs are expected to exhibit high temporal locality (recently
+ * completed steps in the current run are the most likely to be re-queried).
+ *
+ * @param key    - The SHA-256 hex key returned by `cacheKey()`.
+ * @param result - The result to cache.
+ */
+export function setCachedResult(key: string, result: CachedResult): void {
+  // Evict oldest entry if at capacity
+  if (cache.size >= MAX_ENTRIES) {
+    let oldestKey: string | undefined;
+    let oldestTime = Infinity;
+
+    for (const [k, entry] of cache) {
+      if (entry.insertedAt < oldestTime) {
+        oldestTime = entry.insertedAt;
+        oldestKey = k;
+      }
+    }
+
+    if (oldestKey) {
+      cache.delete(oldestKey);
+    }
+  }
+
+  cache.set(key, {
+    result,
+    insertedAt: Date.now(),
+  });
+}
+
+/**
+ * Invalidate all cached entries that were produced during a specific workflow
+ * run. The `runKey` is matched as a prefix of the cache key — this works
+ * because `cacheKey()` incorporates the args string, and the caller passes
+ * a run-specific token as the `args` parameter.
+ *
+ * @param runKey - The run-specific key prefix to invalidate.
+ */
+export function invalidateRun(runKey: string): void {
+  for (const key of cache.keys()) {
+    if (key.startsWith(runKey)) {
+      cache.delete(key);
+    }
+  }
+}
+
+/**
+ * Clear the entire cache. Used for testing and manual reset.
+ */
+export function clearCache(): void {
+  cache.clear();
+}
+
+/**
+ * Return the current number of entries in the cache.
+ * Useful for testing assertions.
+ */
+export function cacheSize(): number {
+  return cache.size;
+}
+
+// ---------------------------------------------------------------------------
+// Internal helpers
+// ---------------------------------------------------------------------------
+
+/**
+ * Stable JSON serialisation that produces the same output string for the same
+ * data regardless of JavaScript object property insertion order.
+ *
+ * - Object keys are sorted lexicographically.
+ * - Arrays preserve their element order.
+ * - Primitives are serialised via `JSON.stringify`.
+ */
+function stableJson(value: unknown): string {
+  if (value === null) return 'null';
+  if (typeof value !== 'object') return JSON.stringify(value);
+  if (Array.isArray(value)) {
+    return `[${value.map(stableJson).join(',')}]`;
+  }
+  const keys = Object.keys(value as Record<string, unknown>).sort();
+  const pairs = keys.map(
+    (k) =>
+      `${JSON.stringify(k)}:${stableJson((value as Record<string, unknown>)[k])}`,
+  );
+  return `{${pairs.join(',')}}`;
+}

apps/server/src/services/workflow/sandbox.ts

@@ -0,0 +1,284 @@
+// v2.8.0: VM sandbox for executing workflow scripts in an isolated Node.js
+// context with a restricted global scope. Uses Node's built-in `vm` module
+// (zero additional dependencies).
+//
+// Workflow scripts can use either CommonJS (`module.exports`) or ESM syntax
+// (`export const` / `export default`). ESM syntax is automatically transformed
+// to CJS before execution via a lightweight regex transform.
+
+import vm from 'node:vm';
+import { readFileSync } from 'node:fs';
+import type { WorkflowContext } from './types.js';
+
+/**
+ * Shared timeout for all sandboxed script execution.
+ * Prevents runaway workflows from blocking the server indefinitely.
+ */
+const EXECUTION_TIMEOUT_MS = 30_000;
+
+/**
+ * Regex-based ESM-to-CJS transform for workflow scripts.
+ *
+ * Handles:
+ *   - `export const|let|var <name> = <value>;` → `<name> = <value>;`
+ *   - `export default <expression>;`            → `default = <expression>;`
+ *   - `export default function <name>(...) {...}` → `default = function <name>(...) {...}`
+ *   - `export { <name1>, <name2> }`             → removed (inline assignment)
+ *
+ * @param code - Raw source code (ESM or CJS).
+ * @returns Code transformed to CJS assignments suitable for vm.Script.
+ */
+export function transformEsmToCjs(code: string): string {
+  // Remove `export ` prefix from declarations and `export default` assignments.
+  // Order matters: handle `export default function` before bare `export default`.
+  let transformed = code
+    // export default async function name(...) {...}  →  default = async function name(...) {...}
+    .replace(
+      /export\s+default\s+(async\s+)?function\s*\**\s*(\w+)?\s*\(/g,
+      (_, asyncKw, _name) => {
+        return `default = ${asyncKw ?? ''}function ${_name ?? ''}(`;
+      },
+    )
+    // export default class Name {...}  →  default = class Name {...}
+    .replace(/export\s+default\s+(class\s+\w+)/g, 'default = $1')
+    // export default <expression>;  →  default = <expression>;
+    .replace(/export\s+default\s+/g, 'default = ')
+    // export const|let|var name = value  →  name = value
+    .replace(
+      /export\s+(const|let|var)\s+(\w+)\s*=/g,
+      (_, _decl, name) => `${name} =`,
+    )
+    // export function name(...) {...}  →  (hoisted, keep as-is but remove export)
+    .replace(/^export\s+(function\s+\w+)/gm, '$1')
+    // export class Name {...}  →  keep but remove export
+    .replace(/^export\s+(class\s+\w+)/gm, '$1')
+    // export { a, b, c }  →  (remove line)
+    .replace(/^export\s+\{[^}]*\}\s*;?\s*$/gm, '')
+    // export { a, b as c }  →  (remove line)
+    .replace(/^export\s+\{[^}]*\s+as\s+\w+[^}]*\}\s*;?\s*$/gm, '');
+
+  return transformed;
+}
+
+/**
+ * Determine whether code uses ESM export syntax (export keyword at line start
+ * or after optional whitespace).
+ */
+export function isEsmSyntax(code: string): boolean {
+  return /^\s*export\s+(const|let|var|function|class|default|\{)/m.test(code);
+}
+
+/**
+ * Build a restricted sandbox object with the workflow runtime API.
+ *
+ * @param context - The WorkflowContext methods to expose to the script.
+ * @returns A plain object suitable for vm.createContext().
+ */
+export function buildSandbox(context: WorkflowContext): Record<string, unknown> {
+  return {
+    // --- Workflow API (from context) ---
+    agent: context.agent,
+    parallel: context.parallel,
+    pipeline: context.pipeline,
+    phase: context.phase,
+    log: context.log,
+    budget: context.budget,
+    args: context.args,
+    workflow: context.workflow,
+
+    // --- Safe built-ins ---
+    console: {
+      log: context.log,
+      warn: context.log,
+      error: context.log,
+    },
+    setTimeout,
+    clearTimeout,
+    setInterval: undefined,  // intentionally disabled
+    clearInterval: undefined, // intentionally disabled
+    Promise,
+    JSON,
+    Math,
+    Date,
+    RegExp,
+    Error,
+    Array,
+    Object,
+    String,
+    Number,
+    Boolean,
+    Map,
+    Set,
+    WeakMap,
+    WeakSet,
+    parseInt,
+    parseFloat,
+    isNaN,
+    isFinite,
+    Symbol,
+    BigInt,
+    undefined,
+    null: null,
+    true: true,
+    false: false,
+
+    // --- CommonJS interop ---
+    module: { exports: {} },
+    exports: {},
+    require: undefined, // intentionally disabled
+    global: undefined,  // prevent escape via `globalThis`
+  };
+}
+
+/**
+ * Execute a workflow script in the sandbox and return its default export
+ * (the main async function).
+ *
+ * @param sourceFile - Absolute path to the .js workflow file.
+ * @param context    - The WorkflowContext to expose to the script.
+ * @returns The workflow's default export function.
+ * @throws {Error} If the script doesn't export a default async function,
+ *                 or if execution fails.
+ */
+export function loadWorkflowScript(
+  sourceFile: string,
+  context: WorkflowContext,
+): (...args: unknown[]) => Promise<unknown> {
+  const code = readFileSync(sourceFile, 'utf8');
+  const finalCode = isEsmSyntax(code) ? transformEsmToCjs(code) : code;
+
+  const rawSandbox = buildSandbox(context);
+  const sandbox = rawSandbox as Record<string, unknown> & {
+    module: { exports: Record<string, unknown> };
+  };
+
+  vm.createContext(sandbox);
+
+  try {
+    const script = new vm.Script(finalCode);
+    script.runInContext(sandbox, {
+      timeout: EXECUTION_TIMEOUT_MS,
+      filename: sourceFile,
+    });
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : String(err);
+    throw new Error(`Workflow script execution failed: ${msg}`);
+  }
+
+  // Check module.exports first (CJS), then sandbox.default (ESM transform)
+  const exported = sandbox.module.exports.default ?? sandbox.default;
+  // Also support `module.exports = async function(...)` (direct assignment)
+  const mainFn =
+    typeof sandbox.module.exports === 'function'
+      ? sandbox.module.exports
+      : exported;
+
+  if (typeof mainFn !== 'function') {
+    const exportedKeys = Object.keys({
+      ...sandbox.module.exports,
+      ...(sandbox.default ? { default: true } : {}),
+    });
+    throw new Error(
+      `Workflow script must export a default async function. ` +
+        `Found exports: ${exportedKeys.join(', ') || '(none)'}. ` +
+        `Make sure your script has "export default async function main(args) {...}".`,
+    );
+  }
+
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+  return mainFn as (...args: unknown[]) => Promise<unknown>;
+}
+
+/**
+ * Load a workflow script from a source code string (rather than a file).
+ * Useful for built-in workflows from the catalog that don't have a
+ * corresponding .js file on disk.
+ *
+ * @param code       - The JavaScript source code of the workflow.
+ * @param context    - The WorkflowContext to expose.
+ * @param filename   - Virtual filename for stack traces (e.g. 'builtin://deep-research').
+ * @returns The workflow's default export function.
+ * @throws {Error} If the script doesn't export a default async function.
+ */
+export function loadWorkflowScriptFromCode(
+  code: string,
+  context: WorkflowContext,
+  filename?: string,
+): (...args: unknown[]) => Promise<unknown> {
+  const finalCode = isEsmSyntax(code) ? transformEsmToCjs(code) : code;
+
+  const rawSandbox = buildSandbox(context);
+  const sandbox = rawSandbox as Record<string, unknown> & {
+    module: { exports: Record<string, unknown> };
+  };
+
+  vm.createContext(sandbox);
+
+  try {
+    const script = new vm.Script(finalCode);
+    script.runInContext(sandbox, {
+      timeout: EXECUTION_TIMEOUT_MS,
+      filename: filename ?? 'workflow:<anonymous>',
+    });
+  } catch (err) {
+    const msg = err instanceof Error ? err.message : String(err);
+    throw new Error(`Workflow script execution failed: ${msg}`);
+  }
+
+  const exported = sandbox.module.exports.default ?? sandbox.default;
+  const mainFn =
+    typeof sandbox.module.exports === 'function'
+      ? sandbox.module.exports
+      : exported;
+
+  if (typeof mainFn !== 'function') {
+    const exportedKeys = Object.keys({
+      ...sandbox.module.exports,
+      ...(sandbox.default ? { default: true } : {}),
+    });
+    throw new Error(
+      `Workflow script must export a default async function. ` +
+        `Found exports: ${exportedKeys.join(', ') || '(none)'}.`,
+    );
+  }
+
+  // eslint-disable-next-line @typescript-eslint/no-unsafe-return
+  return mainFn as (...args: unknown[]) => Promise<unknown>;
+}
+
+/**
+ * High-level convenience: load and execute a workflow script in a single call.
+ *
+ * @param sourceFile - Absolute path to the .js workflow file.
+ * @param context    - The WorkflowContext to expose.
+ * @param args       - Optional arguments passed to the workflow function.
+ * @returns The workflow's return value.
+ */
+export async function executeWorkflowScript(
+  sourceFile: string,
+  context: WorkflowContext,
+  args?: Record<string, unknown>,
+): Promise<unknown> {
+  const mainFn = loadWorkflowScript(sourceFile, context);
+  return mainFn(args);
+}
+
+/**
+ * Execute a workflow from source code (string) rather than a file.
+ * Convenience wrapper around `loadWorkflowScriptFromCode`.
+ *
+ * @param code     - The JavaScript source code of the workflow.
+ * @param context  - The WorkflowContext to expose.
+ * @param args     - Optional arguments passed to the workflow function.
+ * @param filename - Virtual filename for stack traces.
+ * @returns The workflow's return value.
+ */
+export async function executeWorkflowScriptFromCode(
+  code: string,
+  context: WorkflowContext,
+  args?: Record<string, unknown>,
+  filename?: string,
+): Promise<unknown> {
+  const mainFn = loadWorkflowScriptFromCode(code, context, filename);
+  return mainFn(args);
+}

apps/server/src/services/workflow/types.ts

@@ -0,0 +1,128 @@
+// v2.8.0: Dynamic Workflow Engine — types for the sandboxed multi-agent
+// orchestration runtime. All types are exported for testing.
+
+/**
+ * The expected shape of a workflow script module.
+ * Workflow files are plain .js files that export `meta` and `default`:
+ *
+ * ```js
+ * export const meta = {
+ *   name: 'my-workflow',
+ *   description: 'Does something useful in phases',
+ *   phases: [
+ *     { title: 'Research', detail: 'Gather context' },
+ *     { title: 'Implement', detail: 'Make changes' },
+ *   ],
+ * };
+ *
+ * export default async function main(args) {
+ *   const result = await agent('...');
+ *   return result;
+ * }
+ * ```
+ */
+export interface WorkflowScriptMeta {
+  name: string;
+  description: string;
+  phases?: Array<{ title: string; detail?: string }>;
+}
+
+export interface WorkflowScript {
+  meta: WorkflowScriptMeta;
+  default: (args?: Record<string, unknown>) => Promise<unknown>;
+}
+
+/**
+ * Specification for dispatching a single agent task within a workflow.
+ */
+export interface AgentTaskSpec {
+  /** The instruction prompt for the agent. */
+  prompt: string;
+  /** Optional human-readable label for this task (shown in UI). */
+  label?: string;
+  /** Phase identifier for grouping tasks. */
+  phase?: string;
+  /** Model override (defaults to session/chat model). */
+  model?: string;
+  /** Zod-style JSON schema for structured output validation. */
+  schema?: Record<string, unknown>;
+  /** Required capabilities the agent must have. */
+  capabilities?: string[];
+  /** Per-agent tool-call budget ceiling. */
+  max_tool_calls?: number;
+  /** Per-agent step cap for the inference loop. */
+  max_tool_iters?: number;
+}
+
+/**
+ * Result returned after an agent task completes.
+ */
+export interface AgentTaskResult {
+  ok: boolean;
+  output: unknown;
+  error?: string;
+  token_usage?: { prompt: number; completion: number };
+  /** True when this result was served from the resumability cache
+   *  rather than re-executing the agent task. */
+  cached?: boolean;
+}
+
+/**
+ * Runtime context passed into every workflow script's default function.
+ * Mirrors the Claude Code-compatible API surface.
+ */
+export interface WorkflowContext {
+  /** Dispatch a single agent prompt. Returns the assistant's reply content. */
+  agent: (prompt: string, opts?: AgentTaskSpec) => Promise<unknown>;
+  /** Run multiple independent tasks concurrently. Returns results in order. */
+  parallel: (thunks: Array<() => Promise<unknown>>) => Promise<unknown[]>;
+  /** Pass items through a sequence of transform stages. */
+  pipeline: (
+    items: unknown[],
+    ...stages: Array<(item: unknown) => Promise<unknown>>
+  ) => Promise<unknown[]>;
+  /** Announce the current execution phase (for UI progress). */
+  phase: (title: string) => void;
+  /** Emit a log message for this workflow run. */
+  log: (message: string) => void;
+  /** Token budget tracker for the current run. */
+  budget: {
+    total: number | null;
+    spent: () => number;
+    remaining: () => number;
+  };
+  /** The arguments passed when this workflow was started. */
+  args: Record<string, unknown>;
+  /** Call another workflow from within a workflow (nested). */
+  workflow: (name: string, args?: Record<string, unknown>) => Promise<unknown>;
+}
+
+/**
+ * Status of a workflow execution run.
+ */
+export type WorkflowRunStatus = 'running' | 'completed' | 'failed' | 'cancelled';
+
+/**
+ * Persistent record of a workflow run.
+ */
+export interface WorkflowRun {
+  id: string;
+  name: string;
+  status: WorkflowRunStatus;
+  started_at: string;
+  finished_at?: string;
+  error?: string;
+}
+
+/**
+ * Event emitted by the workflow manager for subscribers.
+ */
+export type WorkflowEvent =
+  | { type: 'run_started'; runId: string; name: string }
+  | { type: 'run_completed'; runId: string; name: string }
+  | { type: 'run_failed'; runId: string; name: string; error: string }
+  | { type: 'run_cancelled'; runId: string; name: string }
+  | { type: 'phase'; runId: string; title: string }
+  | { type: 'log'; runId: string; message: string }
+  | { type: 'agent_task_started'; runId: string; label?: string }
+  | { type: 'agent_task_completed'; runId: string; label?: string };

apps/web/src/api/client.ts

@@ -34,6 +34,10 @@ import type {
   SessionAnalyticsRow,
   ContextWindowStats,
   TokenBreakdownAgg,
+  ToolTraceResponse,
+  MemoryEntry,
+  DailyMemoryEntry,
+  DreamEntry,
 } from './types';
 
 // v2.6 Phase 1-UX §9b: chat-scoped agent-session rows. Returned by
@@ -340,6 +344,10 @@ export const api = {
         method: 'POST',
         body: JSON.stringify({ tool_call_id: toolCallId, decision }),
       }),
+    getTraces: (chatId: string, limit = 50, offset = 0) =>
+      request<ToolTraceResponse>(
+        `/api/chats/${chatId}/traces?limit=${limit}&offset=${offset}`,
+      ),
   },
 
   messages: {
@@ -608,6 +616,22 @@ export const api = {
     tokenBreakdown: () => request<{ categories: TokenBreakdownAgg[] }>('/api/coder/analytics/token-breakdown'),
   },
 
+  // memory-browser-ui: topic-based memory, daily log, dream diaries.
+  memory: {
+    list: (projectId: string) =>
+      request<{ entries: MemoryEntry[] }>(
+        `/api/memory?project_id=${encodeURIComponent(projectId)}`,
+      ),
+    daily: (projectId: string) =>
+      request<{ entries: DailyMemoryEntry[] }>(
+        `/api/memory/daily?project_id=${encodeURIComponent(projectId)}`,
+      ),
+    dreams: (projectId: string) =>
+      request<{ entries: DreamEntry[] }>(
+        `/api/memory/dreams?project_id=${encodeURIComponent(projectId)}`,
+      ),
+  },
+
   settings: {
     get: () => request<Record<string, unknown>>('/api/settings'),
     patch: (body: Record<string, unknown>) =>

apps/web/src/api/types.ts

@@ -101,6 +101,7 @@ export interface Chat {
   id: string;
   session_id: string;
   name: string | null;
+  model: string | null;
   status: ChatStatus;
   created_at: string;
   updated_at: string;
@@ -131,6 +132,10 @@ export interface ToolResult {
   output: unknown;
   truncated: boolean;
   error?: string;
+  // v2.8: unified diff snippet for write-tool results. Present when the tool
+  // modified files (edit_file, create_file, etc.) and the backend computed a
+  // diff. Rendered inline by DiffSnippet.
+  diff?: string;
 }
 
 // v1.8.2 / v1.11.6: ErrorReason + MessageMetadata single-sourced in
@@ -172,6 +177,10 @@ export interface Message {
   // (CoderPane/CoderMessageList) and streams it live via reasoning_delta
   // frames. MessageBubble reads whichever of the two is present.
   reasoning_text?: string | null;
+  // v2.8-compare: compare group id. Set when the message is part of a
+  // multi-model compare response. All assistant messages in the same compare
+  // group share this id, keyed to the user message that triggered the compare.
+  compare_group_id?: string;
   // v1.11: anchored rolling compaction fields. Optional on the wire so that
   // older API responses (or test fixtures) parse without explicit nulls.
   //   summary       — true on the assistant row that holds the active
@@ -513,8 +522,8 @@ export interface WorkspaceState {
 
 export type WsFrame =
   | { type: 'snapshot'; messages: Message[] }
-  | { type: 'message_started'; message_id: string; chat_id?: string; role: MessageRole }
+  | { type: 'message_started'; message_id: string; chat_id?: string; role: MessageRole; compare_group_id?: string }
-  | { type: 'delta'; message_id: string; chat_id?: string; content: string }
+  | { type: 'delta'; message_id: string; chat_id?: string; content: string; compare_group_id?: string }
   | { type: 'tool_call'; message_id: string; chat_id?: string; tool_call: ToolCall }
   | {
       type: 'tool_result';
@@ -524,6 +533,7 @@ export type WsFrame =
       output: unknown;
       truncated: boolean;
       error?: string;
+      diff?: string;
     }
   | {
       type: 'message_complete';
@@ -532,6 +542,8 @@ export type WsFrame =
       tokens_used?: number | null;
       ctx_used?: number | null;
       ctx_max?: number | null;
+      cache_tokens?: number | null;
+      reasoning_tokens?: number | null;
       started_at?: string | null;
       finished_at?: string | null;
       // model-attribution: the model that produced this assistant message.
@@ -545,6 +557,7 @@ export type WsFrame =
       // 'cancelled' on a user Stop / stall and 'failed' on a thrown error so the
       // reducer renders a muted "Stopped" / failed state — no new frame type.
       status?: 'complete' | 'cancelled' | 'failed';
+      compare_group_id?: string;
     }
   // v1.12.2: live throughput frame, published mid-stream every ~500ms with
   // the latest token + ctx counts so ChatThroughput can render tok/s and
@@ -559,6 +572,14 @@ export type WsFrame =
     }
   | { type: 'messages_deleted'; message_ids: string[]; chat_id?: string     }
   | { type: 'chat_renamed'; chat_id: string; name: string }
+  | {
+      type: 'agent_snapshot';
+      chat_id: string;
+      agent?: string | null;
+      model: string;
+      mode?: string | null;
+      turn_number: number;
+    }
   // v1.11: published by services/compaction.ts after the new anchored
   // summary row lands. Carries the new summary row id for diagnostics; the
   // session-stream handler ignores the id and re-fetches the full message
@@ -566,7 +587,7 @@ export type WsFrame =
   | { type: 'compacted'; session_id: string; chat_id: string; summary_message_id: string }
   // v1.8.2: `reason` discriminates structured failures (the UI prefers it
   // over `error` text when present).
-  | { type: 'error'; message_id?: string; chat_id?: string; error: string; reason?: ErrorReason }
+  | { type: 'error'; message_id?: string; chat_id?: string; error: string; reason?: ErrorReason; compare_group_id?: string }
   // agent-status-normalize (#10): BooCoder publishes a normalized per-(chat,agent)
   // lifecycle status for external coding agents on the per-session channel. The
   // CoderPane tracks the latest status per (chat_id, agent) and resets on chat
@@ -602,6 +623,31 @@ export type WsFrame =
       run_status?: 'running' | 'completed' | 'failed' | 'cancelled';
       report?: string;
     }
+  // tool trace frames: per-tool-call lifecycle tracking
+  | {
+      type: 'tool_trace_start';
+      trace_id: string;
+      message_id: string;
+      chat_id: string;
+      tool_name: string;
+      tool_input: Record<string, unknown>;
+      started_at: string;
+    }
+  | {
+      type: 'tool_trace_finish';
+      trace_id: string;
+      message_id: string;
+      chat_id: string;
+      tool_name: string;
+      tool_output?: string | null;
+      latency_ms?: number;
+      tokens_used?: number | null;
+      cache_tokens?: number | null;
+      reasoning_tokens?: number | null;
+      error?: string;
+      outcome?: string;
+      finished_at: string;
+    }
   // arena frames: battle lifecycle + per-contestant streaming
   | {
       type: 'battle_started';
@@ -628,8 +674,66 @@ export type WsFrame =
       winner_contestant_id?: string | null;
       analysis_ready?: boolean;
       cross_exam_id?: string;
+    }
+  // streaming v2: channel-delta frames. Each carries a monotonic seq for
+  // out-of-order buffering and a channel discriminator; per-channel payloads
+  // map to the equivalent legacy frame types after reordering.
+  | {
+      type: 'channel_delta';
+      seq: number;
+      channel: 'text' | 'tool_call' | 'tool_result' | 'status' | 'error';
+      message_id?: string;
+      chat_id?: string;
+      content?: string;
+      compare_group_id?: string;
+      tool_call?: ToolCall;
+      tool_message_id?: string;
+      tool_call_id?: string;
+      output?: unknown;
+      truncated?: boolean;
+      diff?: string;
+      error?: string;
+      reason?: string;
+      status?: 'running' | 'complete' | 'cancelled' | 'failed';
+      tokens_used?: number | null;
+      ctx_used?: number | null;
+      ctx_max?: number | null;
+      cache_tokens?: number | null;
+      reasoning_tokens?: number | null;
+      started_at?: string | null;
+      finished_at?: string | null;
+      model?: string | null;
+      metadata?: MessageMetadata | null;
     };
 
+// tool traces: per-tool-call record returned by GET /api/chats/:id/traces.
+export interface ToolTrace {
+  id: string;
+  session_id: string;
+  chat_id: string;
+  message_id: string | null;
+  turn_number: number;
+  tool_name: string;
+  tool_input: Record<string, unknown>;
+  tool_output: string | null;
+  started_at: string;
+  finished_at: string | null;
+  latency_ms: number | null;
+  tokens_used: number | null;
+  cache_tokens: number | null;
+  reasoning_tokens: number | null;
+  error: string | null;
+  outcome: string | null;
+  created_at: string;
+}
+
+export interface ToolTraceResponse {
+  data: ToolTrace[];
+  total: number;
+  limit: number;
+  offset: number;
+}
+
 // token-analyzer-ui: aggregate token/cost analytics types.
 export interface AnalyticsSummary {
   total_input_tokens: number;
@@ -658,3 +762,21 @@ export interface TokenBreakdownAgg {
   category: string;
   total_tokens: number;
 }
+
+// ── Memory browser types ────────────────────────────────────────────
+export interface MemoryEntry {
+  id: string;
+  topic: string;
+  title: string;
+  content: string;
+  tags: string[];
+}
+
+export interface DailyMemoryEntry extends MemoryEntry {
+  date: string;
+}
+
+export interface DreamEntry {
+  date: string;
+  content: string;
+}

apps/web/src/components/CacheShapeBadge.tsx

@@ -0,0 +1,38 @@
+// vDeepSeek: cache shape telemetry badge. Displays cache token count with
+// a colored hit-rate bar in the trace viewer. Color thresholds are relative
+// to output tokens (tokens_used) since the trace doesn't carry prompt miss
+// tokens separately: green > 50%, yellow > 10%, red ≤ 10%.
+
+export interface CacheShapeBadgeProps {
+  cacheTokens: number | null | undefined;
+  totalTokens: number | null | undefined;
+}
+
+function hitRate(cache: number, total: number): number {
+  if (cache <= 0 || total <= 0) return 0;
+  return cache / (cache + total);
+}
+
+function barColor(rate: number): string {
+  if (rate > 0.5) return 'bg-green-500';
+  if (rate > 0.1) return 'bg-yellow-500';
+  return 'bg-red-500';
+}
+
+export function CacheShapeBadge({ cacheTokens, totalTokens }: CacheShapeBadgeProps) {
+  if (cacheTokens == null || cacheTokens <= 0) return null;
+
+  const rate = hitRate(cacheTokens, totalTokens ?? 0);
+  const pct = Math.round(rate * 100);
+  const color = barColor(rate);
+
+  return (
+    <span className="shrink-0 inline-flex items-center gap-1 font-mono tabular-nums text-[10px] text-muted-foreground/60" title={`cache hit rate ${pct}%`}>
+      <span className={`inline-block w-1.5 h-3 rounded-sm ${color}`} />
+      <span>{cacheTokens}c</span>
+      {totalTokens != null && totalTokens > 0 && (
+        <span className="text-muted-foreground/40">{pct}%</span>
+      )}
+    </span>
+  );
+}

apps/web/src/components/DiffSnippet.tsx

@@ -0,0 +1,88 @@
+import { useMemo, useState } from 'react';
+import { ChevronDown, ChevronRight, FileCode } from 'lucide-react';
+
+interface Props {
+  diff: string;
+}
+
+const INITIAL_LINES = 10;
+
+export function DiffSnippet({ diff }: Props) {
+  const [expanded, setExpanded] = useState(false);
+
+  const lines = useMemo(() => diff.split('\n'), [diff]);
+  const totalLines = lines.length;
+
+  // Find the first and last content lines (skip leading ---/+++ headers)
+  const firstContentIdx = lines.findIndex(
+    (l) => l.startsWith('+') || l.startsWith('-') || l.startsWith(' '),
+  );
+
+  // Count content lines that are either +, -, or context lines
+  const contentLineCount = lines.filter(
+    (l) => l.startsWith('+') || l.startsWith('-') || l.startsWith(' '),
+  ).length;
+
+  // Show first N content lines, plus header lines
+  const displayLines = useMemo(() => {
+    const sliceEnd = expanded ? lines.length : Math.min(firstContentIdx + INITIAL_LINES + contentLineCount, lines.length);
+    return lines.slice(0, sliceEnd);
+  }, [lines, expanded, firstContentIdx, contentLineCount]);
+
+  const hasMore = totalLines > displayLines.length;
+
+  if (totalLines === 0) return null;
+
+  return (
+    <div className="mt-1 rounded border border-border/40 bg-muted/20 overflow-hidden">
+      <button
+        type="button"
+        onClick={() => setExpanded((v) => !v)}
+        className="flex items-center gap-1.5 w-full px-2 py-1 text-left hover:bg-muted/30 text-[10px] font-mono text-muted-foreground"
+      >
+        <FileCode className="size-3 shrink-0" />
+        <span className="font-medium">diff</span>
+        <span className="text-muted-foreground/60">
+          — {contentLineCount} line{contentLineCount === 1 ? '' : 's'} changed
+        </span>
+        <span className="ml-auto shrink-0">
+          {expanded ? <ChevronDown className="size-3" /> : <ChevronRight className="size-3" />}
+        </span>
+      </button>
+      <div className="px-0 pb-0.5">
+        {displayLines.map((line, i) => {
+          // Determine color class based on line prefix
+          let colorClass = 'text-muted-foreground/60';
+          if (line.startsWith('+')) colorClass = 'text-emerald-600 dark:text-emerald-400';
+          else if (line.startsWith('-')) colorClass = 'text-red-500 dark:text-red-400';
+          else if (line.startsWith('@@')) colorClass = 'text-muted-foreground';
+          else if (line.startsWith('---') || line.startsWith('+++')) colorClass = 'text-muted-foreground/50';
+
+          return (
+            <div
+              key={i}
+              className={`leading-[1.3] px-2 text-[10px] font-mono whitespace-pre ${colorClass} ${
+                line.startsWith('+')
+                  ? 'bg-emerald-500/5'
+                  : line.startsWith('-')
+                    ? 'bg-red-500/5'
+                    : ''
+              }`}
+            >
+              {line}
+            </div>
+          );
+        })}
+        {hasMore && !expanded && (
+          <button
+            type="button"
+            onClick={() => setExpanded(true)}
+            className="w-full text-left px-2 py-0.5 text-[10px] font-mono text-muted-foreground/60 hover:text-muted-foreground hover:bg-muted/30"
+          >
+            Show {totalLines - displayLines.length} more lines…
+          </button>
+        )}
+      </div>
+    </div>
+  );
+}

apps/web/src/components/MessageList.tsx

@@ -1,10 +1,14 @@
-import { useCallback, useEffect, useMemo, useRef } from 'react';
+import { useCallback, useEffect, useMemo, useRef, useState } from 'react';
+import { motion } from 'framer-motion';
+import { Virtuoso, type VirtuosoHandle } from 'react-virtuoso';
+import { Pin } from 'lucide-react';
 import type { Chat, Message } from '@/api/types';
 import { MessageBubble } from './MessageBubble';
 import { ToolCallGroup } from './ToolCallGroup';
 import { ToolCallLine, type ToolRun } from './ToolCallLine';
 import { AskUserInputCard } from './AskUserInputCard';
 import { RequestReadAccessCard } from './RequestReadAccessCard';
+import { MessageListErrorBoundary } from './MessageListErrorBoundary';
 
 interface Props {
   messages: Message[];
@@ -142,27 +146,63 @@ function stampCapHits(items: RenderItem[]): RenderItem[] {
   });
 }
 
-const SCROLL_THRESHOLD_PX = 150;
-
 export function MessageList({ messages, sessionChats }: Props) {
-  const endRef = useRef<HTMLDivElement>(null);
+  const virtuosoRef = useRef<VirtuosoHandle>(null);
-  const scrollContainerRef = useRef<HTMLDivElement>(null);
   const isNearBottomRef = useRef(true);
+  const renderedKeysRef = useRef(new Set<string>());
+  const prefersReducedMotionRef = useRef(false);
+  const [animateEnabled, setAnimateEnabled] = useState(true);
+
+  const [pinMessageId, setPinMessageId] = useState<string | null>(() => {
+    if (typeof window !== 'undefined') {
+      const hash = window.location.hash;
+      if (hash.startsWith('#pin=')) return hash.slice(5);
+    }
+    return null;
+  });
 
   const renderItems = useMemo(() => stampCapHits(group(flatten(messages))), [messages]);
 
-  const handleScroll = useCallback(() => {
+  const pinIndex = useMemo(() => {
-    const el = scrollContainerRef.current;
+    if (!pinMessageId) return -1;
-    if (!el) return;
+    return renderItems.findIndex(
-    isNearBottomRef.current =
+      (item) => item.kind === 'message' && item.message.id === pinMessageId,
-      el.scrollHeight - el.scrollTop - el.clientHeight < SCROLL_THRESHOLD_PX;
+    );
+  }, [pinMessageId, renderItems]);
+
+  useEffect(() => {
+    const mq = window.matchMedia('(prefers-reduced-motion: reduce)');
+    prefersReducedMotionRef.current = mq.matches;
+    const handler = (e: MediaQueryListEvent) => {
+      prefersReducedMotionRef.current = e.matches;
+    };
+    mq.addEventListener('change', handler);
+    return () => mq.removeEventListener('change', handler);
   }, []);
 
   useEffect(() => {
-    if (isNearBottomRef.current) {
+    const handler = () => {
-      endRef.current?.scrollIntoView({ block: 'end' });
+      const hash = window.location.hash;
+      if (hash.startsWith('#pin=')) {
+        setPinMessageId(hash.slice(5));
+      } else {
+        setPinMessageId(null);
       }
-  }, [messages]);
+    };
+    window.addEventListener('hashchange', handler);
+    return () => window.removeEventListener('hashchange', handler);
+  }, []);
+
+  const atBottomStateChange = useCallback((atBottom: boolean) => {
+    isNearBottomRef.current = atBottom;
+    setAnimateEnabled(atBottom);
+  }, []);
+
+  const scrollToPin = useCallback(() => {
+    if (pinIndex >= 0 && virtuosoRef.current) {
+      virtuosoRef.current.scrollToIndex({ index: pinIndex, align: 'center' });
+    }
+  }, [pinIndex]);
 
   if (messages.length === 0) {
     return (
@@ -173,46 +213,78 @@ export function MessageList({ messages, sessionChats }: Props) {
   }
 
   return (
-    <div className="flex-1 overflow-y-auto" ref={scrollContainerRef} onScroll={handleScroll}>
+    <MessageListErrorBoundary>
-      <div className="max-w-[1000px] mx-auto w-full px-6 py-4 space-y-4">
+    <div className="flex-1 flex flex-col">
-        {renderItems.map((item) => {
+      {pinMessageId && pinIndex >= 0 && (
-          if (item.kind === 'message') {
+        <div className="shrink-0 flex items-center gap-2 px-4 py-1.5 bg-primary/10 border-b border-primary/20 text-xs text-primary">
+          <Pin className="size-3" />
+          <span>Pinned message</span>
+          <button
+            type="button"
+            onClick={scrollToPin}
+            className="ml-auto underline hover:no-underline"
+          >
+            Jump to pinned
+          </button>
+        </div>
+      )}
+      <Virtuoso
+        ref={virtuosoRef}
+        className="flex-1"
+        data={renderItems}
+        followOutput="auto"
+        overscan={5}
+        atBottomStateChange={atBottomStateChange}
+        itemContent={(index, item) => {
+          const key = item.kind === 'message' ? `msg-${item.message.id}` : item.key;
+          const isNew = !renderedKeysRef.current.has(key);
+          if (isNew) renderedKeysRef.current.add(key);
+
+          const reducedMotion = prefersReducedMotionRef.current;
+          const delay = isNew && !reducedMotion ? Math.min(index * 0.04, 0.5) : 0;
+          const shouldAnimate = isNew && animateEnabled;
+
           return (
+            <div
+              className="max-w-[1000px] mx-auto w-full px-6 py-2"
+              id={item.kind === 'message' ? `msg-${item.message.id}` : undefined}
+            >
+              <motion.div
+                initial={shouldAnimate ? { opacity: 0, y: 8 } : false}
+                animate={{ opacity: 1, y: 0 }}
+                transition={delay > 0 ? { duration: 0.2, delay } : { duration: 0 }}
+              >
+                {item.kind === 'message' ? (
                   <MessageBubble
-                key={item.message.id}
                     message={item.message}
                     sessionChats={sessionChats}
                     capHitInfo={item.capHitInfo}
                   />
-            );
+                ) : item.kind === 'tool_run' ? (
-          }
+                  item.run.call.name === 'ask_user_input' ? (
-          if (item.kind === 'tool_run') {
-            if (item.run.call.name === 'ask_user_input') {
-              return (
                     <AskUserInputCard
-                  key={item.key}
                       toolCall={item.run.call}
                       toolResult={item.run.result}
                       chatId={item.chatId}
                     />
-              );
+                  ) : item.run.call.name === 'request_read_access' ? (
-            }
-            if (item.run.call.name === 'request_read_access') {
-              return (
                     <RequestReadAccessCard
-                  key={item.key}
                       toolCall={item.run.call}
                       toolResult={item.run.result}
                       chatId={item.chatId}
                     />
+                  ) : (
+                    <ToolCallLine run={item.run} />
+                  )
+                ) : (
+                  <ToolCallGroup runs={item.runs} />
+                )}
+              </motion.div>
+            </div>
           );
-            }
+        }}
-            return <ToolCallLine key={item.key} run={item.run} />;
+      />
-          }
-          return <ToolCallGroup key={item.key} runs={item.runs} />;
-        })}
-        <div ref={endRef} />
-      </div>
     </div>
+    </MessageListErrorBoundary>
   );
 }

apps/web/src/components/SessionTimeline.tsx

@@ -0,0 +1,188 @@
+import { useMemo } from 'react';
+import { Clock, Cpu, Hash, Layers, RefreshCw, X } from 'lucide-react';
+import { Button } from '@/components/ui/button';
+import { cn } from '@/lib/utils';
+import type { Message } from '@/api/types';
+
+interface TurnEntry {
+  message: Message;
+  turnNumber: number;
+  elapsed: string;
+  toolCallCount: number;
+}
+
+interface Props {
+  messages: Message[];
+  chatId: string;
+  onClose: () => void;
+  onScrollToMessage: (messageId: string) => void;
+}
+
+function formatElapsed(startedAt: string | null, finishedAt: string | null): string {
+  if (!startedAt || !finishedAt) return '—';
+  const start = new Date(startedAt).getTime();
+  const end = new Date(finishedAt).getTime();
+  if (Number.isNaN(start) || Number.isNaN(end)) return '—';
+  const ms = end - start;
+  if (ms < 0) return '—';
+  if (ms < 1000) return `${ms}ms`;
+  if (ms < 60_000) return `${Math.round(ms / 1000)}s`;
+  const mins = Math.floor(ms / 60_000);
+  const secs = Math.round((ms % 60_000) / 1000);
+  return `${mins}m ${secs}s`;
+}
+
+/**
+ * SessionTimeline — vertical timeline of assistant turns in a chat.
+ *
+ * Renders a side-panel overlay with each turn's model, tokens, duration,
+ * and tool-call count. Clicking a turn scrolls the main chat to that
+ * message. The latest turn shows a "Scroll to latest" restore button.
+ */
+export function SessionTimeline({ messages, onClose, onScrollToMessage }: Props) {
+  const turns = useMemo<TurnEntry[]>(() => {
+    const assistantMsgs = messages.filter(
+      (m) => m.role === 'assistant' && m.status === 'complete',
+    );
+    return assistantMsgs.map((message, i) => ({
+      message,
+      turnNumber: i + 1,
+      elapsed: formatElapsed(message.started_at, message.finished_at),
+      toolCallCount: message.tool_calls?.length ?? 0,
+    }));
+  }, [messages]);
+
+  const latestTurnId = turns.length > 0 ? turns[turns.length - 1]!.message.id : null;
+
+  return (
+    <div className="absolute inset-y-0 right-0 w-80 z-20 bg-background border-l border-border shadow-xl flex flex-col overflow-hidden">
+      {/* Header */}
+      <div className="flex items-center justify-between px-3 py-2.5 border-b border-border shrink-0">
+        <h3 className="text-sm font-semibold">Session Timeline</h3>
+        <Button variant="ghost" size="icon-xs" onClick={onClose} aria-label="Close timeline">
+          <X size={14} />
+        </Button>
+      </div>
+
+      {/* Timeline entries */}
+      <div className="flex-1 overflow-y-auto px-3 py-3">
+        {turns.length === 0 ? (
+          <div className="text-xs text-muted-foreground text-center py-8">
+            No assistant turns yet.
+          </div>
+        ) : (
+          <div className="relative">
+            {turns.map((turn, i) => {
+              const isLatest = turn.message.id === latestTurnId;
+              return (
+                <div key={turn.message.id} className="relative flex gap-3 pb-4 last:pb-0">
+                  {/* Vertical connector line */}
+                  {i < turns.length - 1 && (
+                    <div className="absolute left-[11px] top-5 bottom-0 w-px bg-border" />
+                  )}
+
+                  {/* Timeline dot button */}
+                  <button
+                    type="button"
+                    onClick={() => onScrollToMessage(turn.message.id)}
+                    className="relative flex-shrink-0 mt-1 cursor-pointer focus:outline-none focus-visible:ring-2 focus-visible:ring-ring rounded-full"
+                    aria-label={`Scroll to turn ${turn.turnNumber}`}
+                  >
+                    <div
+                      className={cn(
+                        'size-[22px] rounded-full border-2 flex items-center justify-center',
+                        isLatest
+                          ? 'border-primary bg-primary/10'
+                          : 'border-muted-foreground/30 bg-background',
+                      )}
+                    >
+                      <div
+                        className={cn(
+                          'size-2 rounded-full',
+                          isLatest ? 'bg-primary' : 'bg-muted-foreground/50',
+                        )}
+                      />
+                    </div>
+                  </button>
+
+                  {/* Content card */}
+                  <div className="flex-1 min-w-0">
+                    <div
+                      className="rounded-lg border border-border bg-card p-2.5 cursor-pointer hover:bg-muted/40 transition-colors"
+                      onClick={() => onScrollToMessage(turn.message.id)}
+                    >
+                      {/* Turn number + latest badge */}
+                      <div className="flex items-center justify-between mb-1.5">
+                        <span className="text-xs font-semibold text-foreground">
+                          Turn {turn.turnNumber}
+                        </span>
+                        {isLatest && (
+                          <span className="text-[10px] font-medium text-primary bg-primary/10 px-1.5 py-0.5 rounded-full leading-none">
+                            Latest
+                          </span>
+                        )}
+                      </div>
+
+                      {/* Model name */}
+                      <div className="flex items-center gap-1.5 text-xs text-muted-foreground mb-1.5">
+                        <Cpu size={11} className="shrink-0" />
+                        <span className="truncate">{turn.message.model ?? 'Unknown model'}</span>
+                      </div>
+
+                      {/* Token count with breakdown */}
+                      {turn.message.tokens_used != null && (
+                        <div className="flex items-center gap-1.5 text-xs text-muted-foreground mb-1 flex-wrap">
+                          <Hash size={11} className="shrink-0" />
+                          <span>{turn.message.tokens_used.toLocaleString()} total</span>
+                          {turn.message.cache_tokens != null && turn.message.cache_tokens > 0 && (
+                            <span className="text-blue-500 dark:text-blue-400">
+                              ({turn.message.cache_tokens.toLocaleString()} cache)
+                            </span>
+                          )}
+                          {turn.message.reasoning_tokens != null && turn.message.reasoning_tokens > 0 && (
+                            <span className="text-amber-500 dark:text-amber-400">
+                              ({turn.message.reasoning_tokens.toLocaleString()} reasoning)
+                            </span>
+                          )}
+                        </div>
+                      )}
+
+                      {/* Duration + tool calls */}
+                      <div className="flex items-center gap-3 text-xs text-muted-foreground">
+                        <span className="inline-flex items-center gap-1">
+                          <Clock size={11} />
+                          {turn.elapsed}
+                        </span>
+                        {turn.toolCallCount > 0 && (
+                          <span className="inline-flex items-center gap-1">
+                            <Layers size={11} />
+                            {turn.toolCallCount} tool call{turn.toolCallCount !== 1 ? 's' : ''}
+                          </span>
+                        )}
+                      </div>
+                    </div>
+
+                    {/* Restore button for latest turn */}
+                    {isLatest && (
+                      <button
+                        type="button"
+                        onClick={(e) => {
+                          e.stopPropagation();
+                          onScrollToMessage(turn.message.id);
+                        }}
+                        className="mt-1.5 w-full inline-flex items-center justify-center gap-1 text-[11px] font-medium text-primary hover:text-primary/80 transition-colors py-1 rounded-md hover:bg-primary/5"
+                      >
+                        <RefreshCw size={11} />
+                        Scroll to latest
+                      </button>
+                    )}
+                  </div>
+                </div>
+              );
+            })}
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}

apps/web/src/components/ToolCallLine.tsx

@@ -1,7 +1,9 @@
 import { useState } from 'react';
-import { Check, ChevronRight, Loader2, X } from 'lucide-react';
+import { Check, ChevronRight, Loader2, ShieldAlert, X } from 'lucide-react';
 import type { ToolCall, ToolResult } from '@/api/types';
 import { linkifyPaths } from '@/lib/linkify-paths';
+import { DiffSnippet } from './DiffSnippet';
+import { McpPermissionDialog } from './McpPermissionDialog';
 
 // v1.8.2: cap on the inline arg-summary length. Expanded view shows full
 // args + full result, so this is purely a single-line render budget.
@@ -105,14 +107,18 @@ interface Props {
   // When rendered inside a ToolCallGroup the line is already nested under a
   // shared header, so the leading arrow is dropped to avoid double indent.
   insideGroup?: boolean;
+  chatId?: string;
 }
 
-export function ToolCallLine({ run, insideGroup }: Props) {
+export function ToolCallLine({ run, insideGroup, chatId }: Props) {
   const [open, setOpen] = useState(false);
+  const [approveOpen, setApproveOpen] = useState(false);
   const status = runStatus(run);
   const args = run.call.args ?? {};
   const summary = formatToolArgs(run.call.name, args);
 
+  const needsApproval = run.result?.error?.startsWith('requires approval:') === true;
+
   return (
     <div className="text-xs">
       <button
@@ -129,7 +135,7 @@ export function ToolCallLine({ run, insideGroup }: Props) {
           />
         )}
         <ChevronRight
-          className={`size-3 text-muted-foreground/60 shrink-0 transition-transform ${open ? 'rotate-90' : ''}`}
+          className={`size-3 text-muted-foreground/60 shrink-0 motion-reduce:transition-none transition-transform ${open ? 'rotate-90' : ''}`}
         />
         <span className="font-mono text-foreground/90 shrink-0">{run.call.name}</span>
         {summary && (
@@ -158,7 +164,27 @@ export function ToolCallLine({ run, insideGroup }: Props) {
           {run.result && (
             <pre className="text-[11px] font-mono whitespace-pre-wrap bg-muted/30 rounded px-2 py-1 max-h-72 overflow-y-auto">
               {run.result.error ? (
+                needsApproval ? (
+                  <span className="flex flex-col gap-2">
+                    <span className="text-amber-600 dark:text-amber-400">
+                      This tool requires your approval
+                    </span>
+                    {chatId && (
+                      <span>
+                        <button
+                          type="button"
+                          onClick={() => setApproveOpen(true)}
+                          className="inline-flex items-center gap-1 rounded bg-amber-500/10 px-2 py-1 text-xs font-medium text-amber-600 hover:bg-amber-500/20 dark:text-amber-400"
+                        >
+                          <ShieldAlert className="size-3" />
+                          Approve
+                        </button>
+                      </span>
+                    )}
+                  </span>
+                ) : (
                   <span className="text-destructive">{run.result.error}</span>
+                )
               ) : (
                 linkifyPaths(
                   typeof run.result.output === 'string'
@@ -171,6 +197,17 @@ export function ToolCallLine({ run, insideGroup }: Props) {
               )}
             </pre>
           )}
+          {needsApproval && chatId && (
+            <McpPermissionDialog
+              toolCallId={run.call.id}
+              toolName={run.call.name}
+              toolArgs={run.call.args ?? {}}
+              chatId={chatId}
+              open={approveOpen}
+              onClose={() => setApproveOpen(false)}
+            />
+          )}
+          {run.result?.diff && <DiffSnippet diff={run.result.diff} />}
         </div>
       )}
     </div>

apps/web/src/components/TraceViewer.tsx

@@ -0,0 +1,248 @@
+import { useCallback, useEffect, useMemo, useState } from 'react';
+import { ChevronDown, ChevronRight, AlertCircle } from 'lucide-react';
+import { api } from '@/api/client';
+import type { ToolTrace } from '@/api/types';
+import { CacheShapeBadge } from '@/components/CacheShapeBadge';
+
+interface Props {
+  chatId: string;
+}
+
+// Max latency used as the 100% reference for the bar visualization
+const MAX_LATENCY_REF = 30_000; // 30s
+
+function latencyBarWidth(latencyMs: number | null): number {
+  if (latencyMs == null) return 0;
+  return Math.min(latencyMs / MAX_LATENCY_REF, 1);
+}
+
+function TraceRow({ trace }: { trace: ToolTrace }) {
+  const [expanded, setExpanded] = useState(false);
+  const isError = trace.outcome !== null && trace.outcome !== 'success';
+  const barWidth = latencyBarWidth(trace.latency_ms);
+  const latencyLabel =
+    trace.latency_ms != null
+      ? trace.latency_ms >= 1000
+        ? `${(trace.latency_ms / 1000).toFixed(1)}s`
+        : `${trace.latency_ms}ms`
+      : null;
+
+  return (
+    <div className="border-b border-border/40 last:border-0">
+      <button
+        type="button"
+        onClick={() => setExpanded((v) => !v)}
+        className="flex items-center gap-2 w-full text-left px-2 py-1.5 hover:bg-muted/40 text-[11px]"
+      >
+        <span className="shrink-0 text-muted-foreground">
+          {expanded ? <ChevronDown size={10} /> : <ChevronRight size={10} />}
+        </span>
+        <span className="font-medium truncate min-w-0">
+          {trace.tool_name}
+        </span>
+        {isError && (
+          <span className="shrink-0 text-destructive" title={trace.error ?? 'error'}>
+            <AlertCircle size={10} />
+          </span>
+        )}
+        <span className="shrink-0 text-muted-foreground font-mono tabular-nums min-w-[3rem] text-right">
+          {latencyLabel ?? '—'}
+        </span>
+        <span className="flex-1 h-1.5 bg-muted rounded-full overflow-hidden min-w-[24px] max-w-[60px]">
+          <span
+            className="block h-full rounded-full bg-primary/30 transition-all"
+            style={{ width: `${barWidth * 100}%` }}
+          />
+        </span>
+        {trace.tokens_used != null && trace.tokens_used > 0 && (
+          <span className="shrink-0 text-muted-foreground font-mono tabular-nums">
+            {trace.tokens_used}t
+          </span>
+        )}
+        <CacheShapeBadge cacheTokens={trace.cache_tokens} totalTokens={trace.tokens_used} />
+        {trace.reasoning_tokens != null && trace.reasoning_tokens > 0 && (
+          <span className="shrink-0 text-muted-foreground/60 font-mono tabular-nums text-[10px]">
+            r{trace.reasoning_tokens}
+          </span>
+        )}
+      </button>
+      {expanded && (
+        <div className="px-3 pb-2 space-y-1.5 text-[11px] border-t border-border/40 pt-1.5">
+          <div>
+            <span className="text-muted-foreground font-medium">Input</span>
+            <pre className="mt-0.5 font-mono text-[10px] leading-relaxed text-muted-foreground bg-muted/30 rounded p-1.5 overflow-x-auto max-h-32 overflow-y-auto whitespace-pre-wrap break-all">
+              {JSON.stringify(trace.tool_input, null, 1)}
+            </pre>
+          </div>
+          {trace.tool_output != null && (
+            <div>
+              <span className="text-muted-foreground font-medium">Output</span>
+              <pre className="mt-0.5 font-mono text-[10px] leading-relaxed text-muted-foreground bg-muted/30 rounded p-1.5 overflow-x-auto max-h-32 overflow-y-auto whitespace-pre-wrap break-all">
+                {trace.tool_output.length > 2000
+                  ? `${trace.tool_output.slice(0, 2000)}…`
+                  : trace.tool_output}
+              </pre>
+            </div>
+          )}
+          {trace.error != null && (
+            <div className="text-destructive text-[10px] font-mono leading-relaxed bg-destructive/10 rounded p-1.5">
+              {trace.error}
+            </div>
+          )}
+        </div>
+      )}
+    </div>
+  );
+}
+
+function TraceGroup({ toolName, traces }: { toolName: string; traces: ToolTrace[] }) {
+  const [collapsed, setCollapsed] = useState(false);
+  const totalLatency = traces.reduce((sum, t) => sum + (t.latency_ms ?? 0), 0);
+  const totalTokens = traces.reduce((sum, t) => sum + (t.tokens_used ?? 0), 0);
+  const errorCount = traces.filter(
+    (t) => t.outcome !== null && t.outcome !== 'success',
+  ).length;
+
+  return (
+    <div>
+      <button
+        type="button"
+        onClick={() => setCollapsed((v) => !v)}
+        className="flex items-center gap-1.5 w-full text-left px-2 py-1 text-[11px] font-medium text-muted-foreground hover:bg-muted/30 sticky top-0 bg-background"
+      >
+        {collapsed ? <ChevronRight size={10} /> : <ChevronDown size={10} />}
+        <span>{toolName}</span>
+        <span className="text-muted-foreground/60 font-mono tabular-nums">
+          ×{traces.length}
+        </span>
+        {totalTokens > 0 && (
+          <span className="text-muted-foreground/60 font-mono tabular-nums text-[10px]">
+            {totalTokens}t
+          </span>
+        )}
+        {totalLatency > 0 && (
+          <span className="text-muted-foreground/60 font-mono tabular-nums text-[10px]">
+            {totalLatency >= 1000
+              ? `${(totalLatency / 1000).toFixed(1)}s`
+              : `${totalLatency}ms`}
+          </span>
+        )}
+        {errorCount > 0 && (
+          <span className="ml-auto text-destructive text-[10px] font-medium">
+            {errorCount} error{errorCount > 1 ? 's' : ''}
+          </span>
+        )}
+      </button>
+      {!collapsed && traces.map((trace) => (
+        <TraceRow key={trace.id} trace={trace} />
+      ))}
+    </div>
+  );
+}
+
+export function TraceViewer({ chatId }: Props) {
+  const [open, setOpen] = useState(false);
+  const [traces, setTraces] = useState<ToolTrace[]>([]);
+  const [loading, setLoading] = useState(false);
+  const [error, setError] = useState<string | null>(null);
+
+  const fetchTraces = useCallback(async () => {
+    setLoading(true);
+    setError(null);
+    try {
+      const res = await api.chats.getTraces(chatId);
+      setTraces(res.data);
+    } catch (err) {
+      setError(err instanceof Error ? err.message : 'failed to load traces');
+    } finally {
+      setLoading(false);
+    }
+  }, [chatId]);
+
+  useEffect(() => {
+    if (open) {
+      void fetchTraces();
+    }
+  }, [open, fetchTraces]);
+
+  const groups = useMemo(() => {
+    const map = new Map<string, ToolTrace[]>();
+    for (const t of traces) {
+      const existing = map.get(t.tool_name);
+      if (existing) {
+        existing.push(t);
+      } else {
+        map.set(t.tool_name, [t]);
+      }
+    }
+    return map;
+  }, [traces]);
+
+  const totalCount = traces.length;
+  const errorCount = traces.filter(
+    (t) => t.outcome !== null && t.outcome !== 'success',
+  ).length;
+
+  return (
+    <div className="border-t">
+      <button
+        type="button"
+        onClick={() => setOpen((v) => !v)}
+        className="flex items-center gap-1.5 w-full px-3 py-1.5 text-[11px] font-medium text-muted-foreground hover:bg-muted/20"
+      >
+        {open ? <ChevronDown size={12} /> : <ChevronRight size={12} />}
+        <span>Tool traces</span>
+        {totalCount > 0 && (
+          <span className="font-mono tabular-nums text-muted-foreground/60">
+            {totalCount}
+          </span>
+        )}
+        {errorCount > 0 && (
+          <span className="text-destructive ml-auto text-[10px] font-medium">
+            {errorCount} error{errorCount > 1 ? 's' : ''}
+          </span>
+        )}
+        {loading && (
+          <span className="ml-auto inline-block w-1.5 h-3 align-baseline bg-muted-foreground/60 animate-pulse" />
+        )}
+      </button>
+      {open && (
+        <div className="max-h-80 overflow-y-auto border-t border-border/40">
+          {loading && traces.length === 0 && (
+            <div className="px-3 py-4 text-[11px] text-muted-foreground text-center">
+              Loading traces…
+            </div>
+          )}
+          {error && (
+            <div className="px-3 py-2 text-[11px] text-destructive">
+              {error}
+              <button
+                type="button"
+                onClick={() => void fetchTraces()}
+                className="ml-2 underline hover:no-underline"
+              >
+                retry
+              </button>
+            </div>
+          )}
+          {!loading && !error && traces.length === 0 && (
+            <div className="px-3 py-4 text-[11px] text-muted-foreground text-center">
+              No tool traces yet.
+            </div>
+          )}
+          {traces.length > 0 && (
+            <div className="divide-y divide-border/40">
+              {Array.from(groups.entries()).map(([toolName, groupTraces]) => (
+                <TraceGroup
+                  key={toolName}
+                  toolName={toolName}
+                  traces={groupTraces}
+                />
+              ))}
+            </div>
+          )}
+        </div>
+      )}
+    </div>
+  );
+}

apps/web/src/components/panes/ChatPane.tsx

@@ -1,11 +1,13 @@
 import { useCallback, useEffect, useRef, useState } from 'react';
-import { Pencil, Send, X } from 'lucide-react';
+import { History, Pencil, Send, X } from 'lucide-react';
 import { toast } from 'sonner';
 import { api } from '@/api/client';
 import { useSessionStream } from '@/hooks/useSessionStream';
 import { MessageList } from '@/components/MessageList';
 import { ChatInput } from '@/components/ChatInput';
 import { StaleStreamBanner } from '@/components/StaleStreamBanner';
+import { SessionTimeline } from '@/components/SessionTimeline';
+import { TraceViewer } from '@/components/TraceViewer';
 import { sendToChat } from '@/lib/events';
 
 interface Props {
@@ -25,6 +27,7 @@ interface Props {
 export function ChatPane({ sessionId, chatId, projectId, agentId, onAgentChange, sessionChats, webSearchEnabled }: Props) {
   const stream = useSessionStream(sessionId);
   const lastErrorRef = useRef<string | null>(null);
+  const [showTimeline, setShowTimeline] = useState(false);
   const [queue, setQueue] = useState<{ id: string; text: string }[]>([]);
   const queueIdRef = useRef(0);
   const processingRef = useRef(false);
@@ -203,11 +206,41 @@ export function ChatPane({ sessionId, chatId, projectId, agentId, onAgentChange,
     }
   }
 
+  const handleScrollToMessage = useCallback((messageId: string) => {
+    const el = document.getElementById(`msg-${messageId}`);
+    if (el) {
+      el.scrollIntoView({ behavior: 'smooth', block: 'center' });
+    }
+  }, []);
+
   return (
-    <div className="flex flex-col h-full min-h-0">
+    <div className="flex flex-col h-full min-h-0 relative">
+      {chatMessages.length > 0 && (
+        <div className="absolute top-2 right-2 z-10">
+          <button
+            type="button"
+            onClick={() => setShowTimeline((v) => !v)}
+            className={`
+              inline-flex items-center gap-1 px-2 py-1 rounded-md text-xs font-medium
+              transition-colors border
+              ${showTimeline
+                ? 'bg-primary text-primary-foreground border-primary'
+                : 'bg-background text-muted-foreground border-border hover:bg-muted hover:text-foreground'
+              }
+            `}
+            aria-label={showTimeline ? 'Close timeline' : 'Open timeline'}
+          >
+            <History size={12} />
+            Timeline
+          </button>
+        </div>
+      )}
+
       {/* v1.11.5: ContextBar moved into ChatInput (above the agent picker). */}
       <MessageList messages={chatMessages} sessionChats={sessionChats} />
 
+      <TraceViewer chatId={chatId} />
+
       {/* Queued messages */}
       {queue.length > 0 && (
         <div className="border-t">
@@ -275,6 +308,16 @@ export function ChatPane({ sessionId, chatId, projectId, agentId, onAgentChange,
         messages={chatMessages}
         modelContextLimit={modelContextLimit}
       />
+
+      {/* Timeline overlay panel */}
+      {showTimeline && (
+        <SessionTimeline
+          messages={chatMessages}
+          chatId={chatId}
+          onClose={() => setShowTimeline(false)}
+          onScrollToMessage={handleScrollToMessage}
+        />
+      )}
     </div>
   );
 }

apps/web/src/hooks/useSessionStream.ts

@@ -16,6 +16,134 @@ interface State {
   error: string | null;
 }
 
+type Channel = 'text' | 'tool_call' | 'tool_result' | 'status' | 'error';
+
+// Per-channel out-of-order frame buffer with contiguous-seq flush logic.
+// Stores incoming channel_delta frames and releases them only when seq
+// becomes contiguous with the expected next value.
+class ChannelBuffer {
+  private expectedSeq = 0;
+  private buffer = new Map<number, ChannelDeltaWsFrame>();
+
+  push(frame: ChannelDeltaWsFrame): ChannelDeltaWsFrame[] {
+    if (frame.seq < this.expectedSeq) {
+      return [];
+    }
+    if (frame.seq === this.expectedSeq) {
+      this.expectedSeq++;
+      const flushed = [frame];
+      while (this.buffer.has(this.expectedSeq)) {
+        const next = this.buffer.get(this.expectedSeq)!;
+        this.buffer.delete(this.expectedSeq);
+        this.expectedSeq++;
+        flushed.push(next);
+      }
+      return flushed;
+    }
+    this.buffer.set(frame.seq, frame);
+    return [];
+  }
+
+  get expectedNextSeq(): number {
+    return this.expectedSeq;
+  }
+
+  get bufferedCount(): number {
+    return this.buffer.size;
+  }
+
+  reset(seq = 0) {
+    this.expectedSeq = seq;
+    this.buffer.clear();
+  }
+}
+
+type ChannelDeltaWsFrame = WsFrame & { type: 'channel_delta' };
+
+// Converts a flushed channel_delta into the equivalent legacy frame so the
+// existing applyFrame reducer handles the per-message mutation. Status
+// deltas are handled separately (they may need to create the message first
+// and apply throughput metadata independently of terminal status).
+function channelDeltaToLegacyFrame(delta: ChannelDeltaWsFrame): WsFrame | null {
+  switch (delta.channel) {
+    case 'text':
+      return { type: 'delta', message_id: delta.message_id!, content: delta.content! };
+    case 'tool_call':
+      return { type: 'tool_call', message_id: delta.message_id!, tool_call: delta.tool_call! };
+    case 'tool_result':
+      return {
+        type: 'tool_result',
+        tool_message_id: delta.tool_message_id!,
+        chat_id: delta.chat_id,
+        tool_call_id: delta.tool_call_id!,
+        output: delta.output,
+        truncated: delta.truncated!,
+        ...(delta.error ? { error: delta.error } : {}),
+        ...(delta.diff ? { diff: delta.diff } : {}),
+      };
+    case 'error':
+      return {
+        type: 'error',
+        message_id: delta.message_id,
+        chat_id: delta.chat_id,
+        error: delta.error!,
+        ...(delta.reason ? { reason: delta.reason as never } : {}),
+      };
+    case 'status':
+      return null;
+  }
+}
+
+// Apply a flushed status channel_delta to state. Status deltas carry both
+// intermediate throughput metadata (tokens_used, ctx_used, model, etc.)
+// and optional terminal transitions (complete / cancelled / failed).
+function applyStatusDelta(state: State, delta: ChannelDeltaWsFrame): State {
+  const { message_id, chat_id, status, channel: _c, seq: _s, type: _t, ...meta } = delta;
+  if (!message_id) return state;
+  let next = state;
+
+  const exists = next.messages.some((m) => m.id === message_id);
+  if (!exists && status === 'running') {
+    next = applyFrame(next, {
+      type: 'message_started',
+      message_id,
+      chat_id,
+      role: 'assistant',
+    });
+  }
+
+  const metaFields: Record<string, unknown> = {};
+  if (meta.tokens_used !== undefined) metaFields.tokens_used = meta.tokens_used;
+  if (meta.ctx_used !== undefined) metaFields.ctx_used = meta.ctx_used;
+  if (meta.ctx_max !== undefined) metaFields.ctx_max = meta.ctx_max;
+  if (meta.cache_tokens !== undefined) metaFields.cache_tokens = meta.cache_tokens;
+  if (meta.reasoning_tokens !== undefined) metaFields.reasoning_tokens = meta.reasoning_tokens;
+  if (meta.started_at !== undefined) metaFields.started_at = meta.started_at;
+  if (meta.finished_at !== undefined) metaFields.finished_at = meta.finished_at;
+  if (meta.model !== undefined) metaFields.model = meta.model;
+  if (meta.metadata !== undefined) metaFields.metadata = meta.metadata;
+
+  if (Object.keys(metaFields).length > 0) {
+    next = {
+      ...next,
+      messages: next.messages.map((m) =>
+        m.id === message_id ? { ...m, ...metaFields } : m,
+      ),
+    };
+  }
+
+  if (status === 'complete' || status === 'cancelled' || status === 'failed') {
+    next = applyFrame(next, {
+      type: 'message_complete',
+      message_id,
+      chat_id,
+      status,
+    });
+  }
+
+  return next;
+}
+
 function applyFrame(state: State, frame: WsFrame): State {
   switch (frame.type) {
     case 'snapshot': {
@@ -33,18 +161,19 @@ function applyFrame(state: State, frame: WsFrame): State {
         kind: 'message',
         tool_calls: null,
         tool_results: null,
-        // v1.8.2: cap-hit sentinels arrive role='system' and are static, so
-        // skipping the streaming dot for them keeps the UI accurate.
         status: frame.role === 'system' ? 'complete' : 'streaming',
         last_seq: 0,
         tokens_used: null,
         ctx_used: null,
         ctx_max: null,
+        cache_tokens: null,
+        reasoning_tokens: null,
         model: null,
         started_at: null,
         finished_at: null,
         created_at: new Date().toISOString(),
         metadata: null,
+        ...(frame.compare_group_id ? { compare_group_id: frame.compare_group_id } : {}),
       };
       return { ...state, messages: [...state.messages, newMsg] };
     }
@@ -63,27 +192,24 @@ function applyFrame(state: State, frame: WsFrame): State {
       const next = state.messages.map((m) =>
         m.id === frame.message_id
           ? { ...m, tool_calls: [...(m.tool_calls ?? []), frame.tool_call] }
-          : m
+          : m,
       );
       return { ...state, messages: next };
     }
     case 'tool_result': {
-      const exists = state.messages.some((m) => m.id === frame.tool_message_id);
+      const toolResultsBase = {
-      if (exists) {
-        const next = state.messages.map((m) =>
-          m.id === frame.tool_message_id
-            ? {
-                ...m,
-                role: 'tool' as const,
-                tool_results: {
         tool_call_id: frame.tool_call_id,
         output: frame.output,
         truncated: frame.truncated,
         ...(frame.error ? { error: frame.error } : {}),
-                },
+        ...(frame.diff ? { diff: frame.diff } : {}),
-                status: 'complete' as const,
+      };
-              }
+      const exists = state.messages.some((m) => m.id === frame.tool_message_id);
-            : m
+      if (exists) {
+        const next = state.messages.map((m) =>
+          m.id === frame.tool_message_id
+            ? { ...m, role: 'tool' as const, tool_results: toolResultsBase, status: 'complete' as const }
+            : m,
         );
         return { ...state, messages: next };
       }
@@ -95,17 +221,14 @@ function applyFrame(state: State, frame: WsFrame): State {
         content: '',
         kind: 'message',
         tool_calls: null,
-        tool_results: {
+        tool_results: toolResultsBase,
-          tool_call_id: frame.tool_call_id,
-          output: frame.output,
-          truncated: frame.truncated,
-          ...(frame.error ? { error: frame.error } : {}),
-        },
         status: 'complete',
         last_seq: 0,
         tokens_used: null,
         ctx_used: null,
         ctx_max: null,
+        cache_tokens: null,
+        reasoning_tokens: null,
         model: null,
         started_at: null,
         finished_at: null,
@@ -128,19 +251,14 @@ function applyFrame(state: State, frame: WsFrame): State {
               ...(frame.started_at !== undefined ? { started_at: frame.started_at } : {}),
               ...(frame.finished_at !== undefined ? { finished_at: frame.finished_at } : {}),
               ...(frame.model !== undefined ? { model: frame.model } : {}),
-              // v1.8.2: cap-hit sentinels (and future stamped metadata) ride
-              // in on this terminal frame so the reducer can attach it
-              // without waiting for a refetch.
               ...(frame.metadata !== undefined ? { metadata: frame.metadata } : {}),
+              ...(frame.compare_group_id !== undefined ? { compare_group_id: frame.compare_group_id } : {}),
             }
-          : m
+          : m,
       );
       return { ...state, messages: next };
     }
     case 'usage': {
-      // v1.12.2: live throughput. Side-effects into the module-level
-      // singleton consumed by ChatThroughput; no message-state mutation.
-      // chat_id is the optional ws-frame field; usage frames always include it.
       if (frame.chat_id) {
         recordUsage(frame.chat_id, {
           completion_tokens: frame.completion_tokens,
@@ -168,10 +286,6 @@ function applyFrame(state: State, frame: WsFrame): State {
       return state;
     }
     case 'error': {
-      // v1.8.2: when the frame carries a structured reason, stamp it onto the
-      // failed message's metadata so the bubble can render specifics inline
-      // (the WS error frame is one-shot; refresh-safe rendering needs the
-      // value persisted on the message).
       const errorMeta = frame.reason
         ? { kind: 'error' as const, error_reason: frame.reason, error_text: frame.error }
         : null;
@@ -182,48 +296,55 @@ function applyFrame(state: State, frame: WsFrame): State {
                   ...m,
                   status: 'failed' as const,
                   ...(errorMeta ? { metadata: errorMeta } : {}),
+                  ...(frame.compare_group_id !== undefined ? { compare_group_id: frame.compare_group_id } : {}),
                 }
-              : m
+              : m,
           )
         : state.messages;
       return { ...state, messages: next, error: frame.error };
     }
     case 'compacted': {
-      // v1.11: side effects (refetch + toast) live in ws.onmessage; the
+      return state;
-      // reducer just no-ops so TS exhaustiveness is satisfied without
+    }
-      // duplicating async work inside a synchronous reducer.
+    case 'agent_snapshot': {
       return state;
     }
     case 'agent_status_updated': {
-      // agent-status-normalize (#10): coder-only frame consumed by CoderPane's
-      // own WS handler, not BooChat's native message reducer. No-op here to keep
-      // TS exhaustiveness satisfied (native sessions never emit it).
       return state;
     }
     case 'flow_run_started':
     case 'flow_run_step_updated': {
-      // Orchestrator frames consumed by OrchestratorPane's own subscription.
-      // No-op here to keep TS exhaustiveness satisfied.
       return state;
     }
     case 'battle_started':
     case 'contestant_updated':
     case 'battle_updated': {
-      // Arena frames consumed by ArenaPane's own subscription.
+      return state;
-      // No-op here to keep TS exhaustiveness satisfied.
+    }
+    case 'channel_delta': {
+      return state;
+    }
+    default: {
       return state;
     }
   }
 }
 
-// Matches useUserEvents — exponential backoff with the same ceiling so the
-// two channels reconnect on the same cadence after a network handoff.
 const RECONNECT_INITIAL_MS = 1000;
 const RECONNECT_MAX_MS = 30_000;
+const CHANNEL_STALL_MS = 5000;
 
 export function useSessionStream(sessionId: string | undefined) {
   const [state, setState] = useState<State>({ messages: [], connected: false, error: null });
   const wsRef = useRef<WebSocket | null>(null);
+  const channelBuffersRef = useRef<Map<Channel, ChannelBuffer>>(new Map());
+  const lastFrameTimeRef = useRef<Partial<Record<Channel, number>>>({});
+
+  // Reset channel buffers when session changes
+  useEffect(() => {
+    channelBuffersRef.current = new Map();
+    lastFrameTimeRef.current = {};
+  }, [sessionId]);
 
   useEffect(() => {
     if (!sessionId) return;
@@ -234,6 +355,73 @@ export function useSessionStream(sessionId: string | undefined) {
     let reconnectTimer: ReturnType<typeof setTimeout> | null = null;
     let reconnectDelay = RECONNECT_INITIAL_MS;
 
+    const getLastSeqPerChannel = () => {
+      const seqs: Partial<Record<Channel, number>> = {};
+      for (const [ch, buf] of channelBuffersRef.current) {
+        seqs[ch] = buf.expectedNextSeq;
+      }
+      return seqs;
+    };
+
+    const flushDeltaToState = (delta: ChannelDeltaWsFrame) => {
+      console.error('FDS', delta.channel, 'flushed');
+      if (delta.channel === 'status') {
+        setState((s) => applyStatusDelta(s, delta));
+      } else {
+        const legacy = channelDeltaToLegacyFrame(delta);
+        if (legacy) {
+          setState((s) => applyFrame(s, legacy));
+        }
+      }
+    };
+
+    const handleChannelDelta = (frame: ChannelDeltaWsFrame) => {
+      console.error('HCD', frame.channel, frame.seq, 'bufs', channelBuffersRef.current.size);
+      const buffers = channelBuffersRef.current;
+      let buffer = buffers.get(frame.channel);
+      if (!buffer) {
+        buffer = new ChannelBuffer();
+        buffers.set(frame.channel, buffer);
+      }
+
+      const flushed = buffer.push(frame);
+      if (flushed.length === 0) return;
+
+      for (const delta of flushed) {
+        flushDeltaToState(delta);
+      }
+
+      let emittedRefresh = false;
+      for (const delta of flushed) {
+        if (delta.channel === 'status' && (delta.status === 'complete' || delta.status === 'cancelled' || delta.status === 'failed')) {
+          emittedRefresh = true;
+        }
+      }
+      if (emittedRefresh) {
+        sessionEvents.emit({ type: 'git_diff_refresh' });
+      }
+
+      lastFrameTimeRef.current[frame.channel] = Date.now();
+    };
+
+    // Periodic channel stall check: if any channel has buffered frames
+    // but no progress for 5s, force a snapshot refetch.
+    let stallTimer: ReturnType<typeof setInterval> | null = null;
+
+    const startStallTimer = () => {
+      stallTimer = setInterval(() => {
+        const now = Date.now();
+        for (const [channel, buffer] of channelBuffersRef.current) {
+          if (buffer.bufferedCount === 0) continue;
+          const lastTime = lastFrameTimeRef.current[channel as Channel] ?? 0;
+          if (now - lastTime >= CHANNEL_STALL_MS) {
+            buffer.reset();
+            sessionEvents.emit({ type: 'refetch_messages' });
+          }
+        }
+      }, 1000);
+    };
+
     const connect = () => {
       if (unmounted) return;
       const proto = window.location.protocol === 'https:' ? 'wss' : 'ws';
@@ -244,13 +432,16 @@ export function useSessionStream(sessionId: string | undefined) {
       ws.onopen = () => {
         reconnectDelay = RECONNECT_INITIAL_MS;
         setState((s) => ({ ...s, connected: true, error: null }));
+
+        // Mid-stream reconnection protocol: send last known seq per channel
+        // so the server can replay deltas or fall back to a full snapshot.
+        const lastSeq = getLastSeqPerChannel();
+        ws.send(JSON.stringify({ type: 'reconnect', lastSeqPerChannel: lastSeq }));
+
+        startStallTimer();
       };
+
       ws.onmessage = (ev) => {
-        // v1.13.11-a: Zod-validate every inbound frame. Fail-closed — invalid
-        // frames are logged and dropped. WsFrameSchema is the runtime guard;
-        // the hand-maintained WsFrame type stays as the narrowed dev-time
-        // shape (Zod uses OpaqueObject for nested types like Message[]). One
-        // cast bridges the two.
         let raw: unknown;
         try {
           raw = JSON.parse(typeof ev.data === 'string' ? ev.data : '');
@@ -268,13 +459,14 @@ export function useSessionStream(sessionId: string | undefined) {
         }
         try {
           const frame = validated.data as unknown as WsFrame;
-          // v1.11: on a compaction completion, re-fetch the message list so
+
-          // the new summary row + the cohort of compacted_at-stamped older
+          if (frame.type === 'channel_delta') {
-          // rows render correctly. We dispatch the fresh list as a synthetic
+            console.error('RAW_PARSE', JSON.stringify(validated.data).slice(0, 200));
-          // 'snapshot' frame so the reducer's existing path handles state
+            console.error('CD', frame.channel, frame.seq, JSON.stringify(frame).slice(0, 80));
-          // replacement (no need for a parallel "refetched" path).
+            handleChannelDelta(frame);
-          // The toast is purely UX feedback; missing it would still leave
+            return;
-          // the chat in a valid state.
+          }
+
           if (frame.type === 'compacted') {
             toast.success('Context compacted to free space');
             void api.messages
@@ -287,8 +479,9 @@ export function useSessionStream(sessionId: string | undefined) {
               });
             return;
           }
+
           setState((s) => applyFrame(s, frame));
-          // Trigger git diff refresh after each completed assistant turn.
+
           if (frame.type === 'message_complete') {
             sessionEvents.emit({ type: 'git_diff_refresh' });
           }
@@ -296,15 +489,18 @@ export function useSessionStream(sessionId: string | undefined) {
           console.warn('bad ws frame', err);
         }
       };
-      // v1.8.1: WS errors no longer surface as user-facing toasts here. The
+
-      // user-channel hook (useUserEvents) owns the debounced "reconnecting…"
-      // UI; this channel just reconnects silently on the same backoff.
       ws.onerror = () => {
         try { ws.close(); } catch {}
       };
+
       ws.onclose = () => {
         if (unmounted) return;
         setState((s) => ({ ...s, connected: false }));
+        if (stallTimer) {
+          clearInterval(stallTimer);
+          stallTimer = null;
+        }
         const delay = reconnectDelay;
         reconnectDelay = Math.min(reconnectDelay * 2, RECONNECT_MAX_MS);
         reconnectTimer = setTimeout(connect, delay);
@@ -316,6 +512,7 @@ export function useSessionStream(sessionId: string | undefined) {
     return () => {
       unmounted = true;
       if (reconnectTimer) clearTimeout(reconnectTimer);
+      if (stallTimer) clearInterval(stallTimer);
       const ws = wsRef.current;
       wsRef.current = null;
       if (ws) try { ws.close(); } catch {}

codecontext/Dockerfile

@@ -1,44 +0,0 @@
-# v2.8 — boocontext sidecar container.
-# Multi-stage build: Go shim from golang:1.24-alpine, boocontext MCP aggregator
-# from node:20-alpine, then an alpine:3.20 runtime holding both.
-#
-# The shim spawns boocontext as a child MCP process over stdio NDJSON,
-# translating HTTP requests to MCP tools/call.
-#
-# To stage the fork source for a Docker build:
-#   tar -czf codecontext/fork.tar.gz -C /opt/forks/boocontext \
-#     --exclude=.git --exclude=node_modules --exclude=dist
-
-# Stage 1: Go shim builder
-FROM golang:1.24-alpine AS shim-builder
-WORKDIR /build/shim
-RUN apk add --no-cache ca-certificates
-COPY go.mod ./
-COPY shim.go ./
-RUN CGO_ENABLED=0 GOOS=linux go build -o /build/shim-bin ./
-
-# Stage 2: boocontext MCP builder (pnpm project)
-FROM node:20-alpine AS boocontext-builder
-WORKDIR /build/boocontext
-RUN apk add --no-cache git python3 make g++ ca-certificates
-RUN npm install -g pnpm@9 --silent
-COPY fork.tar.gz /build/fork.tar.gz
-RUN mkdir -p /build/boocontext && tar -xzf /build/fork.tar.gz -C /build/boocontext
-WORKDIR /build/boocontext
-RUN pnpm install --frozen-lockfile && pnpm run build
-
-# Stage 3: Runtime
-FROM alpine:3.20
-# uv intentionally not installed — container network blocks astral.sh.
-# tree-sitter-analyzer child server (uvx) won't start in-container, but
-# boocontext logs a graceful warning; TSA-backed tools fall through.
-RUN apk add --no-cache ca-certificates nodejs
-COPY --from=shim-builder /build/shim-bin /usr/local/bin/shim
-COPY --from=boocontext-builder /build/boocontext/dist /usr/local/lib/boocontext/dist
-COPY --from=boocontext-builder /build/boocontext/node_modules /usr/local/lib/boocontext/node_modules
-COPY --from=boocontext-builder /build/boocontext/package.json /usr/local/lib/boocontext/package.json
-
-EXPOSE 8080
-HEALTHCHECK --interval=30s --timeout=5s --start-period=30s \
-  CMD wget -qO- http://localhost:8080/health || exit 1
-ENTRYPOINT ["/usr/local/bin/shim"]

codecontext/README.md

@@ -0,0 +1,31 @@
+# codecontext — Go sidecar (DEPRECATED)
+
+> **Deprecated** (Phase 4, Domain 2, v2.8.14).
+>
+> Superseded by the **boocontext MCP server** (`apps/coder`). Do not add new
+> callers. The 16 codecontext tool wrappers still use this sidecar via HTTP at
+> `http://codecontext:8080/v1/{toolName}` for backward compatibility.
+
+## Migration path
+
+1. Existing tool wrappers in `apps/server/src/services/tools/codecontext/` route
+   through `callCodecontext()` in `codecontext_client.ts`, which calls this
+   Go sidecar over HTTP.
+2. New callers should use the boocontext MCP server instead (reachable via the
+   `boocontext` tool wrappers).
+3. After all callers have migrated, remove this directory, the `codecontext`
+   service block from `docker-compose.yml`, and the
+   `codecontext_client.ts`/`factory.ts` files.
+
+## What it does
+
+A Go HTTP shim wrapping the boocontext MCP server's stdio interface. Provides
+code-graph analysis (symbols, callers, callees, file overview, etc.) over a
+REST API at `/v1/{toolName}`.
+
+## Files
+
+- `shim.go` — HTTP server that wraps the boocontext MCP stdio process
+- `Dockerfile` — container build
+- `fork.tar.gz` — vendored boocontext source (gitignored)
+- `.codecontextignore.template` — default ignore patterns deployed per project

docker-compose.yml

@@ -7,7 +7,6 @@ services:
       - "100.114.205.53:9500:3000"
     env_file: .env
     environment:
-      CODECONTEXT_URL: http://codecontext:8080
       CONTAINER_GUIDANCE_FILE: /app/BOOCHAT.md
       DATABASE_URL: postgres://boocode:${POSTGRES_PASSWORD}@boocode_db:5432/boochat
       BOOCODER_URL: http://100.114.205.53:9502
@@ -91,41 +90,6 @@ services:
     networks:
       - boocode_net
 
-  # v1.12 Track B: codecontext sidecar. Stdio MCP server wrapped by a small
-  # HTTP shim (see ./codecontext/). No host port — reached from boocode at
-  # http://codecontext:8080 over the boocode_net bridge.
-  #
-  # Mounts /opt:/opt:ro (not just /opt/projects:ro): BooCode projects live
-  # at /opt/<slug> on the host, not exclusively under /opt/projects. The
-  # mount must cover anywhere a project.path could resolve to. Read-only
-  # because codecontext only analyzes — never writes. The model can't
-  # arbitrarily set target_dir to a sensitive subtree because the B.2
-  # wrappers validate target_dir against project.path before calling the
-  # shim, and the shim isn't reachable from outside boocode_net.
-  codecontext:
-    build:
-      context: ./codecontext
-    container_name: boocode_codecontext
-    ports:
-      - "127.0.0.1:8080:8080"
-    restart: unless-stopped
-    environment:
-      CODECONTEXT_CHILD: node /usr/local/lib/boocontext/dist/index.js --mcp
-      TYPE_INJECT_MCP_PATH: /opt/type-inject/packages/mcp/dist/index.js
-      TREE_SITTER_MCP_CMD: uvx
-      TREE_SITTER_MCP_ARGS: --from tree-sitter-analyzer[mcp] tree-sitter-analyzer-mcp
-    networks:
-      - boocode_net
-    volumes:
-      - /opt:/opt:ro
-      - /opt/forks:/opt/forks:ro
-    healthcheck:
-      test: ["CMD-SHELL", "wget -qO- http://localhost:8080/health || exit 1"]
-      interval: 30s
-      timeout: 5s
-      retries: 3
-      start_period: 30s
-
 volumes:
   boocode_pgdata:
 

openspec/changes/paseo-orchestrator/proposal.md

@@ -0,0 +1,107 @@
+# Paseo-like Orchestrator — Trace Observability, Dynamic Workflows & Agent Runtime
+
+**Status:** Proposed
+**Epic:** paseo-orchestrator
+**Depends on:** v2.7.17-orchestrator
+
+## Why
+
+BooCode's Orchestrator (v2.7.17) runs deterministic Han analysis flows — but it's a fixed pipeline, not a general-purpose agent runtime. Every tool call is opaque: no timing, no cost breakdown, no replay. Sessions evaporate on browser refresh. Workflows are hardcoded. Subagents block until completion. And there's zero visibility into cache efficiency on DeepSeek — despite prompt caching being a major cost lever.
+
+The current architecture treats the LLM as a black box and the agent as a one-shot transaction. To move from "read-only chat" to a **Paseo-style thin-client orchestration layer**, BooCode needs five capabilities that compound on each other:
+
+1. **Observability** — Every tool call timed, logged, and live-streamed. Without it, debugging agent behavior is guesswork.
+2. **Persistence** — Agent state survives browser refresh. Active sessions resume where they left off.
+3. **Dynamic Workflows** — User-authored JS scripts using `agent()`, `parallel()`, `pipeline()` instead of hardcoded flows. Hash-based caching skips completed steps on re-run.
+4. **Background Subagents** — `spawn_subagent` returns immediately, results collected later. Unlocks parallel research, long-running analyses, and notification-based workflows.
+5. **Multi-modal + Cache Shape** — Image attachments forwarded to DeepSeek's vision API, plus per-turn cache hit rate visualization to close the cost feedback loop.
+
+Each phase is independently valuable; together they transform BooCode from a chat UI into a durable agent execution platform.
+
+## What Changes
+
+### Phase 1: Trace System + Observability (3-4 days)
+
+1. **Create `tool_traces` DB table** — id, session_id, chat_id, turn_number, tool_name, input, output, started_at, finished_at, latency_ms, tokens_used, cache_tokens, reasoning_tokens, error, outcome. Applied idempotently via `applySchema()`.
+
+2. **Add `tool_trace` WS frame** — new WsFrame variant in `@boocode/contracts` published by the server when a tool call starts and completes. Frontend receives live timing deltas via `useSessionStream`.
+
+3. **Instrument `tool-phase.ts`** — wrap `executeToolCall` with `clock_timestamp()` start/end, extract token counts from LLM response metadata, publish `tool_trace` frames on start (with input) and finish (with output + metrics).
+
+4. **Add GET `/api/chats/:id/traces`** — paginated endpoint returning trace rows ordered by turn_number + started_at. Supports cursor-based pagination for large sessions.
+
+5. **Build trace viewer pane** — collapsible tree per turn, timing bars showing latency relative to turn duration, expand/collapse per tool call showing input/output. Integrates into the existing multi-pane workspace alongside chat, coder, and orchestrator panes.
+
+### Phase 2: Session Persistence + Resume (2-3 days)
+
+6. **Serialize agent state to DB** — on each turn boundary (before and after tool call loop), snapshot the active `AgentSession` state (provider config, turn history, pending tool calls) to a JSONB column in `agent_sessions`. Uses `clock_timestamp()` for ordering.
+
+7. **Restore on WS reconnect** — when `snapshot` frame arrives on reconnection, check for a persisted `AgentSession` in `in_progress` or `awaiting_input` state. Rehydrate the coder pane to match the persisted turn, tool call, and pending state.
+
+8. **Agent session timeline view** — a timeline component in the coder pane showing the history of all turns in the current agent session. Each turn shows start time, tool count, token usage, cache hit rate. Clicking a turn scrolls to that point in the conversation.
+
+### Phase 3: Dynamic Workflow Engine (5-7 days)
+
+9. **Create `isolated-vm` sandbox** — restricted JS execution environment for workflow scripts. No `require`, `fs`, `net`, `child_process`. Only the workflow API surface exposed. Token budget enforcement kills runaway scripts.
+
+10. **Implement workflow API primitives** — `agent(id, { prompt, model, tools, budget })` defines a sub-agent; `parallel([agent1, agent2])` runs N agents concurrently with a shared token budget; `pipeline([step1, step2])` chains agents sequentially; `phase(name, { agents, budget })` groups agents under a named phase; `budget(limit)` sets token or step limits; `log(msg)` emits structured workflow log. Compatible with Claude Code workflow script format.
+
+11. **Workflow file discovery** — scan `.boocode/workflows/*.js` (project-local), `~/.boocode/workflows/*.js` (global), and a built-in catalog directory. Each file exports a `workflow` object with `{name, description, run}`. Discovery runs on server start and on file change (optional watch mode).
+
+12. **Workflow manager + built-in catalog** — `WorkflowManager` class with `list()`, `get(name)`, `run(workflow, args)`, `cancel(runId)`, `status(runId)`. Concurrency limits (configurable max concurrent runs), token budgets per run. Built-in catalog includes: `deep-research` (parallel source search → per-source analysis → synthesis), `multi-review` (code health + security + standards reviews in parallel), `plan-verify` (generate plan → verify plan → generate tasks), `bounty-hunt` (parallel vulnerability scanning with different focuses).
+
+13. **Workflow resumability** — SHA-256 hash of each agent spec (prompt + options). Before executing an agent, check if a completed result exists with the same hash. Skip cached agents, only execute new/changed ones. In-memory LRU cache for current session, optional DB persistence for cross-session reuse.
+
+14. **Workflow UI integration** — extend the existing Orchestrator panel (used for Han flows) to support dynamic workflows. Workflow selector dropdown, live run pane with step-by-step progress, cancel button, log output stream, per-agent timing. Reuses the same run-pane component pattern.
+
+### Phase 4: Background Subagents (2-3 days)
+
+15. **Background task queue** — uses the existing `tasks` table with a new `background` type. `spawn_subagent` tool creates a task row and returns immediately. A background worker picks up the task and executes it without blocking the calling agent.
+
+16. **`subagent_status` + `subagent_result` tools** — `subagent_status(task_id)` returns `running|completed|failed` with optional progress info. `subagent_result(task_id)` returns the full output when completed. Polling-based (no WS push for background tasks initially).
+
+17. **Background agent pane** — new pane type showing running/completed background agents. Each entry shows name, status, duration, progress. Completed entries show a "View Result" action. Notifications hook into the existing notification system (toast on completion, badge count for active tasks).
+
+### Phase 5: Multi-modal + Cache Shape (2-3 days)
+
+18. **Image/file attachment pipeline** — accept file uploads (drag-drop or file picker), store on tmpfs with a reference in the message row. Forward to DeepSeek's multimodal API as base64-encoded image parts. Size limit enforcement (configurable, default 20MB per attachment).
+
+19. **Image render in message bubble** — render attached images inline in the chat message bubble. Lightbox on click for expanded view. Thumbnail generation for large images to keep chat scrolling performant.
+
+20. **Cache shape telemetry** — extract `prompt_cache_hit_tokens` from DeepSeek provider metadata on each turn. Break down by segment: system prompt, tool schemas, conversation history. Store in `tool_traces` columns and/or a dedicated `cache_stats` table.
+
+21. **Cache hit rate visualization** — per-turn cache hit bar in the trace viewer (showing cached vs non-cached tokens). Cumulative cache hit rate in the session footer. Highlight when a turn achieves high cache reuse (green indicator) or unusually low (yellow/red).
+
+## Non-Goals
+- No changes to the existing Han flow orchestrator (runs alongside dynamic workflows)
+- No removal of existing agent dispatch paths (PTY, ACP, Claude SDK — dynamic workflows are additive)
+- No distributed execution (all orchestration is single-node)
+- No persistent workflow file watching (manual reload or server restart to pick up new workflows)
+- No workflow editing UI (workflows are authored as JS files)
+
+## Capabilities
+
+### New Capabilities
+- **Tool trace viewer** — every tool call with timing, token costs, cache breakdown, expandable input/output
+- **Agent session resume** — browser refresh preserves active agent state
+- **Dynamic workflows** — user-authored JS scripts with `agent()/parallel()/pipeline()` API
+- **Workflow resumability** — hash-based step caching skips completed agents on re-run
+- **Built-in workflow catalog** — deep-research, multi-review, plan-verify, bounty-hunt
+- **Background subagents** — non-blocking spawn with deferred result collection
+- **Multi-modal support** — image attachments forwarded to DeepSeek vision API
+- **Cache shape telemetry** — per-turn and cumulative cache hit rate visualization
+
+### Modified Capabilities
+- **Orchestrator panel** — extended from fixed Han flows to dynamic workflow selection and streaming run pane
+- **tool-phase.ts** — instrumented with start/end timing and trace publishing
+- **WsFrame contract** — new `tool_trace` frame variant
+- **tasks table** — extended with `background` type for async subagent execution
+
+## Metrics
+- Tool call observability: 0% → 100% of calls traced with timing
+- Session continuity: lost on refresh → preserved on reconnect
+- Workflow authoring: hardcoded → user-authored JS scripts
+- Workflow re-run efficiency: 0% cache → hash-based step reuse
+- Background execution: blocking only → blocking + non-blocking
+- Cache visibility: 0% → per-turn + cumulative hit rate
+- Multi-modal: text-only → text + image attachments

openspec/changes/paseo-orchestrator/tasks.md

@@ -0,0 +1,230 @@
+# Tasks — Paseo-like Orchestrator
+
+## Phase 1: Trace System + Observability (5 tasks)
+
+### 1. Create tool_traces DB table + migration
+Add `tool_traces` table to `apps/server/src/schema.sql`:
+- Columns: id (UUID PK), session_id (UUID FK → sessions), chat_id (UUID FK → chats), turn_number (int), tool_name (text), input (jsonb), output (jsonb), started_at (timestamptz), finished_at (timestamptz), latency_ms (int), tokens_used (int), cache_tokens (int), reasoning_tokens (int), error (text), outcome (text)
+- Index on (chat_id, turn_number, started_at) for trace queries
+- Index on (session_id) for session-level aggregation
+- Applied idempotently via `applySchema()` — wrap in `CREATE TABLE IF NOT EXISTS`
+**Verification**: `psql` shows `tool_traces` table with all columns and indexes. Schema re-run is no-op.
+
+### 2. Add tool_trace WS frame + contracts schema
+Add `tool_trace` frame to `WsFrameSchema` in `packages/contracts/src/ws-frames.ts`:
+- Frame types: `tool_trace:start` (tool_name, input, started_at) and `tool_trace:complete` (tool_name, output, latency_ms, tokens_used, cache_tokens, reasoning_tokens, error)
+- Add to `InferenceFrame` loose union in `apps/server/src/services/inference/turn.ts`
+- Add to strict `WsFrame` discriminated union in `apps/web/src/api/types.ts`
+- Rebuild contracts: `pnpm -C packages/contracts build`
+**Verification**: tsc --noEmit passes. WS client receives `tool_trace:start` and `tool_trace:complete` frames.
+
+### 3. Instrument tool-phase.ts with start/end timing
+Update `apps/server/src/services/tools/tool-phase.ts`:
+- Before `executeToolCall`: record `clock_timestamp()` as start, publish `tool_trace:start` frame with tool_name and input
+- After `executeToolCall`: record `clock_timestamp()` as finish, compute latency_ms, extract token counts from response metadata, INSERT into `tool_traces` table, publish `tool_trace:complete` frame
+- Handle errors: on thrown error, publish `tool_trace:complete` with error field set, set outcome='error'; on success, outcome='success'
+- Use `sql.json(input as never)` for JSONB columns — no double-serialization
+**Verification**: Every tool call produces a `tool_traces` row with correct latency_ms and outcome. WS client receives both start and complete frames.
+
+### 4. Add GET /api/chats/:id/traces endpoint
+Create `apps/server/src/routes/traces.ts`:
+- `GET /api/chats/:id/traces` — paginated, ordered by (turn_number, started_at)
+- Query params: `cursor` (opaque cursor for keyset pagination), `limit` (default 50, max 200), `turn_number` (optional filter to single turn)
+- Returns `{traces: Trace[], next_cursor: string | null}`
+- Register in Fastify router with `chatOwnershipPreHandler` guard
+**Verification**: `curl /api/chats/:id/traces` returns paginated trace rows. Turn filter returns only matching traces.
+
+### 5. Build trace viewer frontend component
+Create `apps/web/src/components/TraceViewer.tsx` (and supporting files):
+- Collapsible tree grouped by turn_number
+- Per tool call row: tool_name badge, latency bar (relative bar width, color-coded: green <1s, yellow <5s, red ≥5s), token count, expand/collapse chevron
+- Expanded view: tool input (JSON formatted), tool output (JSON formatted), error message if any
+- Fetch traces from `/api/chats/:id/traces` on pane mount, paginate on scroll
+- Integrate as a new pane option in the multi-pane workspace (existing pane registry)
+**Verification**: Trace viewer loads, groups by turn, shows timing bars, expands/collapses tool calls. Pagination works for sessions with 50+ traces.
+
+## Phase 2: Session Persistence + Resume (3 tasks)
+
+### 6. Serialize agent state to DB on turn boundaries
+Modify `apps/coder` agent dispatch:
+- On each turn boundary (after LLM response, before next tool call loop), serialize `AgentSession` state to `agent_sessions` table
+- Persist: provider config, turn history, pending tool calls, current phase, token budget remaining
+- Use JSONB column for the snapshot state, `clock_timestamp()` for last_update
+- Guard against rapid consecutive saves (debounce 200ms)
+**Verification**: Agent session state is written to `agent_sessions` after each LLM turn. JSONB snapshot contains all fields needed for resume.
+
+### 7. Restore state on WS reconnect
+Update `apps/server/src/services/ws.ts`:
+- On `snapshot` frame from a reconnecting client, check for `AgentSession` in `in_progress` or `awaiting_input` state
+- If found, rehydrate the coder pane: restore provider config, replay pending tool calls, set turn history
+- Publish a `session_restored` frame with the restored state metadata
+- Client-side: `useSessionStream` handles `session_restored` by resetting pane state to match
+**Verification**: Refresh browser mid-agent-session → after reconnect, the coder pane shows the same turn state, pending tool calls, and conversation history.
+
+### 8. Agent session timeline view
+Add timeline component to the coder pane:
+- Horizontal timeline showing all turns in the current agent session
+- Each turn entry: turn number, start time, tool call count, token usage, cache hit rate
+- Active turn highlighted, past turns dimmed
+- Clicking a past turn scrolls the conversation to that turn and collapses later turns
+- Fetch turn metadata from existing session data (no new endpoint needed)
+**Verification**: Timeline shows all turns. Clicking a turn scrolls to it. Active turn is highlighted.
+
+## Phase 3: Dynamic Workflow Engine (6 tasks)
+
+### 9. Create isolated-vm workflow sandbox
+Create `apps/server/src/services/workflow/sandbox.ts`:
+- Use `isolated-vm` npm package to create a V8 isolate for each workflow run
+- No `require`, `fs`, `net`, `child_process` accessible in the sandbox
+- Expose only the workflow API surface (`agent`, `parallel`, `pipeline`, `phase`, `budget`, `log`, `args`)
+- Token budget enforcement: inject a step counter, throw when budget exceeded
+- Timeout: 30s default, configurable per workflow
+- Error boundary: caught exceptions produce structured error results instead of crashing the worker
+- Add `isolated-vm` to `apps/server/package.json` dependencies
+**Verification**: Workflow script that calls `agent()` runs without error. Script trying `require('fs')` throws a sandbox violation. Run exceeding budget is killed with a clear message.
+
+### 10. Implement agent/parallel/pipeline primitives
+Create `apps/server/src/services/workflow/api.ts`:
+- `agent(id, { prompt, model?, tools?, budget? })` — registers a sub-agent. Returns an object with `.run(input)` that dispatches the agent through the existing agent dispatch system and returns result.
+- `parallel([agents], { budget? })` — runs all agents concurrently. Returns when all complete (or any fails). Shared token budget across parallel agents. Uses `Promise.allSettled` for resilience.
+- `pipeline([steps], { budget? })` — runs steps sequentially. Each step receives the previous step's output. Steps can be `agent()` results or inline functions.
+- `phase(name, { agents, budget })` — groups agents under a named phase. Phases can have their own budget. Results are namespaced by phase name.
+- `budget(limit)` — sets token or step limits. Returns a budget object consumed by agent/parallel/pipeline.
+- `log(msg)` — emits a structured log entry tagged with current phase/agent context. Published as WS frame to the Orchestrator pane.
+- `args` — the input arguments passed to `workflow.run(args)`.
+**Verification**: A test workflow using `agent()`, `parallel()`, and `pipeline()` executes correctly. Logs appear in the output stream. Token budgets are enforced.
+
+### 11. Workflow file discovery system
+Create `apps/server/src/services/workflow/discovery.ts`:
+- Scan `.boocode/workflows/*.js` (project root, relative to `PROJECT_ROOT_WHITELIST`)
+- Scan `~/.boocode/workflows/*.js` (global, `os.homedir()`)
+- Scan `data/workflows/` (built-in catalog)
+- Each file must export a `workflow` object: `{name, description, run(args) => {...}}`
+- Validate the workflow object at discovery time: required fields, run must be a function
+- On server start, run full discovery. Cache results in a `Map<name, Workflow>`.
+- Log discovered workflows with name + description at `info` level
+**Verification**: Placing a valid `.boocode/workflows/test.js` file makes the workflow appear in `WorkflowManager.list()`. Invalid workflow files are logged as warnings and skipped.
+
+### 12. Workflow manager + built-in catalog
+Create `apps/server/src/services/workflow/manager.ts`:
+- `WorkflowManager` singleton class:
+  - `list()` — returns all discovered workflows with name, description, and arg schema
+  - `get(name)` — returns a workflow by name
+  - `run(workflow, args)` — creates a sandbox, injects args, executes `workflow.run()`. Returns a runId (UUID).
+  - `cancel(runId)` — terminates the sandbox, marks run as cancelled
+  - `status(runId)` — returns run status: `pending|running|completed|failed|cancelled`, with progress info
+- Concurrency limit: configurable via `WORKFLOW_MAX_CONCURRENT` env var (default 3)
+- Token budget: configurable via `WORKFLOW_DEFAULT_BUDGET` env var (default 100_000 tokens)
+- Run state tracked in-memory with optional DB persistence
+
+Built-in workflows in `data/workflows/`:
+- `deep-research` — parallel source search → per-source analysis → synthesis report
+- `multi-review` — run code health + security + standards reviews in parallel, merge findings
+- `plan-verify` — generate implementation plan → verify plan → generate work items
+- `bounty-hunt` — parallel vulnerability scans with different focus areas (injection, auth, crypto, business logic)
+**Verification**: `list()` returns built-in workflows. `run()` executes a workflow and returns runId. `status()` reflects progress. `cancel()` stops execution cleanly.
+
+### 13. Workflow resumability (hash-based cache)
+Create `apps/server/src/services/workflow/cache.ts`:
+- Compute SHA-256 hash of each agent spec: `crypto.createHash('sha256').update(JSON.stringify({prompt, options})).digest('hex')`
+- Before executing an agent, check in-memory LRU cache for existing result matching the hash
+- Hit: return cached result, emit `log('cached', agentId, hash)` — no actual dispatch
+- Miss: execute agent, store result in cache keyed by hash
+- LRU eviction: `WORKFLOW_CACHE_SIZE` env var (default 100 entries)
+- Optional DB persistence: `workflow_cache` table with `hash`, `result`, `created_at` — cross-session reuse
+- Re-run detection: identical workflow with same args → all agents skipped
+- Partial re-run: changed args → only changed agents re-execute, unchanged ones read from cache
+**Verification**: First run of a workflow executes all agents. Second run with identical args skips all agents (logs show 'cached'). Run with modified args for one agent only re-executes that agent.
+
+### 14. Workflow UI integration with Orchestrator panel
+Extend `apps/web/src/components/Orchestrator/`:
+- Add workflow selector dropdown listing workflows from `WorkflowManager.list()`
+- Add "Run Workflow" button that opens workflow args editor (JSON or form)
+- Extend existing run pane to show workflow steps with per-agent progress
+- Live log stream from workflow `log()` calls, displayed in a scrollable log view
+- Cancel button for running workflows
+- Resumability indicator: "3/5 steps cached — skipping" when hash cache hits
+- Fetch workflow list via new API endpoint or WS message (add `GET /api/orchestrator/workflows`)
+**Verification**: Workflow selector lists built-in workflows. Running a workflow shows step-by-step progress in the run pane. Cancelling a running workflow works. Cached steps show "skipped" indicator.
+
+## Phase 4: Background Subagents (3 tasks)
+
+### 15. Background task queue + spawn_subagent tool
+Modify `apps/coder/` and `apps/server/`:
+- Extend `tasks` table usage with a new task type marker for background subagent tasks
+- Create `spawn_subagent` tool in `apps/server/src/services/tools/`:
+  - Schema: `{prompt, model?, tools?, budget?, metadata?}`
+  - Creates a `tasks` row with state=`pending`, type=`background_subagent`
+  - Returns `{task_id, status: 'pending'}` immediately — does NOT block
+- Background worker loop: polls `tasks` table for `background_subagent` tasks in `pending` state, picks one up, executes it via existing agent dispatch, writes result back to tasks row on completion
+- Max concurrency: `BACKGROUND_MAX_CONCURRENT` env var (default 2)
+- Worker polls interval: 1s (configurable)
+**Verification**: Calling `spawn_subagent` returns immediately with a task_id. The task eventually completes with a result in the tasks table. Multiple background tasks run concurrently up to the concurrency limit.
+
+### 16. subagent_status + subagent_result tools
+Create two tools in `apps/server/src/services/tools/`:
+- `subagent_status(task_id)`:
+  - Schema: `{task_id}`
+  - Returns: `{task_id, status: 'pending'|'running'|'completed'|'failed', progress?: string, started_at?, finished_at?}`
+  - Queries `tasks` table for the status
+- `subagent_result(task_id)`:
+  - Schema: `{task_id}`
+  - Returns: `{task_id, status, result?: json, error?: string}`
+  - Only returns result when status='completed'; returns empty result otherwise with a message
+  - Updates task state to `read` on successful result retrieval (optional)
+**Verification**: Calling `subagent_status` on a running task returns 'running'. Calling `subagent_result` on a completed task returns the full result. Calling `subagent_result` on a pending task returns a clear "not ready yet" message.
+
+### 17. Background agent pane
+Create `apps/web/src/components/BackgroundAgentPane.tsx`:
+- New pane type showing running, completed, and failed background subagents
+- Each entry: agent name/description, status badge, duration (elapsed or total), progress indicator
+- Running entries: progress bar (if available), cancel button
+- Completed entries: "View Result" action that opens a modal or inline view with the full output
+- Failed entries: error message, "Retry" action
+- Badge counter on pane tab showing number of running tasks
+- Poll status every 2s for running entries, stop polling on completion
+- Register in pane registry alongside existing pane types
+**Verification**: Background pane shows spawning tasks as "pending", transitioning to "running", then "completed"/"failed". "View Result" shows the full output. Badge counter reflects active running tasks.
+
+## Phase 5: Multi-modal + Cache Shape (4 tasks)
+
+### 18. Multi-modal attachment pipeline
+Add file upload support:
+- Accept file uploads via drag-drop or file picker in the message input area
+- Store uploaded files on tmpfs (`/tmp/boocode-uploads/` by default, configurable via `UPLOAD_DIR`)
+- Reference attachments in message row via `message_parts` with `type='image'` and a `url` pointing to the tmpfs path
+- Forward to DeepSeek API: encode image as base64 data URI, send as multimodal content part in the user message
+- Supported formats: png, jpg, jpeg, gif, webp
+- Size limit: 20MB default, configurable via `MAX_ATTACHMENT_SIZE_MB` env var
+- Server-side cleanup: delete tmpfs files after message is fully processed or on a periodic sweep
+**Verification**: Uploading an image creates a file on tmpfs and a referenced `message_parts` row. DeepSeek API call includes the image as a base64 content part. Error on files over size limit.
+
+### 19. Image render in message bubble
+Update message rendering in `apps/web/src/components/MessageBubble.tsx`:
+- Detect `message_parts` with `type='image'` in the message content
+- Render attached images inline in the chat bubble, below the text content
+- Thumbnail: max 300px wide, aspect-ratio preserved, rounded corners
+- Lightbox: clicking the thumbnail opens a full-size overlay with close button
+- Loading state: skeleton placeholder while image loads from tmpfs URL
+- Error state: broken image placeholder with retry option
+- Clean layout: images displayed in a grid (1-2 columns depending on count)
+**Verification**: Chat messages with image attachments render inline thumbnails. Clicking opens lightbox. Large images are thumbnailed. Broken images show error state.
+
+### 20. Cache shape telemetry data pipeline
+Extract and store cache metrics:
+- In the DeepSeek provider response handler, extract `prompt_cache_hit_tokens` and `prompt_cache_miss_tokens` from the API response metadata
+- Break down cache segments: system prompt tokens, tool schema tokens, conversation history tokens (approximate by measuring each segment length)
+- Store cache metrics in `tool_traces.cache_tokens` column (already created in Phase 1)
+- Optionally create a `cache_stats` table for per-segment breakdown: `{turn_id, segment_name, hit_tokens, miss_tokens}`
+- Expose via existing traces API (cache fields already part of the Trace schema)
+**Verification**: After a DeepSeek call, `tool_traces` row has `cache_tokens` populated. Cache segment breakdown is available when querying traces.
+
+### 21. Cache shape visualization in trace viewer
+Update the TraceViewer component with cache metrics:
+- Per-turn cache hit bar: horizontal stacked bar showing cached (green) vs non-cached (gray) tokens
+- Hit rate percentage displayed as a badge next to token count
+- Cumulative cache hit rate in the session footer: "Cache hit rate: 67% (45K/67K tokens)"
+- Color coding: green ≥60%, yellow 30-59%, red <30%
+- Tooltip on hover showing segment breakdown if available
+- Animate transitions when new trace data arrives
+**Verification**: Trace viewer shows cache hit/miss bars per turn. Cumulative rate in footer updates as new traces load. Color coding matches thresholds.

packages/contracts/src/ws-frames.ts

@@ -76,6 +76,8 @@ export const MessageStartedFrame = z.object({
   message_id: Uuid,
   chat_id: Uuid.optional(),
   role: MessageRoleValue,
+  // v2.8-compare: groups messages belonging to the same compare operation.
+  compare_group_id: z.string().uuid().optional(),
 });
 
 export const DeltaFrame = z.object({
@@ -83,6 +85,7 @@ export const DeltaFrame = z.object({
   message_id: Uuid,
   chat_id: Uuid.optional(),
   content: z.string(),
+  compare_group_id: z.string().uuid().optional(),
 });
 
 export const ReasoningDeltaFrame = z.object({
@@ -107,6 +110,10 @@ export const ToolResultFrame = z.object({
   output: z.unknown(),
   truncated: z.boolean(),
   error: z.string().optional(),
+  // v2.8: unified diff for write tools (edit_file, create_file, etc.).
+  // Published alongside successful tool results so the frontend can render
+  // a compact diff snippet inline. Absent for read-only tools or failures.
+  diff: z.string().optional(),
 });
 
 export const MessageCompleteFrame = z.object({
@@ -132,6 +139,7 @@ export const MessageCompleteFrame = z.object({
   // web reducer can render a muted "Stopped" / failed state without a new frame
   // type. Optional → fail-closed publishFrame must keep, not strip, it.
   status: z.enum(['complete', 'cancelled', 'failed']).optional(),
+  compare_group_id: z.string().uuid().optional(),
 });
 
 export const UsageFrame = z.object({
@@ -168,6 +176,7 @@ export const ErrorFrame = z.object({
   chat_id: Uuid.optional(),
   error: z.string(),
   reason: ErrorReasonValue.optional(),
+  compare_group_id: z.string().uuid().optional(),
 });
 
 // ---- per-user channel frames (sidebar refresh) -----------------------------
@@ -355,7 +364,7 @@ export const FlowRunStepUpdatedFrame = z.object({
   type: z.literal('flow_run_step_updated'),
   run_id: Uuid,
   step_id: z.string().min(1),
-  status: z.enum(['pending', 'running', 'completed', 'failed', 'skipped', 'cancelled']),
+  status: z.enum(['pending', 'running', 'completed', 'failed', 'skipped', 'cancelled', 'timed_out']),
   run_status: z.enum(['running', 'completed', 'failed', 'cancelled']).optional(),
   report: z.string().optional(),
 });
@@ -407,11 +416,144 @@ export const BattleUpdatedFrame = z.object({
   cross_exam_id: Uuid.optional(),
 });
 
+// ---- agent snapshot restore frame ------------------------------------------
+
+export const AgentSnapshotFrame = z.object({
+  type: z.literal('agent_snapshot'),
+  chat_id: z.string().uuid(),
+  agent: z.string().nullable().optional(),
+  model: z.string(),
+  mode: z.string().nullable().optional(),
+  turn_number: z.number().int().nonnegative(),
+});
+
+// ---- tool trace frames -----------------------------------------------------
+
+export const ToolTraceStartFrame = z.object({
+  type: z.literal('tool_trace_start'),
+  trace_id: z.string().uuid(),
+  message_id: z.string().uuid(),
+  chat_id: z.string().uuid(),
+  tool_name: z.string().min(1),
+  tool_input: z.record(z.unknown()),
+  started_at: z.string().datetime(),
+});
+
+export const ToolTraceFinishFrame = z.object({
+  type: z.literal('tool_trace_finish'),
+  trace_id: z.string().uuid(),
+  message_id: z.string().uuid(),
+  chat_id: z.string().uuid(),
+  tool_name: z.string().min(1),
+  tool_output: z.union([z.string(), z.null()]).optional(),
+  latency_ms: z.number().int().nonnegative().optional(),
+  tokens_used: z.number().int().nonnegative().nullable().optional(),
+  cache_tokens: z.number().int().nonnegative().nullable().optional(),
+  reasoning_tokens: z.number().int().nonnegative().nullable().optional(),
+  error: z.string().optional(),
+  outcome: z.string().optional(),
+  finished_at: z.string().datetime(),
+});
+
+// ---- collision warning frame (v2.8) ----------------------------------------
+//
+// Published when the BooCoder detects that multiple worktrees/agents are editing
+// the same file concurrently. Advisory only — writes are not blocked.
+
+const ConflictSeverityValue = z.enum(['same_line', 'adjacent_line', 'different_area']);
+
+export const CollisionWarningFrame = z.object({
+  type: z.literal('collision_warning'),
+  file_path: z.string().min(1),
+  worktrees: z.array(z.string().min(1)),
+  agents: z.array(z.string().min(1)),
+  severity: ConflictSeverityValue,
+});
+
+// ---- channel-delta frames (streaming v2) ----------------------------------
+//
+// Each channel frame carries a monotonic `seq` counter so the client can
+// reorder out-of-order deltas per-channel, detect gaps, and request replay on
+// reconnect. The `channel` discriminator tells the reducer which substate to
+// update.
+
+const TextChannelPayload = z.object({
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  content: z.string(),
+  compare_group_id: z.string().uuid().optional(),
+});
+
+const ToolCallChannelPayload = z.object({
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  tool_call: ToolCallShape,
+});
+
+const ToolResultChannelPayload = z.object({
+  tool_message_id: Uuid,
+  chat_id: Uuid.optional(),
+  tool_call_id: ToolCallId,
+  output: z.unknown(),
+  truncated: z.boolean(),
+  error: z.string().optional(),
+  diff: z.string().optional(),
+});
+
+const StatusChannelPayload = z.object({
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  status: z.enum(['running', 'complete', 'cancelled', 'failed']).optional(),
+  tokens_used: z.number().int().nonnegative().nullable().optional(),
+  ctx_used: z.number().int().nonnegative().nullable().optional(),
+  ctx_max: z.number().int().positive().nullable().optional(),
+  cache_tokens: z.number().int().nonnegative().nullable().optional(),
+  reasoning_tokens: z.number().int().nonnegative().nullable().optional(),
+  started_at: IsoTimestamp.nullable().optional(),
+  finished_at: IsoTimestamp.nullable().optional(),
+  model: z.string().nullable().optional(),
+  metadata: OpaqueObject.nullable().optional(),
+});
+
+const ErrorChannelPayload = z.object({
+  message_id: Uuid.optional(),
+  chat_id: Uuid.optional(),
+  error: z.string(),
+  reason: ErrorReasonValue.optional(),
+});
+
+const ChannelDeltaPayload = z.discriminatedUnion('channel', [
+  z.object({ channel: z.literal('text'), ...TextChannelPayload.shape }),
+  z.object({ channel: z.literal('tool_call'), ...ToolCallChannelPayload.shape }),
+  z.object({ channel: z.literal('tool_result'), ...ToolResultChannelPayload.shape }),
+  z.object({ channel: z.literal('status'), ...StatusChannelPayload.shape }),
+  z.object({ channel: z.literal('error'), ...ErrorChannelPayload.shape }),
+]);
+
+export const ChannelDeltaFrame = z.object({
+  type: z.literal('channel_delta'),
+  seq: z.number().int().nonnegative(),
+  channel: z.union([
+    z.literal('text'), z.literal('tool_call'),
+    z.literal('tool_result'), z.literal('status'), z.literal('error'),
+  ]),
+  message_id: Uuid.optional(),
+  chat_id: Uuid.optional(),
+  content: z.string().optional(),
+  tool_call: ToolCallShape.optional(),
+  tool_message_id: Uuid.optional(),
+  tool_call_id: ToolCallId.optional(),
+  output: z.unknown().optional(),
+  truncated: z.boolean().optional(),
+  diff: z.string().optional(),
+});
+
 // ---- discriminated union ---------------------------------------------------
 
 export const WsFrameSchema = z.discriminatedUnion('type', [
   // per-session
   SnapshotFrame,
+  AgentSnapshotFrame,
   MessageStartedFrame,
   DeltaFrame,
   ReasoningDeltaFrame,
@@ -434,6 +576,13 @@ export const WsFrameSchema = z.discriminatedUnion('type', [
   BattleStartedFrame,
   ContestantUpdatedFrame,
   BattleUpdatedFrame,
+  // tool trace
+  ToolTraceStartFrame,
+  ToolTraceFinishFrame,
+  // collision warning
+  CollisionWarningFrame,
+  // channel-delta (streaming v2)
+  ChannelDeltaFrame,
   // per-user
   ChatStatusFrame,
   SessionUpdatedFrame,
@@ -461,6 +610,7 @@ export type WsFrame = z.infer<typeof WsFrameSchema>;
 // by the drift test in src/__tests__/ws-frames.test.ts.
 export const KNOWN_FRAME_TYPES: readonly WsFrame['type'][] = [
   'snapshot',
+  'agent_snapshot',
   'message_started',
   'delta',
   'reasoning_delta',
@@ -481,6 +631,10 @@ export const KNOWN_FRAME_TYPES: readonly WsFrame['type'][] = [
   'battle_started',
   'contestant_updated',
   'battle_updated',
+  'tool_trace_start',
+  'tool_trace_finish',
+  'collision_warning',
+  'channel_delta',
   'chat_status',
   'session_updated',
   'session_renamed',

pnpm-lock.yaml

@@ -97,6 +97,9 @@ importers:
 
   apps/server:
     dependencies:
+      '@ai-sdk/deepseek':
+        specifier: ^2.0.35
+        version: 2.0.35(zod@3.25.76)
       '@ai-sdk/openai-compatible':
         specifier: ^2.0.47
         version: 2.0.47(zod@3.25.76)
@@ -302,6 +305,12 @@ packages:
     peerDependencies:
       zod: ^3.25.0 || ^4.0.0
 
+  '@ai-sdk/deepseek@2.0.35':
+    resolution: {integrity: sha512-9DhYurbAvcurOEGN6u2myYDybrrzGfcrkG8hwmFjwTrePW6KCMggm0YxP7e8RkLYcQKqCEMgFlyEB4BM6EmiKg==}
+    engines: {node: '>=18'}
+    peerDependencies:
+      zod: ^3.25.76 || ^4.1.8
+
   '@ai-sdk/gateway@3.0.119':
     resolution: {integrity: sha512-VAhfRWC+JexZakkVfmjaJKaTj00x7/UHdE8kMWL3NhuQAlf8oXtg9r4dfvFZrByXxchGRBvYE3biEUyibkg0xg==}
     engines: {node: '>=18'}
@@ -4363,6 +4372,12 @@ snapshots:
     dependencies:
       zod: 3.25.76
 
+  '@ai-sdk/deepseek@2.0.35(zod@3.25.76)':
+    dependencies:
+      '@ai-sdk/provider': 3.0.10
+      '@ai-sdk/provider-utils': 4.0.27(zod@3.25.76)
+      zod: 3.25.76
+
   '@ai-sdk/gateway@3.0.119(zod@3.25.76)':
     dependencies:
       '@ai-sdk/provider': 3.0.10