v1.13.11-b: convert raw broker.publish call sites to typed publishFrame

Second half of the WebSocket-frame-typing batch. Phase A (8b568b3)
landed the schemas + frontend receive validation + publishFrame /
publishUserFrame wrappers. This commit converts the existing publish
call sites so every server-emitted WS frame now goes through Zod
validation at the broker boundary.

Conversion strategy: change once in the inference / skills adapters in
index.ts (so ctx.publish / ctx.publishUser propagate to publishFrame /
publishUserFrame for ALL ~50 inference + auto_name call sites in one
move), then bulk-replace the ~30 direct broker.publish* call sites in
the routes + compaction.

Files touched:
- index.ts: inference + skills route adapters now call publishFrame /
  publishUserFrame internally; raw broker.publishUser('default', ...)
  call in the stale-row sweeper also converted.
- routes/projects.ts (7 sites), routes/chats.ts (9 sites),
  routes/sessions.ts (8 sites): all broker.publishUser(...) → broker.
  publishUserFrame(...).
- services/compaction.ts (3 sites): 2 publishUser, 1 publish.

Real protocol drift surfaced by Zod, fixed in the same commit:

  services/compaction.ts:442 was publishing chat_status with status:
  'working' — the v1.12.1 chat_status widening (CLAUDE.md:55) dropped
  this enum value in favor of streaming|tool_running|waiting_for_input|
  idle|error. The compaction.ts site was missed during v1.12.1; the
  frame had been published with an unknown enum value ever since (the
  frontend useChatStatus quietly ignored it). Corrected to 'streaming'
  — compaction's LLM call has the same dot-state semantic as an
  inference turn. This is exactly the class of bug v1.13.11 exists to
  catch.

Schema relaxation: OpaqueObject (the bag type for nested entities like
Project / Chat / Session / WorkspacePane embedded in WS frames) was
z.object({}).passthrough(), which Zod outputs as {} & {[k:string]:
unknown}. The strict-typed entities don't have index signatures so
TypeScript rejected them at publishFrame call sites. Relaxed to
z.unknown() — runtime validation still accepts the value, dev-time
narrowing happens via the existing hand-maintained types. Trade-off:
frame-level drift detection stays sharp; nested-payload validation
goes to follow-up work as the brief intended.

Schema audit:
  grep -rn "broker\.publish(\|broker\.publishUser(" apps/server/src \
    --include="*.ts" | grep -v "broker.ts\|__tests__\|.bak"
  → 0 results. Every server publish goes through publishFrame /
  publishUserFrame. The remaining ctx.publish / ctx.publishUser sites
  in services/inference/* + services/auto_name.ts route through the
  index.ts adapter, which calls publishFrame internally.

Tests: 219/219 pass (unchanged from v1.13.11-a; the Phase B conversion
is mechanical and doesn't add test cases).

Smoke: clean container boot, no ws-frame-validation-failed entries
under normal traffic. Sidebar list refresh + agent picker open both
pass through useUserEvents without drops.

~70 LoC across 7 files. v1.13.11 closed.

apps/server/src/index.ts

@@ -75,7 +75,7 @@ async function main() {
     return { status: dbOk ? 'ok' : 'degraded', db: dbOk };
   });
 
-  const broker = createBroker();
+  const broker = createBroker(app.log);
 
   registerProjectRoutes(app, sql, config, broker);
   registerSessionRoutes(app, sql, config, broker);
@@ -101,7 +101,9 @@ async function main() {
       config,
       log: app.log,
       publish: (sessionId, frame) => {
-        broker.publish(sessionId, frame as unknown as Record<string, unknown> & { type: string });
+        // v1.13.11-b: route through the typed publishFrame so the broker's
+        // Zod gate validates every inference frame before delivery.
+        broker.publishFrame(sessionId, frame as unknown as import('./types/ws-frames.js').WsFrame);
       },
       // v1.11: broker handle for compaction.process to publish 'compacted'
       // frames on the per-session channel. Inference's regular publish path
@@ -110,7 +112,7 @@ async function main() {
       broker,
     },
     (user, frame) => {
-      broker.publishUser(user, frame as unknown as Record<string, unknown> & { type: string });
+      broker.publishUserFrame(user, frame as unknown as import('./types/ws-frames.js').WsFrame);
     }
   );
   registerMessageRoutes(app, sql, {
@@ -129,33 +131,33 @@ async function main() {
     },
     hasActiveInference: (chatId) => inference.hasActive(chatId),
     publishUserMessage: (sessionId, chatId, userMessageId, content) => {
-      broker.publish(sessionId, {
+      broker.publishFrame(sessionId, {
         type: 'message_started',
         message_id: userMessageId,
         chat_id: chatId,
         role: 'user',
       });
-      broker.publish(sessionId, {
+      broker.publishFrame(sessionId, {
         type: 'delta',
         message_id: userMessageId,
         chat_id: chatId,
         content,
       });
-      broker.publish(sessionId, {
+      broker.publishFrame(sessionId, {
         type: 'message_complete',
         message_id: userMessageId,
         chat_id: chatId,
       });
     },
     publishMessagesDeleted: (sessionId, chatId, messageIds) => {
-      broker.publish(sessionId, {
+      broker.publishFrame(sessionId, {
         type: 'messages_deleted',
         message_ids: messageIds,
         chat_id: chatId,
       });
     },
     publishSessionFrame: (sessionId, frame) => {
-      broker.publish(sessionId, frame);
+      broker.publishFrame(sessionId, frame as import('./types/ws-frames.js').WsFrame);
     },
   });
   registerSkillsRoutes(app, sql, {
@@ -163,26 +165,26 @@ async function main() {
       inference.enqueue(sessionId, chatId, assistantId, user);
     },
     publishUserMessage: (sessionId, chatId, userMessageId, content) => {
-      broker.publish(sessionId, {
+      broker.publishFrame(sessionId, {
         type: 'message_started',
         message_id: userMessageId,
         chat_id: chatId,
         role: 'user',
       });
-      broker.publish(sessionId, {
+      broker.publishFrame(sessionId, {
         type: 'delta',
         message_id: userMessageId,
         chat_id: chatId,
         content,
       });
-      broker.publish(sessionId, {
+      broker.publishFrame(sessionId, {
         type: 'message_complete',
         message_id: userMessageId,
         chat_id: chatId,
       });
     },
     publishSessionFrame: (sessionId, frame) => {
-      broker.publish(sessionId, frame);
+      broker.publishFrame(sessionId, frame as import('./types/ws-frames.js').WsFrame);
     },
   });
   registerWebSocket(app, sql, broker);
@@ -230,7 +232,7 @@ async function main() {
       for (const row of rows) {
         if (seenChats.has(row.chat_id)) continue;
         seenChats.add(row.chat_id);
-        broker.publishUser('default', {
+        broker.publishUserFrame('default', {
           type: 'chat_status',
           chat_id: row.chat_id,
           status: 'idle',

apps/server/src/routes/chats.ts

@@ -102,7 +102,7 @@ export function registerChatRoutes(
         VALUES (${req.params.id}, ${parsed.data.name ?? null}, 'open')
         RETURNING id, session_id, name, status, created_at, updated_at
       `;
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'chat_created',
         chat: chat!,
         session_id: req.params.id,
@@ -132,7 +132,7 @@ export function registerChatRoutes(
         return { error: 'chat not found' };
       }
       const chat = rows[0]!;
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'chat_updated',
         chat_id: chat.id,
         session_id: chat.session_id,
@@ -162,7 +162,7 @@ export function registerChatRoutes(
       `;
       const ids = rows.map((r) => r.id);
       for (const id of ids) {
-        broker.publishUser('default', {
+        broker.publishUserFrame('default', {
           type: 'chat_archived',
           chat_id: id,
           session_id: req.params.id,
@@ -203,7 +203,7 @@ export function registerChatRoutes(
         return { error: 'chat not found or already archived' };
       }
       const row = rows[0]!;
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'chat_archived',
         chat_id: row.id,
         session_id: row.session_id,
@@ -226,7 +226,7 @@ export function registerChatRoutes(
         return { error: 'chat not found or not archived' };
       }
       const chat = rows[0]!;
-      broker.publishUser('default', { type: 'chat_unarchived', chat });
+      broker.publishUserFrame('default', { type: 'chat_unarchived', chat });
       return chat;
     }
   );
@@ -243,7 +243,7 @@ export function registerChatRoutes(
         return { error: 'chat not found' };
       }
       const row = result[0]!;
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'chat_deleted',
         chat_id: row.id,
         session_id: row.session_id,
@@ -338,7 +338,7 @@ export function registerChatRoutes(
         return chat!;
       });
 
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'chat_created',
         chat: newChat,
         session_id: source.session_id,
@@ -400,13 +400,13 @@ export function registerChatRoutes(
         reply.code(409);
         return { error: 'message status changed mid-request' };
       }
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'chat_status',
         chat_id: msg.chat_id,
         status: 'idle',
         at: new Date().toISOString(),
       });
-      broker.publish(msg.session_id, {
+      broker.publishFrame(msg.session_id, {
         type: 'message_complete',
         message_id: msg.id,
         chat_id: msg.chat_id,

apps/server/src/routes/projects.ts

@@ -129,7 +129,7 @@ export function registerProjectRoutes(
         RETURNING id, name, path, added_at, last_session_id, status, gitea_remote,
                   default_system_prompt, default_web_search_enabled
       `;
-      broker.publishUser('default', { type: 'project_created', project: row as unknown as Project });
+      broker.publishUserFrame('default', { type: 'project_created', project: row as unknown as Project });
       reply.code(201);
       return {
         project: row,
@@ -186,11 +186,11 @@ export function registerProjectRoutes(
     `;
 
     if (existing.length === 0) {
-      broker.publishUser('default', { type: 'project_created', project: row as unknown as Project });
+      broker.publishUserFrame('default', { type: 'project_created', project: row as unknown as Project });
       reply.code(201);
     } else {
       // existing.status was 'archived' — row has been restored.
-      broker.publishUser('default', { type: 'project_unarchived', project: row as unknown as Project });
+      broker.publishUserFrame('default', { type: 'project_unarchived', project: row as unknown as Project });
       reply.code(200);
     }
     return row;
@@ -243,7 +243,7 @@ export function registerProjectRoutes(
     // v1.9: the project_updated frame still only carries id + name. Clients
     // that need the new fields refetch via api.projects.list() — keeps the
     // frame payload lean, per the locked recon decision (d).
-    broker.publishUser('default', {
+    broker.publishUserFrame('default', {
       type: 'project_updated',
       project_id: project.id,
       name: project.name,
@@ -260,7 +260,7 @@ export function registerProjectRoutes(
       reply.code(404);
       return { error: 'not found or already archived' };
     }
-    broker.publishUser('default', { type: 'project_archived', project_id: req.params.id });
+    broker.publishUserFrame('default', { type: 'project_archived', project_id: req.params.id });
     reply.code(204);
     return null;
   });
@@ -277,7 +277,7 @@ export function registerProjectRoutes(
       return { error: 'not found or not archived' };
     }
     const project = rows[0]!;
-    broker.publishUser('default', { type: 'project_unarchived', project });
+    broker.publishUserFrame('default', { type: 'project_unarchived', project });
     return project;
   });
 
@@ -288,7 +288,7 @@ export function registerProjectRoutes(
       reply.code(404);
       return { error: 'not found' };
     }
-    broker.publishUser('default', { type: 'project_deleted', project_id: id });
+    broker.publishUserFrame('default', { type: 'project_deleted', project_id: id });
     reply.code(204);
     return null;
   });

apps/server/src/routes/sessions.ts

@@ -112,7 +112,7 @@ export function registerSessionRoutes(
         `;
         return session!;
       });
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'session_created',
         session: row,
         project_id: row.project_id,
@@ -178,7 +178,7 @@ export function registerSessionRoutes(
       }
       const session = rows[0]!;
       if (name !== undefined && session.name !== priorName) {
-        broker.publishUser('default', {
+        broker.publishUserFrame('default', {
           type: 'session_renamed',
           session_id: session.id,
           name: session.name,
@@ -188,7 +188,7 @@ export function registerSessionRoutes(
       // (notably the SettingsPane open in another tab) can refetch and pick
       // up the new fields. Frame stays lean (decision d) — payload is just
       // ids + name + updated_at, the client refetches via api.sessions.get.
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'session_updated',
         session_id: session.id,
         project_id: session.project_id,
@@ -220,7 +220,7 @@ export function registerSessionRoutes(
         return { error: 'session not found' };
       }
       const session = rows[0]!;
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'session_workspace_updated',
         session_id: session.id,
         workspace_panes: session.workspace_panes,
@@ -248,7 +248,7 @@ export function registerSessionRoutes(
       `;
       const ids = rows.map((r) => r.id);
       for (const id of ids) {
-        broker.publishUser('default', {
+        broker.publishUserFrame('default', {
           type: 'session_archived',
           session_id: id,
           project_id: req.params.id,
@@ -289,7 +289,7 @@ export function registerSessionRoutes(
         reply.code(404);
         return { error: 'session not found or already archived' };
       }
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'session_archived',
         session_id: rows[0]!.id,
         project_id: rows[0]!.project_id,
@@ -312,7 +312,7 @@ export function registerSessionRoutes(
         return { error: 'session not found or not archived' };
       }
       const session = rows[0]!;
-      broker.publishUser('default', {
+      broker.publishUserFrame('default', {
         type: 'session_created',
         session: session,
         project_id: session.project_id,
@@ -334,7 +334,7 @@ export function registerSessionRoutes(
         return { error: 'not found' };
       }
       const project_id = deleted[0]!.project_id;
-      broker.publishUser('default', { type: 'session_deleted', session_id: id, project_id });
+      broker.publishUserFrame('default', { type: 'session_deleted', session_id: id, project_id });
       reply.code(204);
       return null;
     }

apps/server/src/services/__tests__/ws-frames.test.ts

@@ -0,0 +1,218 @@
+import { describe, it, expect, vi, beforeEach, afterEach } from 'vitest';
+import { readFileSync } from 'node:fs';
+import { resolve } from 'node:path';
+import { fileURLToPath } from 'node:url';
+import {
+  WsFrameSchema,
+  KNOWN_FRAME_TYPES,
+  type WsFrame,
+} from '../../types/ws-frames.js';
+import { createBroker } from '../broker.js';
+
+const VALID_UUID_A = '00000000-0000-0000-0000-000000000001';
+const VALID_UUID_B = '00000000-0000-0000-0000-000000000002';
+const VALID_UUID_C = '00000000-0000-0000-0000-000000000003';
+const VALID_TIMESTAMP = '2026-05-22T14:30:00.000Z';
+
+describe('WsFrameSchema (v1.13.11-a)', () => {
+  it('accepts a well-formed chat_status frame', () => {
+    const result = WsFrameSchema.safeParse({
+      type: 'chat_status',
+      chat_id: VALID_UUID_A,
+      status: 'streaming',
+      at: VALID_TIMESTAMP,
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('rejects an unknown frame type', () => {
+    const result = WsFrameSchema.safeParse({
+      type: 'cosmic_ray_strike',
+      chat_id: VALID_UUID_A,
+    });
+    expect(result.success).toBe(false);
+  });
+
+  it('rejects a chat_status frame with invalid status enum', () => {
+    // v1.12.1 dropped the legacy 'working' status. Any frame still emitting it
+    // should fail validation — that's a drift catcher.
+    const result = WsFrameSchema.safeParse({
+      type: 'chat_status',
+      chat_id: VALID_UUID_A,
+      status: 'working',
+      at: VALID_TIMESTAMP,
+    });
+    expect(result.success).toBe(false);
+  });
+
+  it('rejects a UUID field with a non-UUID string', () => {
+    const result = WsFrameSchema.safeParse({
+      type: 'chat_status',
+      chat_id: 'not-a-uuid',
+      status: 'idle',
+      at: VALID_TIMESTAMP,
+    });
+    expect(result.success).toBe(false);
+  });
+
+  it('rejects negative token counts in usage frame', () => {
+    const result = WsFrameSchema.safeParse({
+      type: 'usage',
+      message_id: VALID_UUID_A,
+      chat_id: VALID_UUID_B,
+      completion_tokens: -1,
+      ctx_used: 100,
+      ctx_max: 1000,
+    });
+    expect(result.success).toBe(false);
+  });
+
+  it('accepts a usage frame with nullable token counts (pre-v1.13.7 history)', () => {
+    const result = WsFrameSchema.safeParse({
+      type: 'usage',
+      message_id: VALID_UUID_A,
+      chat_id: VALID_UUID_B,
+      completion_tokens: null,
+      ctx_used: null,
+      ctx_max: null,
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('accepts a tool_result frame with non-UUID tool_call_id (model-emitted)', () => {
+    // Model-emitted tool_call_ids look like "call_abc123", not UUIDs.
+    const result = WsFrameSchema.safeParse({
+      type: 'tool_result',
+      tool_message_id: VALID_UUID_A,
+      chat_id: VALID_UUID_B,
+      tool_call_id: 'call_abc123',
+      output: { whatever: true },
+      truncated: false,
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('accepts a compacted frame', () => {
+    const result = WsFrameSchema.safeParse({
+      type: 'compacted',
+      session_id: VALID_UUID_A,
+      chat_id: VALID_UUID_B,
+      summary_message_id: VALID_UUID_C,
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('accepts a session_workspace_updated frame', () => {
+    const result = WsFrameSchema.safeParse({
+      type: 'session_workspace_updated',
+      session_id: VALID_UUID_A,
+      workspace_panes: [{ id: 'p1', kind: 'chat', chatIds: [], activeChatIdx: 0 }],
+    });
+    expect(result.success).toBe(true);
+  });
+
+  it('every KNOWN_FRAME_TYPES entry has a discriminated branch', () => {
+    // Probe each known type by attempting a minimal valid construction.
+    // Failure here means the union and the KNOWN_FRAME_TYPES list drifted.
+    for (const type of KNOWN_FRAME_TYPES) {
+      const probe = WsFrameSchema.safeParse({ type, __dummy__: true });
+      // We expect FAILURE on every type because we're missing required fields,
+      // but the failure must be ABOUT the missing fields, not about an unknown
+      // type. A "Invalid discriminator value" error means the type isn't in
+      // the union — that's a drift.
+      if (probe.success) continue;
+      const issues = probe.error.issues;
+      const hasInvalidDiscriminator = issues.some(
+        (i) => i.code === 'invalid_union_discriminator',
+      );
+      expect(hasInvalidDiscriminator, `frame type '${type}' is missing from the discriminated union`).toBe(false);
+    }
+  });
+});
+
+describe('ws-frames.ts file mirror parity', () => {
+  it('apps/server and apps/web copies are byte-identical', () => {
+    const here = fileURLToPath(import.meta.url);
+    const serverPath = resolve(here, '../../../types/ws-frames.ts');
+    const webPath = resolve(here, '../../../../../web/src/api/ws-frames.ts');
+    const serverContent = readFileSync(serverPath, 'utf8');
+    const webContent = readFileSync(webPath, 'utf8');
+    expect(webContent, 'apps/web/src/api/ws-frames.ts must be byte-identical to apps/server/src/types/ws-frames.ts').toBe(serverContent);
+  });
+});
+
+describe('broker.publishFrame / publishUserFrame fail-closed behavior', () => {
+  let logErrors: Array<{ obj: unknown; msg: string }>;
+  let mockLog: Parameters<typeof createBroker>[0];
+
+  beforeEach(() => {
+    logErrors = [];
+    mockLog = {
+      error: (obj: unknown, msg: string) => {
+        logErrors.push({ obj, msg });
+      },
+      info: () => {},
+      warn: () => {},
+      debug: () => {},
+      trace: () => {},
+      fatal: () => {},
+      child: () => mockLog as never,
+      level: 'info',
+      silent: () => {},
+    } as unknown as Parameters<typeof createBroker>[0];
+  });
+
+  afterEach(() => {
+    vi.restoreAllMocks();
+  });
+
+  it('publishFrame delivers a valid frame to subscribers', () => {
+    const broker = createBroker(mockLog);
+    const received: WsFrame[] = [];
+    broker.subscribe('sess-1', (f) => received.push(f as WsFrame));
+    broker.publishFrame('sess-1', {
+      type: 'delta',
+      message_id: VALID_UUID_A,
+      chat_id: VALID_UUID_B,
+      content: 'hello',
+    });
+    expect(received).toHaveLength(1);
+    expect((received[0] as { type: string }).type).toBe('delta');
+    expect(logErrors).toHaveLength(0);
+  });
+
+  it('publishFrame drops + logs an invalid frame instead of delivering it', () => {
+    const broker = createBroker(mockLog);
+    const received: WsFrame[] = [];
+    broker.subscribe('sess-1', (f) => received.push(f as WsFrame));
+    broker.publishFrame('sess-1', {
+      type: 'delta',
+      message_id: 'not-a-uuid',
+      content: 'hello',
+    } as never);
+    expect(received).toHaveLength(0);
+    expect(logErrors).toHaveLength(1);
+    expect(logErrors[0]!.msg).toMatch(/ws-frame-validation-failed/);
+  });
+
+  it('publishUserFrame drops + logs an invalid user-channel frame', () => {
+    const broker = createBroker(mockLog);
+    const received: WsFrame[] = [];
+    broker.subscribeUser('default', (f) => received.push(f as WsFrame));
+    broker.publishUserFrame('default', {
+      type: 'chat_status',
+      chat_id: VALID_UUID_A,
+      status: 'working', // v1.12.1 dropped this enum value
+      at: VALID_TIMESTAMP,
+    } as never);
+    expect(received).toHaveLength(0);
+    expect(logErrors).toHaveLength(1);
+  });
+
+  it('publishFrame validation failure does not throw (no cascade into stream-phase)', () => {
+    const broker = createBroker(mockLog);
+    expect(() =>
+      broker.publishFrame('sess-1', { type: 'unknown_type' } as never),
+    ).not.toThrow();
+  });
+});

apps/server/src/services/broker.ts

@@ -1,3 +1,6 @@
+import type { FastifyBaseLogger } from 'fastify';
+import { WsFrameSchema, type WsFrame } from '../types/ws-frames.js';
+
 export type Frame = Record<string, unknown> & { type: string };
 export type Listener = (frame: Frame) => void;
 
@@ -6,9 +9,15 @@ export interface Broker {
   subscribe(sessionId: string, listener: Listener): () => void;
   publishUser(user: string, frame: Frame): void;
   subscribeUser(user: string, listener: Listener): () => void;
+  // v1.13.11-a: typed publish wrappers. Validate against WsFrameSchema and
+  // delegate to publish / publishUser on success; log + drop on failure
+  // (fail-closed). Existing publish / publishUser callers stay legal — they
+  // get converted to the typed variant in v1.13.11-b.
+  publishFrame(sessionId: string, frame: WsFrame): void;
+  publishUserFrame(user: string, frame: WsFrame): void;
 }
 
-export function createBroker(): Broker {
+export function createBroker(log?: FastifyBaseLogger): Broker {
   const topics = new Map<string, Set<Listener>>();
   const userTopics = new Map<string, Set<Listener>>();
 
@@ -39,6 +48,28 @@ export function createBroker(): Broker {
     };
   }
 
+  // v1.13.11-a: shared validation guard. Returns the parsed/typed frame on
+  // success, or null on failure (after logging). Brief mandates fail-closed
+  // semantics: invalid frames don't reach subscribers; throwing here could
+  // cascade into stream-phase aborts which v1.13.7 already had to defend
+  // against, so log + drop is the right shape.
+  function validate(channel: 'session' | 'user', key: string, frame: WsFrame): WsFrame | null {
+    const parsed = WsFrameSchema.safeParse(frame);
+    if (parsed.success) return parsed.data;
+    const frameType = (frame as { type?: unknown })?.type;
+    const errors = parsed.error.flatten();
+    if (log) {
+      log.error(
+        { channel, key, frame_type: frameType, errors },
+        'ws-frame-validation-failed: dropping invalid frame',
+      );
+    } else {
+      // Fallback for callers that didn't pass a logger (e.g. unit tests).
+      console.error('ws-frame-validation-failed', { channel, key, frame_type: frameType, errors });
+    }
+    return null;
+  }
+
   return {
     publish(sessionId, frame) {
       publishTo(topics, sessionId, frame);
@@ -52,5 +83,15 @@ export function createBroker(): Broker {
     subscribeUser(user, listener) {
       return subscribeTo(userTopics, user, listener);
     },
+    publishFrame(sessionId, frame) {
+      const valid = validate('session', sessionId, frame);
+      if (!valid) return;
+      publishTo(topics, sessionId, valid as Frame);
+    },
+    publishUserFrame(user, frame) {
+      const valid = validate('user', user, frame);
+      if (!valid) return;
+      publishTo(userTopics, user, valid as Frame);
+    },
   };
 }

apps/server/src/services/compaction.ts

@@ -431,15 +431,16 @@ export async function process(input: ProcessInput): Promise<void> {
     'compaction: invoking model',
   );
 
-  // 6a. Flip the chat dot amber for the duration of the LLM call + DB writes.
-  // Same { type: 'chat_status', status: 'working', at } shape inference.ts
-  // emits at runner enqueue. publishUser → broadcasts on the per-user channel
-  // (all devices / tabs see it) since chat_status is a user-channel frame in
-  // BooCode (see useChatStatus.ts, which is the consumer).
-  broker.publishUser('default', {
+  // 6a. Flip the chat dot for the duration of the LLM call + DB writes.
+  // v1.13.11-b: publish status='streaming' (the v1.12.1-widened replacement
+  // for the dropped 'working' value). Compaction's LLM call has the same
+  // semantic as an inference turn for dot-state purposes. The v1.12.1
+  // chat_status widening missed this site; v1.13.11's WsFrame Zod schema
+  // surfaced the drift via the unknown-enum-value check.
+  broker.publishUserFrame('default', {
     type: 'chat_status',
     chat_id: chatId,
-    status: 'working',
+    status: 'streaming',
     at: new Date().toISOString(),
   });
 
@@ -508,7 +509,7 @@ export async function process(input: ProcessInput): Promise<void> {
     // Always restore the dot. Status='idle' (not 'error') even on failure —
     // the caller logs/re-surfaces the error separately; the dot doesn't
     // need to stay red across reloads for a transient compaction blip.
-    broker.publishUser('default', {
+    broker.publishUserFrame('default', {
       type: 'chat_status',
       chat_id: chatId,
       status: 'idle',
@@ -522,7 +523,7 @@ export async function process(input: ProcessInput): Promise<void> {
   // toast. Order matters: idle must precede 'compacted' so the dot is
   // already green by the time the refetch toast appears.
   if (succeeded) {
-    broker.publish(sessionId, {
+    broker.publishFrame(sessionId, {
       type: 'compacted',
       session_id: sessionId,
       chat_id: chatId,

apps/server/src/types/ws-frames.ts

@@ -0,0 +1,318 @@
+// v1.13.11-a: Zod schemas for every WebSocket frame published by the server.
+// Validation runs both on send (broker.publishFrame / publishUserFrame) and
+// on receive (apps/web/src/hooks/useSessionStream + useUserEvents). Catches
+// silent protocol drift between publisher and consumer.
+//
+// IMPORTANT: This file is duplicated byte-identical at
+// apps/web/src/api/ws-frames.ts. The two apps have separate tsconfigs and
+// no path alias; the duplication is sync-by-hand. A test asserts the two
+// files match. If you change one, change the other.
+//
+// Per-kind payload schemas (tool_call args, message_parts payloads, etc.)
+// stay z.unknown() in v1.13.11. Frame-level drift detection is the goal;
+// deep payload validation is follow-up work.
+
+import { z } from 'zod';
+
+// ---- shared primitives -----------------------------------------------------
+
+const Uuid = z.string().uuid();
+// Tool call IDs are model-emitted (e.g. "call_abc123") — not UUIDs.
+const ToolCallId = z.string().min(1);
+const IsoTimestamp = z.string().min(1);
+
+const ChatStatusValue = z.enum([
+  'streaming',
+  'tool_running',
+  'waiting_for_input',
+  'idle',
+  'error',
+]);
+
+const ErrorReasonValue = z.enum([
+  'llm_provider_error',
+  'doom_loop',
+  'doom_loop_summary_failed',
+  'cap_hit',
+  'cap_hit_summary_failed',
+]);
+
+const MessageRoleValue = z.enum(['user', 'assistant', 'system', 'tool']);
+
+const ToolCallShape = z.object({
+  id: ToolCallId,
+  name: z.string().min(1),
+  args: z.record(z.string(), z.unknown()),
+});
+
+// Free-form bags: opaque to the frame schema; deep validation is out of
+// scope for v1.13.11 (frame-level drift detection is the goal; per-kind
+// payload narrowing is follow-up work). z.unknown() means the consumer
+// must narrow before reading — TypeScript-side this is fine because every
+// consumer already operates on the hand-maintained Project / Chat / Session
+// / WorkspacePane types (the brief's "Don't strip existing types yet"
+// rule), and the Zod-typed shape is only used at the publishFrame boundary.
+const OpaqueObject = z.unknown();
+
+// ---- per-session channel frames --------------------------------------------
+
+export const SnapshotFrame = z.object({
+  type: z.literal('snapshot'),
+  messages: z.array(OpaqueObject),
+});
+
+export const MessageStartedFrame = z.object({
+  type: z.literal('message_started'),
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  role: MessageRoleValue,
+});
+
+export const DeltaFrame = z.object({
+  type: z.literal('delta'),
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  content: z.string(),
+});
+
+export const ToolCallFrame = z.object({
+  type: z.literal('tool_call'),
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  tool_call: ToolCallShape,
+});
+
+export const ToolResultFrame = z.object({
+  type: z.literal('tool_result'),
+  tool_message_id: Uuid,
+  chat_id: Uuid.optional(),
+  tool_call_id: ToolCallId,
+  output: z.unknown(),
+  truncated: z.boolean(),
+  error: z.string().optional(),
+});
+
+export const MessageCompleteFrame = z.object({
+  type: z.literal('message_complete'),
+  message_id: Uuid,
+  chat_id: Uuid.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(),
+  started_at: IsoTimestamp.nullable().optional(),
+  finished_at: IsoTimestamp.nullable().optional(),
+  model: z.string().optional(),
+  metadata: OpaqueObject.nullable().optional(),
+});
+
+export const UsageFrame = z.object({
+  type: z.literal('usage'),
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  completion_tokens: z.number().int().nonnegative().nullable(),
+  ctx_used: z.number().int().nonnegative().nullable(),
+  ctx_max: z.number().int().positive().nullable(),
+});
+
+export const MessagesDeletedFrame = z.object({
+  type: z.literal('messages_deleted'),
+  message_ids: z.array(Uuid),
+  chat_id: Uuid.optional(),
+});
+
+export const ChatRenamedFrame = z.object({
+  type: z.literal('chat_renamed'),
+  chat_id: Uuid,
+  name: z.string(),
+});
+
+export const CompactedFrame = z.object({
+  type: z.literal('compacted'),
+  session_id: Uuid,
+  chat_id: Uuid,
+  summary_message_id: Uuid,
+});
+
+export const ErrorFrame = z.object({
+  type: z.literal('error'),
+  message_id: Uuid.optional(),
+  chat_id: Uuid.optional(),
+  error: z.string(),
+  reason: ErrorReasonValue.optional(),
+});
+
+// ---- per-user channel frames (sidebar refresh) -----------------------------
+
+export const ChatStatusFrame = z.object({
+  type: z.literal('chat_status'),
+  chat_id: Uuid,
+  status: ChatStatusValue,
+  at: IsoTimestamp,
+  reason: ErrorReasonValue.optional(),
+});
+
+export const SessionUpdatedFrame = z.object({
+  type: z.literal('session_updated'),
+  session_id: Uuid,
+  project_id: Uuid,
+  name: z.string(),
+  updated_at: IsoTimestamp,
+});
+
+export const SessionRenamedFrame = z.object({
+  type: z.literal('session_renamed'),
+  session_id: Uuid,
+  name: z.string(),
+});
+
+export const SessionCreatedFrame = z.object({
+  type: z.literal('session_created'),
+  session: OpaqueObject,
+  project_id: Uuid,
+});
+
+export const SessionArchivedFrame = z.object({
+  type: z.literal('session_archived'),
+  session_id: Uuid,
+  project_id: Uuid,
+});
+
+export const SessionDeletedFrame = z.object({
+  type: z.literal('session_deleted'),
+  session_id: Uuid,
+  project_id: Uuid,
+});
+
+export const SessionWorkspaceUpdatedFrame = z.object({
+  type: z.literal('session_workspace_updated'),
+  session_id: Uuid,
+  workspace_panes: z.array(OpaqueObject),
+});
+
+export const ChatCreatedFrame = z.object({
+  type: z.literal('chat_created'),
+  chat: OpaqueObject,
+  session_id: Uuid,
+});
+
+export const ChatUpdatedFrame = z.object({
+  type: z.literal('chat_updated'),
+  chat_id: Uuid,
+  session_id: Uuid,
+  name: z.string().nullable(),
+  updated_at: IsoTimestamp,
+});
+
+export const ChatArchivedFrame = z.object({
+  type: z.literal('chat_archived'),
+  chat_id: Uuid,
+  session_id: Uuid,
+});
+
+export const ChatUnarchivedFrame = z.object({
+  type: z.literal('chat_unarchived'),
+  chat: OpaqueObject,
+});
+
+export const ChatDeletedFrame = z.object({
+  type: z.literal('chat_deleted'),
+  chat_id: Uuid,
+  session_id: Uuid,
+});
+
+export const ProjectCreatedFrame = z.object({
+  type: z.literal('project_created'),
+  project: OpaqueObject,
+});
+
+export const ProjectArchivedFrame = z.object({
+  type: z.literal('project_archived'),
+  project_id: Uuid,
+});
+
+export const ProjectUnarchivedFrame = z.object({
+  type: z.literal('project_unarchived'),
+  project: OpaqueObject,
+});
+
+export const ProjectUpdatedFrame = z.object({
+  type: z.literal('project_updated'),
+  project_id: Uuid,
+  name: z.string(),
+});
+
+export const ProjectDeletedFrame = z.object({
+  type: z.literal('project_deleted'),
+  project_id: Uuid,
+});
+
+// ---- discriminated union ---------------------------------------------------
+
+export const WsFrameSchema = z.discriminatedUnion('type', [
+  // per-session
+  SnapshotFrame,
+  MessageStartedFrame,
+  DeltaFrame,
+  ToolCallFrame,
+  ToolResultFrame,
+  MessageCompleteFrame,
+  UsageFrame,
+  MessagesDeletedFrame,
+  ChatRenamedFrame,
+  CompactedFrame,
+  ErrorFrame,
+  // per-user
+  ChatStatusFrame,
+  SessionUpdatedFrame,
+  SessionRenamedFrame,
+  SessionCreatedFrame,
+  SessionArchivedFrame,
+  SessionDeletedFrame,
+  SessionWorkspaceUpdatedFrame,
+  ChatCreatedFrame,
+  ChatUpdatedFrame,
+  ChatArchivedFrame,
+  ChatUnarchivedFrame,
+  ChatDeletedFrame,
+  ProjectCreatedFrame,
+  ProjectArchivedFrame,
+  ProjectUnarchivedFrame,
+  ProjectUpdatedFrame,
+  ProjectDeletedFrame,
+]);
+
+export type WsFrame = z.infer<typeof WsFrameSchema>;
+
+// Convenience: the set of known frame types. Useful for the publishFrame
+// helper to log the offending type name when validation fails. Kept in sync
+// by hand with the discriminated union above.
+export const KNOWN_FRAME_TYPES: readonly WsFrame['type'][] = [
+  'snapshot',
+  'message_started',
+  'delta',
+  'tool_call',
+  'tool_result',
+  'message_complete',
+  'usage',
+  'messages_deleted',
+  'chat_renamed',
+  'compacted',
+  'error',
+  'chat_status',
+  'session_updated',
+  'session_renamed',
+  'session_created',
+  'session_archived',
+  'session_deleted',
+  'session_workspace_updated',
+  'chat_created',
+  'chat_updated',
+  'chat_archived',
+  'chat_unarchived',
+  'chat_deleted',
+  'project_created',
+  'project_archived',
+  'project_unarchived',
+  'project_updated',
+  'project_deleted',
+] as const;

apps/web/package.json

@@ -31,7 +31,8 @@
     "shiki": "^1.29.2",
     "sonner": "^2.0.7",
     "tailwind-merge": "^3.6.0",
-    "tw-animate-css": "^1.4.0"
+    "tw-animate-css": "^1.4.0",
+    "zod": "^3.23.8"
   },
   "devDependencies": {
     "@tailwindcss/postcss": "^4.3.0",

apps/web/src/api/ws-frames.ts

@@ -0,0 +1,318 @@
+// v1.13.11-a: Zod schemas for every WebSocket frame published by the server.
+// Validation runs both on send (broker.publishFrame / publishUserFrame) and
+// on receive (apps/web/src/hooks/useSessionStream + useUserEvents). Catches
+// silent protocol drift between publisher and consumer.
+//
+// IMPORTANT: This file is duplicated byte-identical at
+// apps/web/src/api/ws-frames.ts. The two apps have separate tsconfigs and
+// no path alias; the duplication is sync-by-hand. A test asserts the two
+// files match. If you change one, change the other.
+//
+// Per-kind payload schemas (tool_call args, message_parts payloads, etc.)
+// stay z.unknown() in v1.13.11. Frame-level drift detection is the goal;
+// deep payload validation is follow-up work.
+
+import { z } from 'zod';
+
+// ---- shared primitives -----------------------------------------------------
+
+const Uuid = z.string().uuid();
+// Tool call IDs are model-emitted (e.g. "call_abc123") — not UUIDs.
+const ToolCallId = z.string().min(1);
+const IsoTimestamp = z.string().min(1);
+
+const ChatStatusValue = z.enum([
+  'streaming',
+  'tool_running',
+  'waiting_for_input',
+  'idle',
+  'error',
+]);
+
+const ErrorReasonValue = z.enum([
+  'llm_provider_error',
+  'doom_loop',
+  'doom_loop_summary_failed',
+  'cap_hit',
+  'cap_hit_summary_failed',
+]);
+
+const MessageRoleValue = z.enum(['user', 'assistant', 'system', 'tool']);
+
+const ToolCallShape = z.object({
+  id: ToolCallId,
+  name: z.string().min(1),
+  args: z.record(z.string(), z.unknown()),
+});
+
+// Free-form bags: opaque to the frame schema; deep validation is out of
+// scope for v1.13.11 (frame-level drift detection is the goal; per-kind
+// payload narrowing is follow-up work). z.unknown() means the consumer
+// must narrow before reading — TypeScript-side this is fine because every
+// consumer already operates on the hand-maintained Project / Chat / Session
+// / WorkspacePane types (the brief's "Don't strip existing types yet"
+// rule), and the Zod-typed shape is only used at the publishFrame boundary.
+const OpaqueObject = z.unknown();
+
+// ---- per-session channel frames --------------------------------------------
+
+export const SnapshotFrame = z.object({
+  type: z.literal('snapshot'),
+  messages: z.array(OpaqueObject),
+});
+
+export const MessageStartedFrame = z.object({
+  type: z.literal('message_started'),
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  role: MessageRoleValue,
+});
+
+export const DeltaFrame = z.object({
+  type: z.literal('delta'),
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  content: z.string(),
+});
+
+export const ToolCallFrame = z.object({
+  type: z.literal('tool_call'),
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  tool_call: ToolCallShape,
+});
+
+export const ToolResultFrame = z.object({
+  type: z.literal('tool_result'),
+  tool_message_id: Uuid,
+  chat_id: Uuid.optional(),
+  tool_call_id: ToolCallId,
+  output: z.unknown(),
+  truncated: z.boolean(),
+  error: z.string().optional(),
+});
+
+export const MessageCompleteFrame = z.object({
+  type: z.literal('message_complete'),
+  message_id: Uuid,
+  chat_id: Uuid.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(),
+  started_at: IsoTimestamp.nullable().optional(),
+  finished_at: IsoTimestamp.nullable().optional(),
+  model: z.string().optional(),
+  metadata: OpaqueObject.nullable().optional(),
+});
+
+export const UsageFrame = z.object({
+  type: z.literal('usage'),
+  message_id: Uuid,
+  chat_id: Uuid.optional(),
+  completion_tokens: z.number().int().nonnegative().nullable(),
+  ctx_used: z.number().int().nonnegative().nullable(),
+  ctx_max: z.number().int().positive().nullable(),
+});
+
+export const MessagesDeletedFrame = z.object({
+  type: z.literal('messages_deleted'),
+  message_ids: z.array(Uuid),
+  chat_id: Uuid.optional(),
+});
+
+export const ChatRenamedFrame = z.object({
+  type: z.literal('chat_renamed'),
+  chat_id: Uuid,
+  name: z.string(),
+});
+
+export const CompactedFrame = z.object({
+  type: z.literal('compacted'),
+  session_id: Uuid,
+  chat_id: Uuid,
+  summary_message_id: Uuid,
+});
+
+export const ErrorFrame = z.object({
+  type: z.literal('error'),
+  message_id: Uuid.optional(),
+  chat_id: Uuid.optional(),
+  error: z.string(),
+  reason: ErrorReasonValue.optional(),
+});
+
+// ---- per-user channel frames (sidebar refresh) -----------------------------
+
+export const ChatStatusFrame = z.object({
+  type: z.literal('chat_status'),
+  chat_id: Uuid,
+  status: ChatStatusValue,
+  at: IsoTimestamp,
+  reason: ErrorReasonValue.optional(),
+});
+
+export const SessionUpdatedFrame = z.object({
+  type: z.literal('session_updated'),
+  session_id: Uuid,
+  project_id: Uuid,
+  name: z.string(),
+  updated_at: IsoTimestamp,
+});
+
+export const SessionRenamedFrame = z.object({
+  type: z.literal('session_renamed'),
+  session_id: Uuid,
+  name: z.string(),
+});
+
+export const SessionCreatedFrame = z.object({
+  type: z.literal('session_created'),
+  session: OpaqueObject,
+  project_id: Uuid,
+});
+
+export const SessionArchivedFrame = z.object({
+  type: z.literal('session_archived'),
+  session_id: Uuid,
+  project_id: Uuid,
+});
+
+export const SessionDeletedFrame = z.object({
+  type: z.literal('session_deleted'),
+  session_id: Uuid,
+  project_id: Uuid,
+});
+
+export const SessionWorkspaceUpdatedFrame = z.object({
+  type: z.literal('session_workspace_updated'),
+  session_id: Uuid,
+  workspace_panes: z.array(OpaqueObject),
+});
+
+export const ChatCreatedFrame = z.object({
+  type: z.literal('chat_created'),
+  chat: OpaqueObject,
+  session_id: Uuid,
+});
+
+export const ChatUpdatedFrame = z.object({
+  type: z.literal('chat_updated'),
+  chat_id: Uuid,
+  session_id: Uuid,
+  name: z.string().nullable(),
+  updated_at: IsoTimestamp,
+});
+
+export const ChatArchivedFrame = z.object({
+  type: z.literal('chat_archived'),
+  chat_id: Uuid,
+  session_id: Uuid,
+});
+
+export const ChatUnarchivedFrame = z.object({
+  type: z.literal('chat_unarchived'),
+  chat: OpaqueObject,
+});
+
+export const ChatDeletedFrame = z.object({
+  type: z.literal('chat_deleted'),
+  chat_id: Uuid,
+  session_id: Uuid,
+});
+
+export const ProjectCreatedFrame = z.object({
+  type: z.literal('project_created'),
+  project: OpaqueObject,
+});
+
+export const ProjectArchivedFrame = z.object({
+  type: z.literal('project_archived'),
+  project_id: Uuid,
+});
+
+export const ProjectUnarchivedFrame = z.object({
+  type: z.literal('project_unarchived'),
+  project: OpaqueObject,
+});
+
+export const ProjectUpdatedFrame = z.object({
+  type: z.literal('project_updated'),
+  project_id: Uuid,
+  name: z.string(),
+});
+
+export const ProjectDeletedFrame = z.object({
+  type: z.literal('project_deleted'),
+  project_id: Uuid,
+});
+
+// ---- discriminated union ---------------------------------------------------
+
+export const WsFrameSchema = z.discriminatedUnion('type', [
+  // per-session
+  SnapshotFrame,
+  MessageStartedFrame,
+  DeltaFrame,
+  ToolCallFrame,
+  ToolResultFrame,
+  MessageCompleteFrame,
+  UsageFrame,
+  MessagesDeletedFrame,
+  ChatRenamedFrame,
+  CompactedFrame,
+  ErrorFrame,
+  // per-user
+  ChatStatusFrame,
+  SessionUpdatedFrame,
+  SessionRenamedFrame,
+  SessionCreatedFrame,
+  SessionArchivedFrame,
+  SessionDeletedFrame,
+  SessionWorkspaceUpdatedFrame,
+  ChatCreatedFrame,
+  ChatUpdatedFrame,
+  ChatArchivedFrame,
+  ChatUnarchivedFrame,
+  ChatDeletedFrame,
+  ProjectCreatedFrame,
+  ProjectArchivedFrame,
+  ProjectUnarchivedFrame,
+  ProjectUpdatedFrame,
+  ProjectDeletedFrame,
+]);
+
+export type WsFrame = z.infer<typeof WsFrameSchema>;
+
+// Convenience: the set of known frame types. Useful for the publishFrame
+// helper to log the offending type name when validation fails. Kept in sync
+// by hand with the discriminated union above.
+export const KNOWN_FRAME_TYPES: readonly WsFrame['type'][] = [
+  'snapshot',
+  'message_started',
+  'delta',
+  'tool_call',
+  'tool_result',
+  'message_complete',
+  'usage',
+  'messages_deleted',
+  'chat_renamed',
+  'compacted',
+  'error',
+  'chat_status',
+  'session_updated',
+  'session_renamed',
+  'session_created',
+  'session_archived',
+  'session_deleted',
+  'session_workspace_updated',
+  'chat_created',
+  'chat_updated',
+  'chat_archived',
+  'chat_unarchived',
+  'chat_deleted',
+  'project_created',
+  'project_archived',
+  'project_unarchived',
+  'project_updated',
+  'project_deleted',
+] as const;

apps/web/src/hooks/useSessionStream.ts

@@ -1,6 +1,7 @@
 import { useEffect, useRef, useState } from 'react';
 import { toast } from 'sonner';
 import type { Message, WsFrame } from '@/api/types';
+import { WsFrameSchema } from '@/api/ws-frames';
 import { api } from '@/api/client';
 import { sessionEvents } from './sessionEvents';
 import { recordUsage } from './useChatThroughput';
@@ -216,8 +217,28 @@ export function useSessionStream(sessionId: string | undefined) {
         setState((s) => ({ ...s, connected: true, error: null }));
       };
       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 {
-          const frame = JSON.parse(typeof ev.data === 'string' ? ev.data : '') as WsFrame;
+          raw = JSON.parse(typeof ev.data === 'string' ? ev.data : '');
+        } catch (err) {
+          console.warn('bad ws frame (parse)', err);
+          return;
+        }
+        const validated = WsFrameSchema.safeParse(raw);
+        if (!validated.success) {
+          console.error('ws-frame-validation-failed (session channel)', {
+            frame_type: (raw as { type?: unknown })?.type,
+            errors: validated.error.flatten(),
+          });
+          return;
+        }
+        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
           // rows render correctly. We dispatch the fresh list as a synthetic

apps/web/src/hooks/useUserEvents.ts

@@ -1,4 +1,5 @@
 import { useEffect } from 'react';
+import { WsFrameSchema } from '@/api/ws-frames';
 import { sessionEvents } from './sessionEvents';
 import { createWsReconnectToast } from './wsReconnectToast';
 
@@ -38,14 +39,33 @@ export function useUserEvents(): void {
       };
 
       ws.onmessage = (ev) => {
+        // v1.13.11-a: Zod-validate every inbound frame. Fail-closed — invalid
+        // frames are logged and dropped instead of dispatched onto the
+        // sessionEvents bus where a stale or wrong shape would silently
+        // corrupt sidebar / chat state.
+        let raw: unknown;
         try {
-          const parsed: unknown = JSON.parse(ev.data);
-          if (parsed && typeof (parsed as { type?: unknown }).type === 'string') {
-            sessionEvents.emit(parsed as import('./sessionEvents').SessionEvent);
-          }
+          raw = JSON.parse(ev.data);
         } catch (err) {
           console.warn('useUserEvents: failed to parse frame', err);
+          return;
         }
+        const validated = WsFrameSchema.safeParse(raw);
+        if (!validated.success) {
+          console.error('ws-frame-validation-failed (user channel)', {
+            frame_type: (raw as { type?: unknown })?.type,
+            errors: validated.error.flatten(),
+          });
+          return;
+        }
+        // Bridge cast: Zod's union is broader than SessionEvent (it includes
+        // per-session-channel frames too, which never arrive on the user
+        // channel). sessionEvents.emit only dispatches frames whose type
+        // appears in SessionEvent; the narrowing happens via the existing
+        // useSidebar.ts applyEvent switch.
+        sessionEvents.emit(
+          validated.data as unknown as import('./sessionEvents').SessionEvent,
+        );
       };
 
       ws.onclose = () => {

pnpm-lock.yaml

@@ -157,6 +157,9 @@ importers:
       tw-animate-css:
         specifier: ^1.4.0
         version: 1.4.0
+      zod:
+        specifier: ^3.23.8
+        version: 3.25.76
     devDependencies:
       '@tailwindcss/postcss':
         specifier: ^4.3.0