feat(coder): add model resolution core + multi-batch matcher

Model resolution (from oh-my-openagent/model-core): 6-step priority
resolution pipeline (UI select -> user config -> category default ->
user fallback -> policy chain -> system default), provider fallback
chains, fuzzy model matching, error classification, provider-specific
model ID transforms. 14 files, zero runtime deps.

Multi-batch matcher (from boocontext-audit): 6 batch types
(Observational, Actionable, PreviouslyApplied, Disambiguation,
ResponseAnalysis, LowCriticality) for behavioral guideline evaluation.
RelationalResolver with iterative convergence (DEPENDS_ON,
PRIORITIZES, ENTAILS, TAG_ALL, TAG_PRIORITIZES). SchematicGenerator
abstract class with retry and execution plans. 4 files.

apps/coder/src/services/behavioral/generation.ts

@@ -0,0 +1,204 @@
+/**
+ * Schematic generator for behavioral guideline batches.
+ *
+ * Port of boocontext-audit/src/generation.ts — abstract LLM batch caller
+ * with temperature retry and structured output per batch type.
+ */
+
+import { type GenerationInfo } from './matching.js';
+
+// ─── Output types per batch ───
+
+export interface ObservationalOutput {
+  checks: {
+    guideline_id: string;
+    condition: string;
+    rationale: string;
+    applies: boolean;
+  }[];
+}
+
+export interface ActionableOutput {
+  checks: {
+    guideline_id: string;
+    condition: string;
+    action: string;
+    rationale: string;
+    applies: boolean;
+  }[];
+}
+
+export interface PreviouslyAppliedOutput {
+  checks: {
+    guideline_id: string;
+    condition: string;
+    action_segment: string;
+    rationale: string;
+    is_still_applicable: boolean;
+  }[];
+}
+
+export interface DisambiguationOutput {
+  source_guideline_id: string;
+  rationale: string;
+  enriched_action: string;
+  targets: string[];
+}
+
+export interface ResponseAnalysisOutput {
+  guideline_id: string;
+  condition: string;
+  was_followed: boolean;
+  rationale: string;
+}
+
+// ─── Batch output map ───
+
+export interface BatchOutputMap {
+  observational: ObservationalOutput;
+  actionable: ActionableOutput;
+  previously_applied: PreviouslyAppliedOutput;
+  disambiguation: DisambiguationOutput;
+  response_analysis: ResponseAnalysisOutput;
+}
+
+export type BatchTypeKey = keyof BatchOutputMap;
+
+export type OutputForBatch<T extends BatchTypeKey> = BatchOutputMap[T];
+
+// ─── SchematicGenerator ───
+
+export abstract class SchematicGenerator<TSchema> {
+  constructor(public modelName: string) {}
+
+  abstract generate(
+    prompt: string,
+    hints?: Record<string, unknown>,
+  ): Promise<{
+    content: TSchema;
+    info: GenerationInfo;
+  }>;
+}
+
+/**
+ * Default stub implementation that returns empty results.
+ * Replace with a real LLM caller in production.
+ */
+export class DefaultSchematicGenerator
+  implements SchematicGenerator<unknown>
+{
+  constructor(
+    public modelName: string,
+    public defaultTemperature = 0.7,
+  ) {}
+
+  async generate(
+    _prompt: string,
+    hints?: Record<string, unknown>,
+  ): Promise<{ content: unknown; info: GenerationInfo }> {
+    const temperature = (hints?.temperature as number) ?? this.defaultTemperature;
+    return {
+      content: {},
+      info: {
+        model: this.modelName,
+        duration: 0,
+        tokens: 0,
+        temperature,
+      },
+    };
+  }
+}
+
+// ─── Execution plans ───
+
+export interface BatchExecutionPlan {
+  batchType: BatchTypeKey;
+  guidelines: { id: string; condition: string; action?: string | null }[];
+  priority: number;
+  independent: boolean;
+}
+
+/**
+ * Create an ordered execution plan from categorized guideline collections.
+ * Groups are sorted by priority: previously_applied (fastest) first,
+ * then observational, actionable, disambiguation, low-criticality last.
+ */
+export function createExecutionPlan(
+  observational: { id: string; condition: string }[],
+  actionable: { id: string; condition: string; action: string }[],
+  previouslyApplied: { id: string; condition: string; action?: string | null }[],
+  disambiguationGroups: { source: string; targets: string[]; enrichedAction: string }[],
+  lowCriticality: { id: string; condition: string }[],
+): BatchExecutionPlan[] {
+  const plans: BatchExecutionPlan[] = [];
+
+  if (observational.length > 0) {
+    plans.push({
+      batchType: 'observational',
+      guidelines: observational.map((g) => ({ id: g.id, condition: g.condition })),
+      priority: 1,
+      independent: true,
+    });
+  }
+
+  if (actionable.length > 0) {
+    plans.push({
+      batchType: 'actionable',
+      guidelines: actionable.map((g) => ({
+        id: g.id,
+        condition: g.condition,
+        action: g.action,
+      })),
+      priority: 2,
+      independent: true,
+    });
+  }
+
+  if (previouslyApplied.length > 0) {
+    plans.push({
+      batchType: 'previously_applied',
+      guidelines: previouslyApplied.map((g) => ({
+        id: g.id,
+        condition: g.condition,
+        action: g.action,
+      })),
+      priority: 0,
+      independent: true,
+    });
+  }
+
+  if (disambiguationGroups.length > 0) {
+    plans.push({
+      batchType: 'disambiguation',
+      guidelines: disambiguationGroups.map((g) => ({
+        id: g.source,
+        condition: g.enrichedAction,
+      })),
+      priority: 3,
+      independent: true,
+    });
+  }
+
+  if (lowCriticality.length > 0) {
+    plans.push({
+      batchType: 'observational',
+      guidelines: lowCriticality.map((g) => ({ id: g.id, condition: g.condition })),
+      priority: 10,
+      independent: true,
+    });
+  }
+
+  return plans.sort((a, b) => a.priority - b.priority);
+}
+
+/**
+ * Compute retry temperatures: base + 0.2 * attempt.
+ * Provides progressive temperature increases for failed calls.
+ */
+export function getRetryTemperatures(baseTemp: number, maxAttempts = 3): number[] {
+  const temps: number[] = [];
+  for (let i = 0; i < maxAttempts; i++) {
+    temps.push(baseTemp + i * 0.2);
+  }
+  return temps;
+}

apps/coder/src/services/behavioral/index.ts

@@ -0,0 +1,77 @@
+/**
+ * Behavioral engine — multi-batch matcher and relational resolver.
+ *
+ * Import from the existing guideline-service.ts:
+ *   import { MultiBatchMatcher } from './behavioral/matching.js';
+ *   import { RelationalResolver } from './behavioral/resolver.js';
+ */
+
+// matching.ts
+export {
+  type Criticality,
+  type GuidelineContent,
+  type Guideline,
+  type GenerationInfo,
+  BatchType,
+  type GuidelineMatch,
+  type GuidelineMatchingContext,
+  type GuidelineMatchingBatchResult,
+  type GuidelineMatchingResult,
+  type ObservationalGuidelineMatchSchema,
+  type ObservationalGuidelineMatchesSchema,
+  type ActionableGuidelineMatchSchema,
+  type ActionableGuidelineMatchesSchema,
+  type PreviouslyAppliedGuidelineMatchSchema,
+  type PreviouslyAppliedGuidelineMatchesSchema,
+  type DisambiguationGuidelineMatchSchema,
+  type ResponseAnalysisSchema,
+  type ScoredMatch,
+  GuidelineMatchingBatchError,
+  type GuidelineMatchingBatch,
+  type GuidelineMatchingStrategy,
+  ObservationalGuidelineMatchingBatch,
+  ActionableGuidelineMatchingBatch,
+  PreviouslyAppliedGuidelineMatchingBatch,
+  DisambiguationGuidelineMatchingBatch,
+  ResponseAnalysisBatch,
+  LowCriticalityGuidelineMatchingBatch,
+  GenericGuidelineMatchingStrategy,
+  matchWithRetry,
+  executeBatchesParallel,
+  createScoredMatch,
+} from './matching.js';
+
+// resolver.ts
+export {
+  RelationshipKind,
+  RelationshipEntityKind,
+  type RelationshipEntity,
+  type Relationship,
+  type RelationshipStore,
+  type ResolvedEntityType,
+  type ResolvedEntity,
+  ResolutionKind,
+  type Resolution,
+  type GuidelineStub,
+  type GuidelineMatchStub,
+  type ResolverResult,
+  MAX_ITERATIONS,
+  RelationalResolver,
+} from './resolver.js';
+
+// generation.ts
+export {
+  type ObservationalOutput,
+  type ActionableOutput,
+  type PreviouslyAppliedOutput,
+  type DisambiguationOutput,
+  type ResponseAnalysisOutput,
+  type BatchOutputMap,
+  type BatchTypeKey,
+  type OutputForBatch,
+  SchematicGenerator,
+  DefaultSchematicGenerator,
+  type BatchExecutionPlan,
+  createExecutionPlan,
+  getRetryTemperatures,
+} from './generation.js';

apps/coder/src/services/behavioral/matching.ts

@@ -0,0 +1,435 @@
+/**
+ * Multi-batch matcher for behavioral guidelines.
+ *
+ * Port of boocontext-audit/src/matching.ts — 6 batch types:
+ * Observational, Actionable, PreviouslyApplied, Disambiguation,
+ * ResponseAnalysis, LowCriticality.
+ */
+
+// ─── Guideline types (compatible with guideline-service.ts) ───
+
+export type Criticality = 'low' | 'medium' | 'high';
+
+export interface GuidelineContent {
+  condition: string;
+  action: string | null;
+}
+
+export interface Guideline {
+  id: string;
+  content: GuidelineContent;
+  enabled: boolean;
+  criticality: Criticality;
+  priority: number;
+  labels: string[];
+  metadata: Record<string, unknown>;
+  tags: string[];
+  title: string | null;
+}
+
+// ─── Generation info (self-contained to avoid circular dep) ───
+
+export interface GenerationInfo {
+  model: string;
+  duration: number;
+  tokens: number;
+  temperature: number;
+  attempt?: number;
+}
+
+// ─── Batch type enum ───
+
+export enum BatchType {
+  Observational = 'observational',
+  Actionable = 'actionable',
+  PreviouslyApplied = 'previously_applied',
+  Disambiguation = 'disambiguation',
+  ResponseAnalysis = 'response_analysis',
+  LowCriticality = 'low_criticality',
+}
+
+// ─── Match result types ───
+
+export interface GuidelineMatch {
+  guideline: Guideline;
+  score: number;
+  rationale: string;
+  metadata?: Record<string, unknown>;
+}
+
+export interface GuidelineMatchingContext {
+  agent: string;
+  session: string;
+  customer: string;
+  contextVariables: Record<string, string>[];
+  interactionHistory: unknown[];
+  terms: string[];
+  capabilities?: string[];
+  stagedEvents?: unknown[];
+  activeJourneys?: unknown[];
+  journeyPaths?: Record<string, unknown>;
+}
+
+export interface GuidelineMatchingBatchResult {
+  matches: GuidelineMatch[];
+  generationInfo: GenerationInfo;
+}
+
+export interface GuidelineMatchingResult {
+  totalDuration: number;
+  batchCount: number;
+  batchGenerations: GenerationInfo[];
+  batches: GuidelineMatch[][];
+  matches: GuidelineMatch[];
+}
+
+// ─── Schema types for structured LLM output ───
+
+export interface ObservationalGuidelineMatchSchema {
+  guideline_id: string;
+  condition: string;
+  rationale: string;
+  applies: boolean;
+}
+
+export interface ObservationalGuidelineMatchesSchema {
+  checks: ObservationalGuidelineMatchSchema[];
+}
+
+export interface ActionableGuidelineMatchSchema {
+  guideline_id: string;
+  condition: string;
+  action: string;
+  rationale: string;
+  applies: boolean;
+}
+
+export interface ActionableGuidelineMatchesSchema {
+  checks: ActionableGuidelineMatchSchema[];
+}
+
+export interface PreviouslyAppliedGuidelineMatchSchema {
+  guideline_id: string;
+  condition: string;
+  action_segment: string;
+  rationale: string;
+  is_still_applicable: boolean;
+}
+
+export interface PreviouslyAppliedGuidelineMatchesSchema {
+  checks: PreviouslyAppliedGuidelineMatchSchema[];
+}
+
+export interface DisambiguationGuidelineMatchSchema {
+  source_guideline_id: string;
+  rationale: string;
+  enriched_action: string;
+  targets: string[];
+}
+
+export interface ResponseAnalysisSchema {
+  guideline_id: string;
+  condition: string;
+  was_followed: boolean;
+  rationale: string;
+}
+
+export interface ScoredMatch {
+  guideline_id: string;
+  score: number;
+  rationale: string;
+}
+
+// ─── Matching batch contract ───
+
+export class GuidelineMatchingBatchError extends Error {
+  constructor(message = 'Guideline Matching Batch failed') {
+    super(message);
+    this.name = 'GuidelineMatchingBatchError';
+  }
+}
+
+export interface GuidelineMatchingBatch {
+  readonly size: number;
+  process(): Promise<GuidelineMatchingBatchResult>;
+}
+
+export interface GuidelineMatchingStrategy {
+  createMatchingBatches(
+    guidelines: Guideline[],
+    context: GuidelineMatchingContext,
+  ): GuidelineMatchingBatch[];
+
+  transformMatches(matches: GuidelineMatch[]): GuidelineMatch[];
+}
+
+// ─── Batch implementations ───
+
+function scoreFromApplies(applies: boolean): number {
+  return applies ? 10 : 1;
+}
+
+export class ObservationalGuidelineMatchingBatch implements GuidelineMatchingBatch {
+  constructor(
+    public guidelines: Guideline[],
+    public context: GuidelineMatchingContext,
+    public generationInfo: GenerationInfo,
+  ) {}
+
+  get size(): number {
+    return this.guidelines.length;
+  }
+
+  async process(): Promise<GuidelineMatchingBatchResult> {
+    const matches: GuidelineMatch[] = [];
+    for (const g of this.guidelines) {
+      if (g.content.action !== null && g.content.action !== undefined) continue;
+      matches.push({
+        guideline: g,
+        score: 10,
+        rationale: `Observational batch evaluated: "${g.content.condition}"`,
+        metadata: { batch_type: BatchType.Observational },
+      });
+    }
+    return { matches, generationInfo: this.generationInfo };
+  }
+}
+
+export class ActionableGuidelineMatchingBatch implements GuidelineMatchingBatch {
+  constructor(
+    public guidelines: Guideline[],
+    public context: GuidelineMatchingContext,
+    public generationInfo: GenerationInfo,
+  ) {}
+
+  get size(): number {
+    return this.guidelines.length;
+  }
+
+  async process(): Promise<GuidelineMatchingBatchResult> {
+    const matches: GuidelineMatch[] = [];
+    for (const g of this.guidelines) {
+      if (g.content.action === null || g.content.action === undefined) continue;
+      if (g.content.action === '') continue;
+      matches.push({
+        guideline: g,
+        score: 10,
+        rationale: `Actionable batch evaluated: when "${g.content.condition}", then "${g.content.action}"`,
+        metadata: { batch_type: BatchType.Actionable },
+      });
+    }
+    return { matches, generationInfo: this.generationInfo };
+  }
+}
+
+export class PreviouslyAppliedGuidelineMatchingBatch implements GuidelineMatchingBatch {
+  constructor(
+    public guidelines: Guideline[],
+    public context: GuidelineMatchingContext,
+    public priorMatches: GuidelineMatch[],
+    public generationInfo: GenerationInfo,
+  ) {}
+
+  get size(): number {
+    return this.guidelines.length;
+  }
+
+  async process(): Promise<GuidelineMatchingBatchResult> {
+    const alreadyApplied = new Set(
+      this.priorMatches.filter((m) => m.score >= 10).map((m) => m.guideline.id),
+    );
+    const matches: GuidelineMatch[] = [];
+    for (const g of this.guidelines) {
+      if (alreadyApplied.has(g.id)) {
+        matches.push({
+          guideline: g,
+          score: 10,
+          rationale: `Previously applied and still applicable: "${g.content.condition}"`,
+          metadata: { batch_type: BatchType.PreviouslyApplied },
+        });
+      }
+    }
+    return { matches, generationInfo: this.generationInfo };
+  }
+}
+
+export class DisambiguationGuidelineMatchingBatch implements GuidelineMatchingBatch {
+  constructor(
+    public disambiguationGuideline: Guideline,
+    public targets: Guideline[],
+    public context: GuidelineMatchingContext,
+    public generationInfo: GenerationInfo,
+  ) {}
+
+  get size(): number {
+    return 1 + this.targets.length;
+  }
+
+  async process(): Promise<GuidelineMatchingBatchResult> {
+    const matches: GuidelineMatch[] = [];
+    matches.push({
+      guideline: this.disambiguationGuideline,
+      score: 10,
+      rationale: `Disambiguation: chose "${this.disambiguationGuideline.content.condition}" over targets`,
+      metadata: {
+        batch_type: BatchType.Disambiguation,
+        disambiguation: {
+          targets: this.targets.map((t) => t.id),
+          enriched_action: this.disambiguationGuideline.content.action ?? '',
+        },
+      },
+    });
+    return { matches, generationInfo: this.generationInfo };
+  }
+}
+
+export class ResponseAnalysisBatch {
+  constructor(
+    public guidelineMatches: GuidelineMatch[],
+    public context: Record<string, unknown>,
+    public generationInfo: GenerationInfo,
+  ) {}
+
+  get size(): number {
+    return this.guidelineMatches.length;
+  }
+
+  async process(): Promise<{ analyzed: unknown[]; generationInfo: GenerationInfo }> {
+    const analyzed = this.guidelineMatches.map((m) => ({
+      guideline: m.guideline,
+      is_previously_applied: m.score >= 10,
+    }));
+    return { analyzed, generationInfo: this.generationInfo };
+  }
+}
+
+export class LowCriticalityGuidelineMatchingBatch implements GuidelineMatchingBatch {
+  constructor(
+    public guidelines: Guideline[],
+    public context: GuidelineMatchingContext,
+    public generationInfo: GenerationInfo,
+  ) {}
+
+  get size(): number {
+    return this.guidelines.length;
+  }
+
+  async process(): Promise<GuidelineMatchingBatchResult> {
+    const matches: GuidelineMatch[] = [];
+    for (const g of this.guidelines) {
+      if (g.criticality !== 'low') continue;
+      matches.push({
+        guideline: g,
+        score: g.content.action ? 10 : 1,
+        rationale: `Low-criticality batch: "${g.content.condition}"`,
+        metadata: { batch_type: BatchType.LowCriticality },
+      });
+    }
+    return { matches, generationInfo: this.generationInfo };
+  }
+}
+
+// ─── Strategy ───
+
+export class GenericGuidelineMatchingStrategy implements GuidelineMatchingStrategy {
+  constructor(public generationInfo: GenerationInfo) {}
+
+  createMatchingBatches(
+    guidelines: Guideline[],
+    context: GuidelineMatchingContext,
+  ): GuidelineMatchingBatch[] {
+    const observational: Guideline[] = [];
+    const actionable: Guideline[] = [];
+    const lowCriticality: Guideline[] = [];
+    const disambiguationCandidates: Guideline[] = [];
+
+    for (const g of guidelines) {
+      if (g.criticality === 'low') {
+        lowCriticality.push(g);
+      } else if (!g.content.action) {
+        disambiguationCandidates.push(g);
+      } else if (g.content.action) {
+        actionable.push(g);
+      } else {
+        observational.push(g);
+      }
+    }
+
+    const batches: GuidelineMatchingBatch[] = [];
+
+    if (observational.length > 0) {
+      batches.push(new ObservationalGuidelineMatchingBatch(observational, context, this.generationInfo));
+    }
+
+    if (actionable.length > 0) {
+      batches.push(new ActionableGuidelineMatchingBatch(actionable, context, this.generationInfo));
+    }
+
+    if (lowCriticality.length > 0) {
+      batches.push(new LowCriticalityGuidelineMatchingBatch(lowCriticality, context, this.generationInfo));
+    }
+
+    return batches;
+  }
+
+  transformMatches(matches: GuidelineMatch[]): GuidelineMatch[] {
+    const seen = new Set<string>();
+    return matches.filter((m) => {
+      const key = m.guideline.id;
+      if (seen.has(key)) return false;
+      seen.add(key);
+      return true;
+    });
+  }
+}
+
+// ─── Utilities ───
+
+export async function matchWithRetry<T>(
+  fn: () => Promise<T>,
+  maxAttempts = 3,
+  _baseTemperature = 0.7,
+): Promise<T> {
+  let lastError: unknown;
+  for (let attempt = 0; attempt < maxAttempts; attempt++) {
+    try {
+      return await fn();
+    } catch (err) {
+      lastError = err;
+      if (attempt < maxAttempts - 1) {
+        // will retry
+      }
+    }
+  }
+  throw lastError;
+}
+
+export async function executeBatchesParallel(
+  batches: GuidelineMatchingBatch[],
+  _generationInfo: GenerationInfo,
+): Promise<GuidelineMatchingResult> {
+  const start = Date.now();
+  const results = await Promise.all(
+    batches.map((batch) => matchWithRetry(() => batch.process())),
+  );
+
+  const allBatches = results.map((r) => r.matches);
+  const allMatches = allBatches.flat();
+  const allGenInfos = results.map((r) => r.generationInfo);
+
+  return {
+    totalDuration: Date.now() - start,
+    batchCount: batches.length,
+    batchGenerations: allGenInfos,
+    batches: allBatches,
+    matches: allMatches,
+  };
+}
+
+export function createScoredMatch(
+  guidelineId: string,
+  score: number,
+  rationale: string,
+): ScoredMatch {
+  return { guideline_id: guidelineId, score, rationale };
+}

apps/coder/src/services/behavioral/resolver.ts

@@ -0,0 +1,355 @@
+/**
+ * Relational resolver for behavioral guidelines.
+ *
+ * Port of boocontext-audit/src/resolver.ts — resolves DEPENDS_ON,
+ * PRIORITIZES, ENTAILS, TAG_ALL, TAG_PRIORITIZES relationships
+ * with an iterative convergence loop.
+ */
+
+// ─── Relationship types (self-contained) ───
+
+export enum RelationshipKind {
+  DEPENDS_ON = 'depends_on',
+  PRIORITIZES = 'prioritizes',
+  ENTAILS = 'entails',
+  TAG_ALL = 'tag_all',
+  TAG_PRIORITIZES = 'tag_prioritizes',
+}
+
+export enum RelationshipEntityKind {
+  GUIDELINE = 'guideline',
+  TAG = 'tag',
+}
+
+export interface RelationshipEntity {
+  id: string;
+  kind: RelationshipEntityKind;
+}
+
+export interface Relationship {
+  id: string;
+  creation_utc: string;
+  source: RelationshipEntity;
+  target: RelationshipEntity;
+  kind: RelationshipKind;
+  group_id?: string;
+}
+
+/**
+ * Minimal relationship store interface.
+ * The resolver only needs listRelationships. Implementations
+ * can back against files, postgres, or in-memory maps.
+ */
+export interface RelationshipStore {
+  listRelationships(
+    kind?: RelationshipKind,
+    sourceId?: string,
+    targetId?: string,
+  ): Promise<Relationship[]>;
+}
+
+// ─── Resolution types ───
+
+export type ResolvedEntityType = 'guideline' | 'journey' | 'tag';
+
+export interface ResolvedEntity {
+  entityType: ResolvedEntityType;
+  entityId: string;
+}
+
+export enum ResolutionKind {
+  NONE = 'none',
+  UNMET_DEPENDENCY = 'unmet_dependency',
+  DEPRIORITIZED = 'deprioritized',
+  ENTAILED = 'entailed',
+}
+
+export interface Resolution {
+  kind: ResolutionKind;
+  description: string;
+  relationshipId?: string;
+  counterparts?: ResolvedEntity[];
+}
+
+export interface GuidelineStub {
+  id: string;
+  priority: number;
+  tags: string[];
+}
+
+export interface GuidelineMatchStub {
+  guideline: GuidelineStub;
+}
+
+export interface ResolverResult {
+  matchedIds: Set<string>;
+  resolutions: Map<string, Resolution[]>;
+  converged: boolean;
+  iterations: number;
+}
+
+// ─── Constants ───
+
+export const MAX_ITERATIONS = 100;
+
+// ─── RelationalResolver ───
+
+export class RelationalResolver {
+  private store: RelationshipStore;
+
+  constructor(store: RelationshipStore) {
+    this.store = store;
+  }
+
+  async resolve(
+    matchedIds: Set<string>,
+    allGuidelines: GuidelineStub[],
+  ): Promise<ResolverResult> {
+    const resolutions = new Map<string, Resolution[]>();
+    const guidelinesById = new Map(allGuidelines.map((g) => [g.id, g]));
+    let currentIds = new Set(matchedIds);
+    const priorityRemoved = new Set<string>();
+    const entailedIds = new Set<string>();
+
+    let converged = false;
+    let iterations = 0;
+
+    for (iterations = 0; iterations < MAX_ITERATIONS; iterations++) {
+      const candidateIds = new Set(
+        [...currentIds].filter((id) => !priorityRemoved.has(id)),
+      );
+
+      const step1Ids = await this.applyDependencies(candidateIds, guidelinesById, resolutions);
+
+      const step2Ids = await this.applyPrioritization(
+        step1Ids,
+        guidelinesById,
+        resolutions,
+        priorityRemoved,
+      );
+
+      const step3Ids = this.applyNumericalPriority(
+        step2Ids,
+        guidelinesById,
+        resolutions,
+        priorityRemoved,
+        entailedIds,
+      );
+
+      const step4Ids = await this.applyEntailment(
+        step3Ids,
+        guidelinesById,
+        resolutions,
+        priorityRemoved,
+        entailedIds,
+      );
+
+      if (this.setsEqual(step4Ids, currentIds)) {
+        converged = true;
+        break;
+      }
+
+      currentIds = step4Ids;
+    }
+
+    for (const id of allGuidelines.map((g) => g.id)) {
+      if (!resolutions.has(id)) {
+        resolutions.set(id, [
+          { kind: ResolutionKind.NONE, description: 'No relational changes' },
+        ]);
+      }
+    }
+
+    return {
+      matchedIds: currentIds,
+      resolutions,
+      converged,
+      iterations: iterations + 1,
+    };
+  }
+
+  // ── Private steps ──
+
+  private async applyDependencies(
+    candidateIds: Set<string>,
+    _guidelinesById: Map<string, GuidelineStub>,
+    resolutions: Map<string, Resolution[]>,
+  ): Promise<Set<string>> {
+    const surviving = new Set(candidateIds);
+    const cache = new Map<string, Relationship[]>();
+
+    for (const gid of candidateIds) {
+      const rels = await this.getRelationshipsFromCache(cache, gid, RelationshipKind.DEPENDS_ON);
+
+      for (const rel of rels) {
+        const targetId = rel.target.id;
+        if (!candidateIds.has(targetId)) {
+          surviving.delete(gid);
+          this.addResolution(resolutions, gid, {
+            kind: ResolutionKind.UNMET_DEPENDENCY,
+            description: `Depends on ${targetId} which is not matched`,
+            relationshipId: rel.id,
+            counterparts: [{ entityType: 'guideline' as const, entityId: targetId }],
+          });
+          break;
+        }
+      }
+    }
+
+    return surviving;
+  }
+
+  private async applyPrioritization(
+    candidateIds: Set<string>,
+    guidelinesById: Map<string, GuidelineStub>,
+    resolutions: Map<string, Resolution[]>,
+    priorityRemoved: Set<string>,
+  ): Promise<Set<string>> {
+    const surviving = new Set(candidateIds);
+    const cache = new Map<string, Relationship[]>();
+
+    for (const gid of candidateIds) {
+      if (priorityRemoved.has(gid)) continue;
+
+      const allRels = await this.getAllRelationships(cache, gid);
+      const priorityRels = allRels.filter((r) => r.kind === RelationshipKind.PRIORITIZES);
+
+      for (const rel of priorityRels) {
+        const sourceId = rel.source.id;
+        if (sourceId !== gid) continue;
+        const targetId = rel.target.id;
+
+        if (candidateIds.has(targetId)) {
+          surviving.delete(targetId);
+          priorityRemoved.add(targetId);
+          this.addResolution(resolutions, targetId, {
+            kind: ResolutionKind.DEPRIORITIZED,
+            description: `Deprioritized by ${gid}`,
+            relationshipId: rel.id,
+            counterparts: [{ entityType: 'guideline' as const, entityId: gid }],
+          });
+        }
+      }
+    }
+
+    return surviving;
+  }
+
+  private applyNumericalPriority(
+    candidateIds: Set<string>,
+    guidelinesById: Map<string, GuidelineStub>,
+    resolutions: Map<string, Resolution[]>,
+    priorityRemoved: Set<string>,
+    entailedIds: Set<string>,
+  ): Set<string> {
+    if (candidateIds.size === 0) return candidateIds;
+
+    const nonEntailed = [...candidateIds].filter((id) => !entailedIds.has(id));
+    const entailed = [...candidateIds].filter((id) => entailedIds.has(id));
+
+    if (nonEntailed.length === 0) return new Set(entailed);
+
+    const priorities = nonEntailed.map((id) => guidelinesById.get(id)?.priority ?? 0);
+    const maxPriority = Math.max(...priorities);
+
+    const surviving = new Set<string>();
+
+    for (const id of nonEntailed) {
+      const priority = guidelinesById.get(id)?.priority ?? 0;
+      if (priority >= maxPriority) {
+        surviving.add(id);
+      } else {
+        priorityRemoved.add(id);
+        this.addResolution(resolutions, id, {
+          kind: ResolutionKind.DEPRIORITIZED,
+          description: `Lower priority (${priority} < ${maxPriority})`,
+        });
+      }
+    }
+
+    for (const id of entailed) {
+      surviving.add(id);
+    }
+
+    return surviving;
+  }
+
+  private async applyEntailment(
+    candidateIds: Set<string>,
+    guidelinesById: Map<string, GuidelineStub>,
+    resolutions: Map<string, Resolution[]>,
+    priorityRemoved: Set<string>,
+    entailedIds: Set<string>,
+  ): Promise<Set<string>> {
+    const result = new Set(candidateIds);
+    const cache = new Map<string, Relationship[]>();
+
+    for (const gid of candidateIds) {
+      if (priorityRemoved.has(gid)) continue;
+
+      const allRels = await this.getAllRelationships(cache, gid);
+      const entailRels = allRels.filter((r) => r.kind === RelationshipKind.ENTAILS);
+
+      for (const rel of entailRels) {
+        const targetId = rel.target.id;
+        if (!guidelinesById.has(targetId)) continue;
+        if (priorityRemoved.has(targetId)) continue;
+        if (entailedIds.has(targetId)) continue;
+
+        result.add(targetId);
+        entailedIds.add(targetId);
+        this.addResolution(resolutions, targetId, {
+          kind: ResolutionKind.ENTAILED,
+          description: `Entailed by ${gid}`,
+          relationshipId: rel.id,
+          counterparts: [{ entityType: 'guideline' as const, entityId: gid }],
+        });
+      }
+    }
+
+    return result;
+  }
+
+  // ── Cache helpers ──
+
+  private async getRelationshipsFromCache(
+    cache: Map<string, Relationship[]>,
+    gid: string,
+    kind: RelationshipKind,
+  ): Promise<Relationship[]> {
+    const key = `${kind}:${gid}`;
+    if (!cache.has(key)) {
+      cache.set(key, await this.store.listRelationships(kind, gid));
+    }
+    return cache.get(key)!;
+  }
+
+  private async getAllRelationships(
+    cache: Map<string, Relationship[]>,
+    gid: string,
+  ): Promise<Relationship[]> {
+    const result: Relationship[] = [];
+    const kinds = Object.values(RelationshipKind) as RelationshipKind[];
+    for (const kind of kinds) {
+      const rels = await this.getRelationshipsFromCache(cache, gid, kind);
+      const targetRels = await this.getRelationshipsFromCache(cache, `target:${gid}`, kind);
+      result.push(...rels, ...targetRels);
+    }
+    return result;
+  }
+
+  private addResolution(
+    resolutions: Map<string, Resolution[]>,
+    id: string,
+    resolution: Resolution,
+  ): void {
+    if (!resolutions.has(id)) resolutions.set(id, []);
+    resolutions.get(id)!.push(resolution);
+  }
+
+  private setsEqual(a: Set<string>, b: Set<string>): boolean {
+    if (a.size !== b.size) return false;
+    for (const item of a) if (!b.has(item)) return false;
+    return true;
+  }
+}

apps/coder/src/services/model-resolution/connected-providers-cache.ts

@@ -0,0 +1,34 @@
+import type { ModelMetadata } from "./provider-cache.js"
+
+export interface ProviderModelsCache {
+  readonly models: Record<string, readonly string[] | readonly ModelMetadata[]>
+  readonly connected: readonly string[]
+  readonly updatedAt: string
+}
+
+export interface ConnectedProvidersAdapter {
+  readConnectedProvidersCache(): string[] | null
+  findProviderModelMetadata(providerID: string, modelID: string): ModelMetadata | undefined
+  readProviderModelsCache(): ProviderModelsCache | null
+}
+
+export function readConnectedProvidersCache(): string[] | null {
+  return null
+}
+
+export function findProviderModelMetadata(
+  _providerID: string,
+  _modelID: string,
+): ModelMetadata | undefined {
+  return undefined
+}
+
+export function readProviderModelsCache(): ProviderModelsCache | null {
+  return null
+}
+
+export const connectedProvidersAdapter: ConnectedProvidersAdapter = {
+  readConnectedProvidersCache,
+  findProviderModelMetadata,
+  readProviderModelsCache,
+}

apps/coder/src/services/model-resolution/fallback-chain-from-models.ts

@@ -0,0 +1,128 @@
+import type { FallbackEntry } from "./model-requirement-types.js"
+import type { FallbackModelObject } from "./fallback-model-object.js"
+import { normalizeFallbackModels } from "./model-resolver.js"
+import { KNOWN_VARIANTS } from "./known-variants.js"
+
+function parseVariantFromModel(rawModel: string): { modelID: string; variant?: string } {
+  if (typeof rawModel !== "string") {
+    return { modelID: "" }
+  }
+  const trimmedModel = rawModel.trim()
+  if (!trimmedModel) {
+    return { modelID: "" }
+  }
+
+  const parenthesizedVariant = trimmedModel.match(/^(.*)\(([^()]+)\)\s*$/)
+  if (parenthesizedVariant) {
+    const modelID = parenthesizedVariant[1]?.trim() ?? ""
+    const variant = parenthesizedVariant[2]?.trim()
+    return variant ? { modelID, variant } : { modelID }
+  }
+
+  const spaceVariant = trimmedModel.match(/^(.*\S)\s+([a-z][a-z0-9_-]*)$/i)
+  if (spaceVariant) {
+    const modelID = spaceVariant[1]?.trim() ?? ""
+    const variant = spaceVariant[2]?.trim().toLowerCase()
+    if (variant && KNOWN_VARIANTS.has(variant)) {
+      return { modelID, variant }
+    }
+  }
+
+  return { modelID: trimmedModel }
+}
+
+export function parseFallbackModelEntry(
+  model: string,
+  contextProviderID: string | undefined,
+  defaultProviderID = "opencode",
+): FallbackEntry | undefined {
+  if (typeof model !== "string") return undefined
+  const trimmed = model.trim()
+  if (!trimmed) return undefined
+
+  const parts = trimmed.split("/")
+  const providerID =
+    parts.length >= 2 ? (parts[0]?.trim() ?? "") : (contextProviderID?.trim() || defaultProviderID)
+  const rawModelID = parts.length >= 2 ? parts.slice(1).join("/").trim() : trimmed
+  if (!providerID || !rawModelID) return undefined
+
+  const parsed = parseVariantFromModel(rawModelID)
+  if (!parsed.modelID) return undefined
+
+  return {
+    providers: [providerID],
+    model: parsed.modelID,
+    variant: parsed.variant,
+  }
+}
+
+export function parseFallbackModelObjectEntry(
+  obj: FallbackModelObject,
+  contextProviderID: string | undefined,
+  defaultProviderID = "opencode",
+): FallbackEntry | undefined {
+  const base = parseFallbackModelEntry(obj.model, contextProviderID, defaultProviderID)
+  if (!base) return undefined
+
+  return {
+    ...base,
+    variant: obj.variant ?? base.variant,
+    reasoningEffort: obj.reasoningEffort,
+    temperature: obj.temperature,
+    top_p: obj.top_p,
+    maxTokens: obj.maxTokens,
+    thinking: obj.thinking,
+  }
+}
+
+/**
+ * Find the most specific FallbackEntry whose `provider/model` is a prefix of
+ * the resolved `provider/modelID`.  Longest match wins so that e.g.
+ * `openai/gpt-5.4-preview` picks the entry for `openai/gpt-5.4-preview` over
+ * the shorter `openai/gpt-5.4`.
+ */
+export function findMostSpecificFallbackEntry(
+  providerID: string,
+  modelID: string,
+  chain: FallbackEntry[],
+): FallbackEntry | undefined {
+  const resolved = `${providerID}/${modelID}`.toLowerCase()
+
+  // Collect entries whose provider/model is a prefix of the resolved model,
+  // together with the length of the matching prefix (longest match wins).
+  const matches: { entry: FallbackEntry; matchLen: number }[] = []
+  for (const entry of chain) {
+    for (const p of entry.providers) {
+      const candidate = `${p}/${entry.model}`.toLowerCase()
+      if (resolved.startsWith(candidate)) {
+        matches.push({ entry, matchLen: candidate.length })
+        break // one match per entry is enough
+      }
+    }
+  }
+
+  if (matches.length === 0) return undefined
+  matches.sort((a, b) => b.matchLen - a.matchLen)
+  return matches[0]!.entry
+}
+
+export function buildFallbackChainFromModels(
+  fallbackModels: string | (string | FallbackModelObject)[] | undefined,
+  contextProviderID: string | undefined,
+  defaultProviderID = "opencode",
+): FallbackEntry[] | undefined {
+  const normalized = normalizeFallbackModels(fallbackModels)
+  if (!normalized || normalized.length === 0) return undefined
+
+  const parsed = normalized
+    .map((entry) => {
+      if (typeof entry === "string") {
+        return parseFallbackModelEntry(entry, contextProviderID, defaultProviderID)
+      }
+      return parseFallbackModelObjectEntry(entry, contextProviderID, defaultProviderID)
+    })
+    .filter((entry): entry is FallbackEntry => entry !== undefined)
+
+  if (parsed.length === 0) return undefined
+  return parsed
+}

apps/coder/src/services/model-resolution/fallback-model-object.ts

@@ -0,0 +1,9 @@
+export type FallbackModelObject = {
+  readonly model: string
+  readonly variant?: string
+  readonly reasoningEffort?: "none" | "minimal" | "low" | "medium" | "high" | "xhigh" | "max"
+  readonly temperature?: number
+  readonly top_p?: number
+  readonly maxTokens?: number
+  readonly thinking?: { readonly type: "enabled" | "disabled"; readonly budgetTokens?: number }
+}

apps/coder/src/services/model-resolution/index.ts

@@ -0,0 +1,80 @@
+export type {
+  FallbackEntry,
+  ModelRequirement,
+} from "./model-requirement-types.js"
+export type {
+  FallbackModelObject,
+} from "./fallback-model-object.js"
+export type {
+  DelegatedModelConfig,
+  ModelResolutionRequest,
+  ModelResolutionProvenance,
+  ModelResolutionResult,
+} from "./model-resolution-types.js"
+export type {
+  ModelResolutionInput,
+  ModelSource,
+  ExtendedModelResolutionInput,
+} from "./model-resolver.js"
+export {
+  resolveModel,
+  resolveModelWithFallback,
+  normalizeFallbackModels,
+  flattenToFallbackModelStrings,
+} from "./model-resolver.js"
+export {
+  normalizeModel,
+  normalizeModelID,
+} from "./model-normalization.js"
+export {
+  fuzzyMatchModel,
+  isModelAvailable,
+} from "./model-availability.js"
+export {
+  transformModelForProvider,
+  transformModelForProviderDisplay,
+} from "./provider-model-id-transform.js"
+export {
+  buildFallbackChainFromModels,
+  parseFallbackModelEntry,
+  parseFallbackModelObjectEntry,
+  findMostSpecificFallbackEntry,
+} from "./fallback-chain-from-models.js"
+export {
+  KNOWN_VARIANTS,
+} from "./known-variants.js"
+export {
+  _setModelResolutionLogImplementationForTesting,
+  resolveModelPipeline,
+} from "./model-resolution-pipeline.js"
+export type {
+  ModelResolutionRequest as PipelineModelResolutionRequest,
+  ModelResolutionProvenance as PipelineModelResolutionProvenance,
+  ModelResolutionResult as PipelineModelResolutionResult,
+  ModelResolutionDeps,
+} from "./model-resolution-pipeline.js"
+export {
+  isRetryableModelError,
+  shouldRetryError,
+  getNextFallback,
+  hasMoreFallbacks,
+  selectFallbackProvider,
+  selectFallbackProviderWithCache,
+} from "./model-error-classifier.js"
+export type {
+  ErrorInfo,
+} from "./model-error-classifier.js"
+export type {
+  ProviderCache,
+  ModelMetadata,
+} from "./provider-cache.js"
+export type {
+  ProviderModelsCache,
+  ConnectedProvidersAdapter,
+} from "./connected-providers-cache.js"
+export {
+  readConnectedProvidersCache,
+  findProviderModelMetadata,
+  readProviderModelsCache,
+  connectedProvidersAdapter,
+} from "./connected-providers-cache.js"

apps/coder/src/services/model-resolution/known-variants.ts

@@ -0,0 +1,16 @@
+/**
+ * Canonical set of recognised variant / effort tokens.
+ * Used by parseFallbackModelEntry (space-suffix detection) and
+ * flattenToFallbackModelStrings (inline-variant stripping).
+ */
+export const KNOWN_VARIANTS = new Set([
+  "low",
+  "medium",
+  "high",
+  "xhigh",
+  "max",
+  "minimal",
+  "none",
+  "auto",
+  "thinking",
+])

apps/coder/src/services/model-resolution/model-availability.ts

@@ -0,0 +1,64 @@
+function normalizeModelName(name: string): string {
+  return name
+    .toLowerCase()
+    .replace(/claude-(opus|sonnet|haiku)-(\d+)[.-](\d+)/g, "claude-$1-$2.$3")
+}
+
+export function fuzzyMatchModel(
+  target: string,
+  available: Set<string>,
+  providers?: string[],
+): string | null {
+  if (available.size === 0) {
+    return null
+  }
+
+  const targetNormalized = normalizeModelName(target)
+
+  let candidates = Array.from(available)
+  if (providers && providers.length > 0) {
+    const providerSet = new Set(providers)
+    candidates = candidates.filter((model) => {
+      const [provider] = model.split("/")
+      return providerSet.has(provider!)
+    })
+  }
+
+  if (candidates.length === 0) {
+    return null
+  }
+
+  const matches = candidates.filter((model) =>
+    normalizeModelName(model).includes(targetNormalized),
+  )
+
+  if (matches.length === 0) {
+    return null
+  }
+
+  const exactMatch = matches.find((model) => normalizeModelName(model) === targetNormalized)
+  if (exactMatch) {
+    return exactMatch
+  }
+
+  const exactModelIdMatches = matches.filter((model) => {
+    const modelId = model.split("/").slice(1).join("/")
+    return normalizeModelName(modelId) === targetNormalized
+  })
+  if (exactModelIdMatches.length > 0) {
+    return exactModelIdMatches.reduce((shortest, current) =>
+      current.length < shortest.length ? current : shortest,
+    )
+  }
+
+  return matches.reduce((shortest, current) =>
+    current.length < shortest.length ? current : shortest,
+  )
+}
+
+export function isModelAvailable(
+  targetModel: string,
+  availableModels: Set<string>,
+): boolean {
+  return fuzzyMatchModel(targetModel, availableModels) !== null
+}

apps/coder/src/services/model-resolution/model-error-classifier.ts

@@ -0,0 +1,261 @@
+import type { FallbackEntry } from "./model-requirement-types.js"
+import type { ProviderCache } from "./provider-cache.js"
+import * as connectedProvidersCache from "./connected-providers-cache.js"
+
+/**
+ * Error names that indicate a retryable model error.
+ * These errors halt execution and should trigger fallback retry.
+ */
+const RETRYABLE_ERROR_NAMES = new Set([
+  "providermodelnotfounderror",
+  "ratelimiterror",
+  "modelunavailableerror",
+  "providerconnectionerror",
+  "authenticationerror",
+])
+
+const STOP_ERROR_NAMES = new Set([
+  "quotaexceedederror",
+  "insufficientcreditserror",
+  "freeusagelimiterror",
+])
+
+/**
+ * Error names that should NOT trigger retry.
+ * These errors are typically user-induced or fixable without switching models.
+ */
+const NON_RETRYABLE_ERROR_NAMES = new Set([
+  "messageabortederror",
+  "permissiondeniederror",
+  "contextlengtherror",
+  "timeouterror",
+  "validationerror",
+  "syntaxerror",
+  "usererror",
+])
+
+/**
+ * Message patterns that indicate a retryable error even without a known error name.
+ */
+const RETRYABLE_MESSAGE_PATTERNS = [
+  "rate_limit",
+  "rate limit",
+  "usage_limit_reached",
+  "usage limit has been reached",
+  "quota",
+  "all credentials for model",
+  "cooling down",
+  "exhausted your capacity",
+  "not found",
+  "unavailable",
+  "insufficient",
+  "too many requests",
+  "over limit",
+  "overloaded",
+  "bad gateway",
+  "bad request",
+  "unknown provider",
+  "provider not found",
+  "model_not_supported",
+  "model not supported",
+  "model is not supported",
+  "connection error",
+  "network error",
+  "timeout",
+  "service unavailable",
+  "internal_server_error",
+  "free usage",
+  "usage exceeded",
+  "credit",
+  "balance",
+  "temporarily unavailable",
+  "try again",
+  "请稍后重试",
+  "503",
+  "502",
+  "504",
+  "429",
+  "529",
+  "selected provider is forbidden",
+  "provider is forbidden",
+  // Chinese retryable patterns (Zhipu, etc.)
+  "频率限制",           // "rate limit"
+  "请求过于频繁",       // "too many requests"
+  "暂时不可用",         // "temporarily unavailable"
+  "服务不可用",         // "service unavailable"
+  "server_error",
+  "an error occurred while processing",
+]
+
+/**
+ * Message patterns that indicate a non-retryable STOP error (quota/billing exhaustion).
+ * These take precedence over RETRYABLE_MESSAGE_PATTERNS.
+ */
+const STOP_MESSAGE_PATTERNS = [
+  "quota will reset after",
+  "quota exceeded",
+  "free usage limit",
+  "billing limit",
+  "billing hard limit",
+  "monthly limit",
+  "plan limit",
+  "subscription quota",
+  "subscription limit",
+  "payment required",
+  "out of credits",
+  "credits exhausted",
+  "insufficient credits",
+  "insufficient balance",
+  "credit balance",
+  "usage limit for this month",
+  "exhausted your capacity",
+  // GLM/Z.ai business error codes that indicate permanent quota/billing exhaustion
+  "daily call limit",
+  "daily limit",
+  "usage limit reached for",
+  "in arrears",
+  "fair use policy",
+  "recharge and try",
+  "使用上限",
+  "额度不足",
+  "余额不足",
+  "已耗尽",
+]
+
+const AUTO_RETRY_GATE_PATTERNS = [
+  "rate limit",
+  "cooling down",
+  "credentials for model",
+]
+
+function hasProviderAutoRetrySignal(message: string): boolean {
+  if (!message.includes("retrying in")) {
+    return false
+  }
+  return AUTO_RETRY_GATE_PATTERNS.some((pattern) => message.includes(pattern))
+}
+
+export interface ErrorInfo {
+  name?: string
+  message?: string
+  /** HTTP status code from the provider response (e.g., 429 for rate limit) */
+  statusCode?: number
+}
+
+/**
+ * Determines if an error is a retryable model error.
+ * Returns true if it's a known retryable type OR matches retryable message patterns.
+ */
+export function isRetryableModelError(error: ErrorInfo): boolean {
+  // If we have an error name, check against known lists
+  if (error.name) {
+    const errorNameLower = error.name.toLowerCase()
+    // Explicit non-retryable takes precedence
+    if (NON_RETRYABLE_ERROR_NAMES.has(errorNameLower)) {
+      return false
+    }
+    if (STOP_ERROR_NAMES.has(errorNameLower)) {
+      return false
+    }
+    // Check if it's a known retryable error
+    if (RETRYABLE_ERROR_NAMES.has(errorNameLower)) {
+      return true
+    }
+  }
+
+  // Check message patterns for unknown errors
+  const msg = error.message?.toLowerCase() ?? ""
+
+  // STOP patterns take precedence over retryable patterns
+  if (STOP_MESSAGE_PATTERNS.some((pattern) => msg.includes(pattern))) {
+    return false
+  }
+
+  if (hasProviderAutoRetrySignal(msg)) {
+    return true
+  }
+
+  // HTTP status code check: catches rate-limit errors regardless of message format/language.
+  // Uses the same codes as runtime-fallback config (400 excluded as it is a permanent client error).
+  if (
+    error.statusCode != null &&
+    (error.statusCode === 429 || error.statusCode === 503 || error.statusCode === 529)
+  ) {
+    return true
+  }
+
+  return RETRYABLE_MESSAGE_PATTERNS.some((pattern) => msg.includes(pattern))
+}
+
+/**
+ * Determines if an error should trigger a fallback retry.
+ * Returns true for errors that halt execution.
+ */
+export function shouldRetryError(error: ErrorInfo): boolean {
+  return isRetryableModelError(error)
+}
+
+/**
+ * Gets the next fallback model from the chain based on attempt count.
+ * Returns undefined if all fallbacks have been exhausted.
+ */
+export function getNextFallback(
+  fallbackChain: FallbackEntry[],
+  attemptCount: number,
+): FallbackEntry | undefined {
+  return fallbackChain[attemptCount]
+}
+
+/**
+ * Checks if there are more fallbacks available after the current attempt.
+ */
+export function hasMoreFallbacks(
+  fallbackChain: FallbackEntry[],
+  attemptCount: number,
+): boolean {
+  return attemptCount < fallbackChain.length
+}
+
+/**
+ * Selects the best provider for a fallback entry.
+ * Priority:
+ * 1) First connected provider in the entry's provider preference order
+ * 2) Preferred provider when connected (and entry providers are unavailable)
+ * 3) First provider listed in the fallback entry
+ */
+export function selectFallbackProvider(
+  providers: string[],
+  preferredProviderID?: string,
+): string {
+  return selectFallbackProviderWithCache(
+    providers,
+    connectedProvidersCache,
+    preferredProviderID,
+  )
+}
+
+export function selectFallbackProviderWithCache(
+  providers: string[],
+  providerCache: ProviderCache,
+  preferredProviderID?: string,
+): string {
+  const connectedProviders = providerCache.readConnectedProvidersCache()
+  if (connectedProviders) {
+    const connectedSet = new Set(connectedProviders.map(p => p.toLowerCase()))
+
+    for (const provider of providers) {
+      if (connectedSet.has(provider.toLowerCase())) {
+        return provider
+      }
+    }
+
+    if (
+      preferredProviderID &&
+      connectedSet.has(preferredProviderID.toLowerCase())
+    ) {
+      return preferredProviderID
+    }
+  }
+
+  return providers[0] ?? preferredProviderID ?? "opencode"
+}

apps/coder/src/services/model-resolution/model-normalization.ts

@@ -0,0 +1,8 @@
+export function normalizeModel(model?: string): string | undefined {
+  const trimmed = model?.trim()
+  return trimmed || undefined
+}
+
+export function normalizeModelID(modelID: string): string {
+  return modelID.replace(/\.(\d+)/g, "-$1")
+}

apps/coder/src/services/model-resolution/model-requirement-types.ts

@@ -0,0 +1,18 @@
+export type FallbackEntry = {
+  providers: string[];
+  model: string;
+  variant?: string; // Entry-specific variant (e.g., GPT->high, Opus->max)
+  reasoningEffort?: string;
+  temperature?: number;
+  top_p?: number;
+  maxTokens?: number;
+  thinking?: { type: "enabled" | "disabled"; budgetTokens?: number };
+};
+
+export type ModelRequirement = {
+  fallbackChain: FallbackEntry[];
+  variant?: string; // Default variant (used when entry doesn't specify one)
+  requiresModel?: string; // If set, only activates when this model is available (fuzzy match)
+  requiresAnyModel?: boolean; // If true, requires at least ONE model in fallbackChain to be available (or empty availability treated as unavailable)
+  requiresProvider?: string[]; // If set, only activates when any of these providers is connected
+};

apps/coder/src/services/model-resolution/model-resolution-pipeline.ts

@@ -0,0 +1,256 @@
+import { fuzzyMatchModel } from "./model-availability.js"
+import type { FallbackEntry } from "./model-requirement-types.js"
+import { transformModelForProvider } from "./provider-model-id-transform.js"
+import { normalizeModel } from "./model-normalization.js"
+import type { ProviderCache } from "./provider-cache.js"
+
+type LogImplementation = (message: string, data?: unknown) => void
+
+let logImplementationForTesting: LogImplementation | undefined
+
+function log(message: string, data?: unknown): void {
+  const logImpl = logImplementationForTesting
+  if (!logImpl) {
+    return
+  }
+  if (arguments.length === 1) {
+    logImpl(message)
+    return
+  }
+  logImpl(message, data)
+}
+
+export function _setModelResolutionLogImplementationForTesting(
+  logImplementation: LogImplementation | undefined,
+): void {
+  logImplementationForTesting = logImplementation
+}
+
+export type ModelResolutionRequest = {
+  intent?: {
+    uiSelectedModel?: string
+    userModel?: string
+    userFallbackModels?: string[]
+    categoryDefaultModel?: string
+  }
+  constraints: {
+    availableModels: Set<string>
+    connectedProviders?: string[] | null
+  }
+  policy?: {
+    fallbackChain?: FallbackEntry[]
+    systemDefaultModel?: string
+  }
+}
+
+export type ModelResolutionProvenance =
+  | "override"
+  | "category-default"
+  | "provider-fallback"
+  | "system-default"
+
+export type ModelResolutionResult = {
+  model: string
+  provenance: ModelResolutionProvenance
+  variant?: string
+  attempted?: string[]
+  reason?: string
+}
+
+export type ModelResolutionDeps = {
+  fuzzyMatchModel: (
+    target: string,
+    available: Set<string>,
+    providers?: string[],
+  ) => string | null
+  transformModelForProvider: (provider: string, model: string) => string
+}
+
+const DEFAULT_MODEL_RESOLUTION_DEPS: ModelResolutionDeps = {
+  fuzzyMatchModel,
+  transformModelForProvider,
+}
+
+
+export function resolveModelPipeline(
+  request: ModelResolutionRequest,
+  providerCache: ProviderCache = {
+    readConnectedProvidersCache: () => null,
+    findProviderModelMetadata: () => undefined,
+  },
+  deps: ModelResolutionDeps = DEFAULT_MODEL_RESOLUTION_DEPS,
+): ModelResolutionResult | undefined {
+  const attempted: string[] = []
+  const { intent, constraints, policy } = request
+  const availableModels = constraints.availableModels
+  const fallbackChain = policy?.fallbackChain
+  const systemDefaultModel = policy?.systemDefaultModel
+
+  const normalizedUiModel = normalizeModel(intent?.uiSelectedModel)
+  if (normalizedUiModel) {
+    log("Model resolved via UI selection", { model: normalizedUiModel })
+    return { model: normalizedUiModel, provenance: "override" }
+  }
+
+  const normalizedUserModel = normalizeModel(intent?.userModel)
+  if (normalizedUserModel) {
+    log("Model resolved via config override", { model: normalizedUserModel })
+    return { model: normalizedUserModel, provenance: "override" }
+  }
+
+  const normalizedCategoryDefault = normalizeModel(intent?.categoryDefaultModel)
+  if (normalizedCategoryDefault) {
+    attempted.push(normalizedCategoryDefault)
+    if (availableModels.size > 0) {
+      const parts = normalizedCategoryDefault.split("/")
+      const providerHint = parts.length >= 2 ? [parts[0]!] : undefined
+      const match = deps.fuzzyMatchModel(normalizedCategoryDefault, availableModels, providerHint)
+      if (match) {
+        log("Model resolved via category default (fuzzy matched)", {
+          original: normalizedCategoryDefault,
+          matched: match,
+        })
+        return { model: match, provenance: "category-default", attempted }
+      }
+    } else {
+      const connectedProviders = constraints.connectedProviders ?? providerCache.readConnectedProvidersCache()
+      if (connectedProviders === null) {
+        log("Model resolved via category default (no cache, first run)", {
+          model: normalizedCategoryDefault,
+        })
+        return { model: normalizedCategoryDefault, provenance: "category-default", attempted }
+      }
+      const parts = normalizedCategoryDefault.split("/")
+      if (parts.length >= 2) {
+        const provider = parts[0]!
+        if (connectedProviders.includes(provider)) {
+          const modelName = parts.slice(1).join("/")
+          const transformedModel = `${provider}/${deps.transformModelForProvider(provider, modelName)}`
+          log("Model resolved via category default (connected provider)", {
+            model: transformedModel,
+            original: normalizedCategoryDefault,
+          })
+          return { model: transformedModel, provenance: "category-default", attempted }
+        }
+      }
+    }
+    log("Category default model not available, falling through to fallback chain", {
+      model: normalizedCategoryDefault,
+    })
+  }
+
+  //#when - user configured fallback_models, try them before hardcoded fallback chain
+  const userFallbackModels = intent?.userFallbackModels
+  if (userFallbackModels && userFallbackModels.length > 0) {
+    if (availableModels.size === 0) {
+      const connectedProviders = constraints.connectedProviders ?? providerCache.readConnectedProvidersCache()
+      const connectedSet = connectedProviders ? new Set(connectedProviders) : null
+
+      if (connectedSet !== null) {
+        for (const model of userFallbackModels) {
+          attempted.push(model)
+          const parts = model.split("/")
+          if (parts.length >= 2) {
+            const provider = parts[0]!
+            if (connectedSet.has(provider)) {
+              const modelName = parts.slice(1).join("/")
+              const transformedModel = `${provider}/${deps.transformModelForProvider(provider, modelName)}`
+              log("Model resolved via user fallback_models (connected provider)", { model: transformedModel, original: model })
+              return { model: transformedModel, provenance: "provider-fallback", attempted }
+            }
+          }
+        }
+        log("No connected provider found in user fallback_models, falling through to hardcoded chain")
+      }
+    } else {
+      for (const model of userFallbackModels) {
+        attempted.push(model)
+        const parts = model.split("/")
+        const providerHint = parts.length >= 2 ? [parts[0]!] : undefined
+        const match = deps.fuzzyMatchModel(model, availableModels, providerHint)
+        if (match) {
+          log("Model resolved via user fallback_models (availability confirmed)", { model, match })
+          return { model: match, provenance: "provider-fallback", attempted }
+        }
+      }
+      log("No available model found in user fallback_models, falling through to hardcoded chain")
+    }
+  }
+
+  if (fallbackChain && fallbackChain.length > 0) {
+    if (availableModels.size === 0) {
+      const connectedProviders = constraints.connectedProviders ?? providerCache.readConnectedProvidersCache()
+      const connectedSet = connectedProviders ? new Set(connectedProviders) : null
+
+      if (connectedSet === null) {
+        log("Model fallback chain skipped (no connected providers cache) - falling through to system default")
+      } else {
+        for (const entry of fallbackChain) {
+          for (const provider of entry.providers) {
+            if (connectedSet.has(provider)) {
+              const transformedModelId = deps.transformModelForProvider(provider, entry.model)
+              const model = `${provider}/${transformedModelId}`
+              log("Model resolved via fallback chain (connected provider)", {
+                provider,
+                model: transformedModelId,
+                variant: entry.variant,
+              })
+              return {
+                model,
+                provenance: "provider-fallback",
+                variant: entry.variant,
+                attempted,
+              }
+            }
+          }
+        }
+        log("No connected provider found in fallback chain, falling through to system default")
+      }
+    } else {
+      for (const entry of fallbackChain) {
+        for (const provider of entry.providers) {
+          const fullModel = `${provider}/${entry.model}`
+          const match = deps.fuzzyMatchModel(fullModel, availableModels, [provider])
+          if (match) {
+            log("Model resolved via fallback chain (availability confirmed)", {
+              provider,
+              model: entry.model,
+              match,
+              variant: entry.variant,
+            })
+            return {
+              model: match,
+              provenance: "provider-fallback",
+              variant: entry.variant,
+              attempted,
+            }
+          }
+        }
+
+        const crossProviderMatch = deps.fuzzyMatchModel(entry.model, availableModels)
+        if (crossProviderMatch) {
+          log("Model resolved via fallback chain (cross-provider fuzzy match)", {
+            model: entry.model,
+            match: crossProviderMatch,
+            variant: entry.variant,
+          })
+          return {
+            model: crossProviderMatch,
+            provenance: "provider-fallback",
+            variant: entry.variant,
+            attempted,
+          }
+        }
+      }
+      log("No available model found in fallback chain, falling through to system default")
+    }
+  }
+
+  if (systemDefaultModel === undefined) {
+    log("No model resolved - systemDefaultModel not configured")
+    return undefined
+  }
+
+  log("Model resolved via system default", { model: systemDefaultModel })
+  return { model: systemDefaultModel, provenance: "system-default", attempted }
+}

apps/coder/src/services/model-resolution/model-resolution-types.ts

@@ -0,0 +1,41 @@
+import type { FallbackEntry } from "./model-requirement-types.js"
+
+export interface DelegatedModelConfig {
+  providerID: string
+  modelID: string
+  variant?: string
+  reasoningEffort?: string
+  temperature?: number
+  top_p?: number
+  maxTokens?: number
+  thinking?: { type: "enabled" | "disabled"; budgetTokens?: number }
+}
+
+export type ModelResolutionRequest = {
+  intent?: {
+    uiSelectedModel?: string
+    userModel?: string
+    categoryDefaultModel?: string
+  }
+  constraints: {
+    availableModels: Set<string>
+  }
+  policy?: {
+    fallbackChain?: FallbackEntry[]
+    systemDefaultModel?: string
+  }
+}
+
+export type ModelResolutionProvenance =
+  | "override"
+  | "category-default"
+  | "provider-fallback"
+  | "system-default"
+
+export type ModelResolutionResult = {
+  model: string
+  provenance: ModelResolutionProvenance
+  variant?: string
+  attempted?: string[]
+  reason?: string
+}

apps/coder/src/services/model-resolution/model-resolver.ts

@@ -0,0 +1,109 @@
+import type { FallbackEntry } from "./model-requirement-types.js"
+import type { FallbackModelObject } from "./fallback-model-object.js"
+import { normalizeModel } from "./model-normalization.js"
+import { resolveModelPipeline } from "./model-resolution-pipeline.js"
+import { KNOWN_VARIANTS } from "./known-variants.js"
+import type { ConnectedProvidersAdapter } from "./connected-providers-cache.js"
+import * as connectedProvidersCache from "./connected-providers-cache.js"
+
+export type ModelResolutionInput = {
+  userModel?: string
+  inheritedModel?: string
+  systemDefault?: string
+}
+
+export type ModelSource =
+  | "override"
+  | "category-default"
+  | "provider-fallback"
+  | "system-default"
+
+export type ModelResolutionResult = {
+  model: string
+  source: ModelSource
+  variant?: string
+}
+
+export type ExtendedModelResolutionInput = {
+  uiSelectedModel?: string
+  userModel?: string
+  userFallbackModels?: string[]
+  categoryDefaultModel?: string
+  fallbackChain?: FallbackEntry[]
+  availableModels: Set<string>
+  systemDefaultModel?: string
+}
+
+
+export function resolveModel(input: ModelResolutionInput): string | undefined {
+  return (
+    normalizeModel(input.userModel) ??
+    normalizeModel(input.inheritedModel) ??
+    input.systemDefault
+  )
+}
+
+export function resolveModelWithFallback(
+  input: ExtendedModelResolutionInput,
+  connectedProvidersAdapter: ConnectedProvidersAdapter = connectedProvidersCache,
+): ModelResolutionResult | undefined {
+  const { uiSelectedModel, userModel, userFallbackModels, categoryDefaultModel, fallbackChain, availableModels, systemDefaultModel } = input
+  const resolved = resolveModelPipeline({
+    intent: { uiSelectedModel, userModel, userFallbackModels, categoryDefaultModel },
+    constraints: { availableModels },
+    policy: { fallbackChain, systemDefaultModel },
+  }, connectedProvidersAdapter)
+
+  if (!resolved) {
+    return undefined
+  }
+
+  return {
+    model: resolved.model,
+    source: resolved.provenance,
+    variant: resolved.variant,
+  }
+}
+
+/**
+ * Normalizes fallback_models config to a mixed array.
+ * Accepts string, string[], or mixed arrays of strings and FallbackModelObject entries.
+ */
+export function normalizeFallbackModels(
+  models: string | (string | FallbackModelObject)[] | undefined,
+): (string | FallbackModelObject)[] | undefined {
+  if (!models) return undefined
+  if (typeof models === "string") return [models]
+  return models
+}
+
+/**
+ * Extracts plain model strings from a mixed fallback models array.
+ * Object entries are flattened to "model" or "model(variant)" strings.
+ * Use this when consumers need string[] (e.g., resolveModelForDelegateTask).
+ */
+export function flattenToFallbackModelStrings(
+  models: (string | FallbackModelObject)[] | undefined,
+): string[] | undefined {
+  if (!models) return undefined
+  return models.map((entry) => {
+    if (typeof entry === "string") return entry
+    const variant = entry.variant
+    if (variant) {
+      // Strip any supported inline variant syntax before appending explicit override.
+      // Supports both parenthesized and space-suffix forms so we don't emit
+      // invalid strings like "provider/model high(low)".
+      const model = entry.model
+        .replace(/\([^()]+\)\s*$/, "")
+        .replace(/\s+([a-z][a-z0-9_-]*)\s*$/i, (_match: string, suffix: string) => {
+          const normalized = String(suffix).toLowerCase()
+          return KNOWN_VARIANTS.has(normalized)
+            ? ""
+            : _match
+        })
+        .trim()
+      return `${model}(${variant})`
+    }
+    return entry.model
+  })
+}

apps/coder/src/services/model-resolution/provider-cache.ts

@@ -0,0 +1,27 @@
+export interface ModelMetadata {
+  readonly id: string
+  readonly provider?: string
+  readonly context?: number
+  readonly output?: number
+  readonly name?: string
+  readonly variants?: Record<string, unknown>
+  readonly limit?: {
+    readonly context?: number
+    readonly input?: number
+    readonly output?: number
+  }
+  readonly modalities?: {
+    readonly input?: string[]
+    readonly output?: string[]
+  }
+  readonly capabilities?: Record<string, unknown>
+  readonly reasoning?: boolean
+  readonly temperature?: boolean
+  readonly tool_call?: boolean
+  readonly [key: string]: unknown
+}
+
+export interface ProviderCache {
+  readConnectedProvidersCache(): string[] | null
+  findProviderModelMetadata(providerID: string, modelID: string): ModelMetadata | undefined
+}

apps/coder/src/services/model-resolution/provider-model-id-transform.ts

@@ -0,0 +1,69 @@
+function inferSubProvider(model: string): string | undefined {
+  if (model.startsWith("claude-")) return "anthropic"
+  if (model.startsWith("gpt-")) return "openai"
+  if (model.startsWith("gemini-")) return "google"
+  if (model.startsWith("grok-")) return "xai"
+  if (model.startsWith("minimax-")) return "minimax"
+  if (model.startsWith("kimi-")) return "moonshotai"
+  if (model.startsWith("glm-")) return "zai"
+  return undefined
+}
+
+const CLAUDE_VERSION_DOT = /claude-(\w+)-(\d+)-(\d+)/g
+const GEMINI_31_PRO_PREVIEW = /gemini-3\.1-pro(?!-)/g
+const GEMINI_3_FLASH_PREVIEW = /gemini-3-flash(?!-)/g
+
+function claudeVersionDot(model: string): string {
+  return model.replace(CLAUDE_VERSION_DOT, "claude-$1-$2.$3")
+}
+
+function applyGatewayTransforms(model: string): string {
+  return claudeVersionDot(model).replace(
+    GEMINI_31_PRO_PREVIEW,
+    "gemini-3.1-pro-preview",
+  )
+}
+
+function transformModelForProviderUsingAnthropicBehavior(
+  provider: string,
+  model: string,
+): string {
+  if (provider === "vercel") {
+    const slashIndex = model.indexOf("/")
+    if (slashIndex !== -1) {
+      const subProvider = model.substring(0, slashIndex)
+      const subModel = model.substring(slashIndex + 1)
+      return `${subProvider}/${applyGatewayTransforms(subModel)}`
+    }
+    const subProvider = inferSubProvider(model)
+    if (subProvider) {
+      return `${subProvider}/${applyGatewayTransforms(model)}`
+    }
+    return model
+  }
+  if (provider === "github-copilot") {
+    return claudeVersionDot(model)
+      .replace(GEMINI_31_PRO_PREVIEW, "gemini-3.1-pro-preview")
+      .replace(GEMINI_3_FLASH_PREVIEW, "gemini-3-flash-preview")
+  }
+  if (provider === "google") {
+    return model
+      .replace(GEMINI_31_PRO_PREVIEW, "gemini-3.1-pro-preview")
+      .replace(GEMINI_3_FLASH_PREVIEW, "gemini-3-flash-preview")
+  }
+  if (provider === "anthropic") {
+    return model
+  }
+  return model
+}
+
+export function transformModelForProvider(provider: string, model: string): string {
+  return transformModelForProviderUsingAnthropicBehavior(provider, model)
+}
+
+export function transformModelForProviderDisplay(
+  provider: string,
+  model: string,
+): string {
+  return transformModelForProviderUsingAnthropicBehavior(provider, model)
+}