Config: support per-agent model fallbacks

src/auto-reply/reply/agent-runner.ts

@@ -2,6 +2,7 @@ import crypto from "node:crypto";
 import fs from "node:fs";
 import { runCliAgent } from "../../agents/cli-runner.js";
 import { getCliSessionId, setCliSessionId } from "../../agents/cli-session.js";
+import { resolveAgentModelFallbacksOverride } from "../../agents/agent-scope.js";
 import { lookupContextTokens } from "../../agents/context.js";
 import { DEFAULT_CONTEXT_TOKENS } from "../../agents/defaults.js";
 import { resolveModelAuthMode } from "../../agents/model-auth.js";
@@ -394,6 +395,10 @@ export async function runReplyAgent(params: {
         cfg: followupRun.run.config,
         provider: followupRun.run.provider,
         model: followupRun.run.model,
+        fallbacksOverride: resolveAgentModelFallbacksOverride(
+          followupRun.run.config,
+          resolveAgentIdFromSessionKey(followupRun.run.sessionKey),
+        ),
         run: (provider, model) =>
           runEmbeddedPiAgent({
             sessionId: followupRun.run.sessionId,
@@ -586,6 +591,10 @@ export async function runReplyAgent(params: {
           cfg: followupRun.run.config,
           provider: followupRun.run.provider,
           model: followupRun.run.model,
+          fallbacksOverride: resolveAgentModelFallbacksOverride(
+            followupRun.run.config,
+            resolveAgentIdFromSessionKey(followupRun.run.sessionKey),
+          ),
           run: (provider, model) => {
             if (isCliProvider(provider, followupRun.run.config)) {
               const startedAt = Date.now();

src/auto-reply/reply/directive-handling.ts

@@ -1,8 +1,10 @@
+import { resolveClawdbotAgentDir } from "../../agents/agent-paths.js";
 import {
   resolveAgentConfig,
   resolveAgentDir,
   resolveDefaultAgentId,
   resolveSessionAgentId,
+  resolveAgentModelPrimary,
 } from "../../agents/agent-scope.js";
 import {
   isProfileInCooldown,
@@ -1593,7 +1595,7 @@ export function resolveDefaultModel(params: {
   aliasIndex: ModelAliasIndex;
 } {
   const agentModelOverride = params.agentId
-    ? resolveAgentConfig(params.cfg, params.agentId)?.model?.trim()
+    ? resolveAgentModelPrimary(params.cfg, params.agentId)
     : undefined;
   const cfg =
     agentModelOverride && agentModelOverride.length > 0

src/auto-reply/reply/followup-runner.ts

@@ -1,10 +1,12 @@
 import crypto from "node:crypto";
+import { resolveAgentModelFallbacksOverride } from "../../agents/agent-scope.js";
 import { lookupContextTokens } from "../../agents/context.js";
 import { DEFAULT_CONTEXT_TOKENS } from "../../agents/defaults.js";
 import { runWithModelFallback } from "../../agents/model-fallback.js";
 import { runEmbeddedPiAgent } from "../../agents/pi-embedded.js";
 import { hasNonzeroUsage } from "../../agents/usage.js";
 import {
+  resolveAgentIdFromSessionKey,
   type SessionEntry,
   updateSessionStoreEntry,
 } from "../../config/sessions.js";
@@ -136,6 +138,10 @@ export function createFollowupRunner(params: {
           cfg: queued.run.config,
           provider: queued.run.provider,
           model: queued.run.model,
+          fallbacksOverride: resolveAgentModelFallbacksOverride(
+            queued.run.config,
+            resolveAgentIdFromSessionKey(queued.run.sessionKey),
+          ),
           run: (provider, model) =>
             runEmbeddedPiAgent({
               sessionId: queued.run.sessionId,