refactor: centralize model override validation

docs/concepts/model-failover.md

@@ -83,7 +83,10 @@ State is stored in `auth-profiles.json` under `usageStats`:
 
 If all profiles for a provider fail, Clawdbot moves to the next model in
 `agents.defaults.model.fallbacks`. This applies to auth failures, rate limits, and
-timeouts that exhausted profile rotation.
+timeouts that exhausted profile rotation (other errors do not advance fallback).
+
+When a run starts with a model override (hooks or CLI), fallbacks still end at
+`agents.defaults.model.primary` after trying any configured fallbacks.
 
 ## Related config
 

src/agents/model-selection.test.ts

@@ -6,6 +6,7 @@ import {
   buildAllowedModelSet,
   modelKey,
   parseModelRef,
+  resolveAllowedModelRef,
   resolveHooksGmailModel,
 } from "./model-selection.js";
 
@@ -143,3 +144,62 @@ describe("resolveHooksGmailModel", () => {
     });
   });
 });
+
+describe("resolveAllowedModelRef", () => {
+  it("resolves aliases when allowed", () => {
+    const cfg = {
+      agents: {
+        defaults: {
+          models: {
+            "anthropic/claude-sonnet-4-1": { alias: "Sonnet" },
+          },
+        },
+      },
+    } satisfies ClawdbotConfig;
+    const resolved = resolveAllowedModelRef({
+      cfg,
+      catalog: [
+        {
+          provider: "anthropic",
+          id: "claude-sonnet-4-1",
+          name: "Sonnet",
+        },
+      ],
+      raw: "Sonnet",
+      defaultProvider: "anthropic",
+      defaultModel: "claude-opus-4-5",
+    });
+    expect("error" in resolved).toBe(false);
+    if ("ref" in resolved) {
+      expect(resolved.ref).toEqual({
+        provider: "anthropic",
+        model: "claude-sonnet-4-1",
+      });
+    }
+  });
+
+  it("rejects disallowed models", () => {
+    const cfg = {
+      agents: {
+        defaults: {
+          models: {
+            "openai/gpt-4": { alias: "GPT4" },
+          },
+        },
+      },
+    } satisfies ClawdbotConfig;
+    const resolved = resolveAllowedModelRef({
+      cfg,
+      catalog: [
+        { provider: "openai", id: "gpt-4", name: "GPT-4" },
+        { provider: "anthropic", id: "claude-sonnet-4-1", name: "Sonnet" },
+      ],
+      raw: "anthropic/claude-sonnet-4-1",
+      defaultProvider: "openai",
+      defaultModel: "gpt-4",
+    });
+    expect(resolved).toEqual({
+      error: "model not allowed: anthropic/claude-sonnet-4-1",
+    });
+  });
+});

src/agents/model-selection.ts

@@ -197,6 +197,76 @@ export function buildAllowedModelSet(params: {
   return { allowAny: false, allowedCatalog, allowedKeys };
 }
 
+export type ModelRefStatus = {
+  key: string;
+  inCatalog: boolean;
+  allowAny: boolean;
+  allowed: boolean;
+};
+
+export function getModelRefStatus(params: {
+  cfg: ClawdbotConfig;
+  catalog: ModelCatalogEntry[];
+  ref: ModelRef;
+  defaultProvider: string;
+  defaultModel?: string;
+}): ModelRefStatus {
+  const allowed = buildAllowedModelSet({
+    cfg: params.cfg,
+    catalog: params.catalog,
+    defaultProvider: params.defaultProvider,
+    defaultModel: params.defaultModel,
+  });
+  const key = modelKey(params.ref.provider, params.ref.model);
+  return {
+    key,
+    inCatalog: params.catalog.some(
+      (entry) => modelKey(entry.provider, entry.id) === key,
+    ),
+    allowAny: allowed.allowAny,
+    allowed: allowed.allowAny || allowed.allowedKeys.has(key),
+  };
+}
+
+export function resolveAllowedModelRef(params: {
+  cfg: ClawdbotConfig;
+  catalog: ModelCatalogEntry[];
+  raw: string;
+  defaultProvider: string;
+  defaultModel?: string;
+}):
+  | { ref: ModelRef; key: string }
+  | {
+      error: string;
+    } {
+  const trimmed = params.raw.trim();
+  if (!trimmed) return { error: "invalid model: empty" };
+
+  const aliasIndex = buildModelAliasIndex({
+    cfg: params.cfg,
+    defaultProvider: params.defaultProvider,
+  });
+  const resolved = resolveModelRefFromString({
+    raw: trimmed,
+    defaultProvider: params.defaultProvider,
+    aliasIndex,
+  });
+  if (!resolved) return { error: `invalid model: ${trimmed}` };
+
+  const status = getModelRefStatus({
+    cfg: params.cfg,
+    catalog: params.catalog,
+    ref: resolved.ref,
+    defaultProvider: params.defaultProvider,
+    defaultModel: params.defaultModel,
+  });
+  if (!status.allowed) {
+    return { error: `model not allowed: ${status.key}` };
+  }
+
+  return { ref: resolved.ref, key: status.key };
+}
+
 export function resolveThinkingDefault(params: {
   cfg: ClawdbotConfig;
   provider: string;

src/commands/doctor.ts

@@ -8,6 +8,13 @@ import {
   resolveAgentWorkspaceDir,
   resolveDefaultAgentId,
 } from "../agents/agent-scope.js";
+import { DEFAULT_MODEL, DEFAULT_PROVIDER } from "../agents/defaults.js";
+import { loadModelCatalog } from "../agents/model-catalog.js";
+import {
+  getModelRefStatus,
+  resolveConfiguredModelRef,
+  resolveHooksGmailModel,
+} from "../agents/model-selection.js";
 import { buildWorkspaceSkillStatus } from "../agents/skills-status.js";
 import type { ClawdbotConfig } from "../config/config.js";
 import {
@@ -201,6 +208,48 @@ export async function doctorCommand(
 
   await noteSecurityWarnings(cfg);
 
+  if (cfg.hooks?.gmail?.model?.trim()) {
+    const hooksModelRef = resolveHooksGmailModel({
+      cfg,
+      defaultProvider: DEFAULT_PROVIDER,
+    });
+    if (!hooksModelRef) {
+      note(
+        `- hooks.gmail.model "${cfg.hooks.gmail.model}" could not be resolved`,
+        "Hooks",
+      );
+    } else {
+      const { provider: defaultProvider, model: defaultModel } =
+        resolveConfiguredModelRef({
+          cfg,
+          defaultProvider: DEFAULT_PROVIDER,
+          defaultModel: DEFAULT_MODEL,
+        });
+      const catalog = await loadModelCatalog({ config: cfg });
+      const status = getModelRefStatus({
+        cfg,
+        catalog,
+        ref: hooksModelRef,
+        defaultProvider,
+        defaultModel,
+      });
+      const warnings: string[] = [];
+      if (!status.allowed) {
+        warnings.push(
+          `- hooks.gmail.model "${status.key}" not in agents.defaults.models allowlist (will use primary instead)`,
+        );
+      }
+      if (!status.inCatalog) {
+        warnings.push(
+          `- hooks.gmail.model "${status.key}" not in the model catalog (may fail at runtime)`,
+        );
+      }
+      if (warnings.length > 0) {
+        note(warnings.join("\n"), "Hooks");
+      }
+    }
+  }
+
   if (
     options.nonInteractive !== true &&
     process.platform === "linux" &&

src/cron/isolated-agent.ts

@@ -9,12 +9,10 @@ import {
 import { loadModelCatalog } from "../agents/model-catalog.js";
 import { runWithModelFallback } from "../agents/model-fallback.js";
 import {
-  buildAllowedModelSet,
-  buildModelAliasIndex,
-  modelKey,
+  getModelRefStatus,
+  resolveAllowedModelRef,
   resolveConfiguredModelRef,
   resolveHooksGmailModel,
-  resolveModelRefFromString,
   resolveThinkingDefault,
 } from "../agents/model-selection.js";
 import { runEmbeddedPiAgent } from "../agents/pi-embedded.js";
@@ -301,14 +299,14 @@ export async function runCronIsolatedAgentTurn(params: {
       })
     : null;
   if (hooksGmailModelRef) {
-    const allowed = buildAllowedModelSet({
+    const status = getModelRefStatus({
       cfg: params.cfg,
       catalog: await loadCatalog(),
+      ref: hooksGmailModelRef,
       defaultProvider: resolvedDefault.provider,
       defaultModel: resolvedDefault.model,
     });
-    const key = modelKey(hooksGmailModelRef.provider, hooksGmailModelRef.model);
-    if (allowed.allowAny || allowed.allowedKeys.has(key)) {
+    if (status.allowed) {
       provider = hooksGmailModelRef.provider;
       model = hooksGmailModelRef.model;
     }
@@ -321,34 +319,15 @@ export async function runCronIsolatedAgentTurn(params: {
     if (typeof modelOverrideRaw !== "string") {
       return { status: "error", error: "invalid model: expected string" };
     }
-    const trimmed = modelOverrideRaw.trim();
-    if (!trimmed) {
-      return { status: "error", error: "invalid model: empty" };
-    }
-    const aliasIndex = buildModelAliasIndex({
-      cfg: params.cfg,
-      defaultProvider: resolvedDefault.provider,
-    });
-    const resolvedOverride = resolveModelRefFromString({
-      raw: trimmed,
-      defaultProvider: resolvedDefault.provider,
-      aliasIndex,
-    });
-    if (!resolvedOverride) {
-      return { status: "error", error: `invalid model: ${trimmed}` };
-    }
-    const allowed = buildAllowedModelSet({
+    const resolvedOverride = resolveAllowedModelRef({
       cfg: params.cfg,
       catalog: await loadCatalog(),
+      raw: modelOverrideRaw,
       defaultProvider: resolvedDefault.provider,
       defaultModel: resolvedDefault.model,
     });
-    const key = modelKey(
-      resolvedOverride.ref.provider,
-      resolvedOverride.ref.model,
-    );
-    if (!allowed.allowAny && !allowed.allowedKeys.has(key)) {
-      return { status: "error", error: `model not allowed: ${key}` };
+    if ("error" in resolvedOverride) {
+      return { status: "error", error: resolvedOverride.error };
     }
     provider = resolvedOverride.ref.provider;
     model = resolvedOverride.ref.model;

src/gateway/server.ts

@@ -10,8 +10,7 @@ import {
   resetModelCatalogCacheForTest,
 } from "../agents/model-catalog.js";
 import {
-  buildAllowedModelSet,
-  modelKey,
+  getModelRefStatus,
   resolveConfiguredModelRef,
   resolveHooksGmailModel,
 } from "../agents/model-selection.js";
@@ -1782,22 +1781,21 @@ export async function startGatewayServer(
           defaultModel: DEFAULT_MODEL,
         });
       const catalog = await loadModelCatalog({ config: cfgAtStart });
-      const key = modelKey(hooksModelRef.provider, hooksModelRef.model);
-      const allowed = buildAllowedModelSet({
+      const status = getModelRefStatus({
         cfg: cfgAtStart,
         catalog,
+        ref: hooksModelRef,
         defaultProvider,
         defaultModel,
       });
-      if (!allowed.allowAny && !allowed.allowedKeys.has(key)) {
+      if (!status.allowed) {
         logHooks.warn(
-          `hooks.gmail.model "${key}" not in agents.defaults.models allowlist (will use primary instead)`,
+          `hooks.gmail.model "${status.key}" not in agents.defaults.models allowlist (will use primary instead)`,
         );
       }
-      const inCatalog = catalog.some((e) => modelKey(e.provider, e.id) === key);
-      if (!inCatalog) {
+      if (!status.inCatalog) {
         logHooks.warn(
-          `hooks.gmail.model "${key}" not in the model catalog (may fail at runtime)`,
+          `hooks.gmail.model "${status.key}" not in the model catalog (may fail at runtime)`,
         );
       }
     }

src/gateway/sessions-patch.ts

@@ -3,11 +3,8 @@ import { randomUUID } from "node:crypto";
 import { DEFAULT_MODEL, DEFAULT_PROVIDER } from "../agents/defaults.js";
 import type { ModelCatalogEntry } from "../agents/model-catalog.js";
 import {
-  buildAllowedModelSet,
-  buildModelAliasIndex,
-  modelKey,
+  resolveAllowedModelRef,
   resolveConfiguredModelRef,
-  resolveModelRefFromString,
 } from "../agents/model-selection.js";
 import { normalizeGroupActivation } from "../auto-reply/group-activation.js";
 import {
@@ -168,17 +165,6 @@ export async function applySessionsPatchToStore(params: {
         defaultProvider: DEFAULT_PROVIDER,
         defaultModel: DEFAULT_MODEL,
       });
-      const aliasIndex = buildModelAliasIndex({
-        cfg,
-        defaultProvider: resolvedDefault.provider,
-      });
-      const resolved = resolveModelRefFromString({
-        raw: trimmed,
-        defaultProvider: resolvedDefault.provider,
-        aliasIndex,
-      });
-      if (!resolved) return invalid(`invalid model: ${trimmed}`);
-
       if (!params.loadGatewayModelCatalog) {
         return {
           ok: false,
@@ -189,15 +175,15 @@ export async function applySessionsPatchToStore(params: {
         };
       }
       const catalog = await params.loadGatewayModelCatalog();
-      const allowed = buildAllowedModelSet({
+      const resolved = resolveAllowedModelRef({
         cfg,
         catalog,
+        raw: trimmed,
         defaultProvider: resolvedDefault.provider,
         defaultModel: resolvedDefault.model,
       });
-      const key = modelKey(resolved.ref.provider, resolved.ref.model);
-      if (!allowed.allowAny && !allowed.allowedKeys.has(key)) {
-        return invalid(`model not allowed: ${key}`);
+      if ("error" in resolved) {
+        return invalid(resolved.error);
       }
       if (
         resolved.ref.provider === resolvedDefault.provider &&