diff --git a/apps/server/src/services/domain/admin/router-config/index.ts b/apps/server/src/services/domain/admin/router-config/index.ts
index 5021411ee..05c6177cb 100644
--- a/apps/server/src/services/domain/admin/router-config/index.ts
+++ b/apps/server/src/services/domain/admin/router-config/index.ts
@@ -25,6 +25,11 @@ const DEFAULT_KEY_ENTRY_IDS = {
   'unspeech': 'volcengine-prod-1',
 } as const
 
+const DEFAULT_FALLBACK_TRIGGERS = {
+  httpCodes: [401, 402, 403, 429, 500, 502, 503, 504],
+  onTimeout: true,
+}
+
 type LlmRouterConfig = InferOutput<typeof llmRouterConfigSchema>
 type LlmModel = InferOutput<typeof llmModelSchema>
 type TtsModel = InferOutput<typeof ttsModelSchema>
@@ -162,7 +167,8 @@ export function buildOpenRouterSlice(input: OpenRouterSliceInput, envelope: Enve
         keys: [{ id: keyEntryId, ciphertext }],
         headerTemplate: input.headerTemplate ?? 'Bearer {KEY}',
       }],
-    } as LlmModel,
+      fallbackTriggers: DEFAULT_FALLBACK_TRIGGERS,
+    },
   }
 }
 
@@ -194,7 +200,8 @@ export function buildAzureSlice(input: AzureSliceInput, envelope: EnvelopeCrypto
           ...(input.defaultVoice ? { defaultVoice: input.defaultVoice } : {}),
         },
       }],
-    } as TtsModel,
+      fallbackTriggers: DEFAULT_FALLBACK_TRIGGERS,
+    },
   }
 }
 
@@ -232,7 +239,8 @@ export function buildDashscopeSlice(input: DashscopeSliceInput, envelope: Envelo
         keys: [{ id: keyEntryId, ciphertext }],
         adapterParams: { model: input.upstreamModel },
       }],
-    } as TtsModel,
+      fallbackTriggers: DEFAULT_FALLBACK_TRIGGERS,
+    },
   }
 }
 
diff --git a/apps/server/src/services/domain/admin/router-config/tests/admin-router-config.test.ts b/apps/server/src/services/domain/admin/router-config/tests/admin-router-config.test.ts
index 595bd96bd..970d3de67 100644
--- a/apps/server/src/services/domain/admin/router-config/tests/admin-router-config.test.ts
+++ b/apps/server/src/services/domain/admin/router-config/tests/admin-router-config.test.ts
@@ -21,6 +21,11 @@ function freshEnvelope() {
   return createEnvelopeCrypto({ masterKey: randomBytes(32) })
 }
 
+const DEFAULT_FALLBACK_TRIGGERS = {
+  httpCodes: [401, 402, 403, 429, 500, 502, 503, 504],
+  onTimeout: true,
+}
+
 interface FakeConfigKV {
   store: Map<string, unknown>
   service: ConfigKVService
@@ -112,6 +117,7 @@ describe('buildOpenRouterSlice', () => {
     expect(upstream.baseURL).toBe('https://openrouter.ai/api/v1')
     expect(upstream.overrideModel).toBe('openai/gpt-4o-mini')
     expect(upstream.headerTemplate).toBe('Bearer {KEY}')
+    expect(built.model.fallbackTriggers).toEqual(DEFAULT_FALLBACK_TRIGGERS)
 
     // Round-trip the ciphertext under the same AAD — guards against the
     // AAD getting silently changed (which would surface as DECRYPT_FAILED
@@ -161,6 +167,7 @@ describe('buildAzureSlice', () => {
       region: 'eastasia',
       defaultVoice: 'en-US-AvaMultilingualNeural',
     })
+    expect(built.model.fallbackTriggers).toEqual(DEFAULT_FALLBACK_TRIGGERS)
 
     const decrypted = envelope.decryptKey(built.model.upstreams[0].keys[0].ciphertext, {
       modelName: 'microsoft/v1',
@@ -186,6 +193,7 @@ describe('buildDashscopeSlice', () => {
 
     expect(built.model.upstreams[0].baseURL).toBe(`https://${host}/api/v1/services/audio/tts/SpeechSynthesizer`)
     expect(built.model.upstreams[0].adapterParams).toEqual({ model: 'cosyvoice-v2' })
+    expect(built.model.fallbackTriggers).toEqual(DEFAULT_FALLBACK_TRIGGERS)
   })
 })
 
@@ -232,8 +240,23 @@ describe('buildNextRouterConfig', () => {
   it('merge mode preserves models not touched this run', () => {
     const envelope = freshEnvelope()
     const existing = {
-      llm: { models: { 'untouched-chat': { upstreams: [{ baseURL: 'https://old', keys: [{ id: 'k', ciphertext: 'c' }], headerTemplate: 'Bearer {KEY}' }] } } },
-      tts: { models: { 'untouched-tts': { provider: 'azure' as const, upstreams: [{ baseURL: 'https://old-tts', keys: [{ id: 'k', ciphertext: 'c' }], adapterParams: {} }] } } },
+      llm: {
+        models: {
+          'untouched-chat': {
+            upstreams: [{ baseURL: 'https://old', keys: [{ id: 'k', ciphertext: 'c' }], headerTemplate: 'Bearer {KEY}' }],
+            fallbackTriggers: DEFAULT_FALLBACK_TRIGGERS,
+          },
+        },
+      },
+      tts: {
+        models: {
+          'untouched-tts': {
+            provider: 'azure' as const,
+            upstreams: [{ baseURL: 'https://old-tts', keys: [{ id: 'k', ciphertext: 'c' }], adapterParams: {} }],
+            fallbackTriggers: DEFAULT_FALLBACK_TRIGGERS,
+          },
+        },
+      },
       defaults: { perAttemptTimeoutMs: 12345, fullChainTimeoutMs: 60000, fallbackHttpCodes: [500] },
     }
     const newSlice = buildOpenRouterSlice({
@@ -256,7 +279,14 @@ describe('buildNextRouterConfig', () => {
   it('reset mode drops every prior entry and uses default timeouts', () => {
     const envelope = freshEnvelope()
     const existing = {
-      llm: { models: { old: { upstreams: [{ baseURL: 'https://old', keys: [{ id: 'k', ciphertext: 'c' }], headerTemplate: 'Bearer {KEY}' }] } } },
+      llm: {
+        models: {
+          old: {
+            upstreams: [{ baseURL: 'https://old', keys: [{ id: 'k', ciphertext: 'c' }], headerTemplate: 'Bearer {KEY}' }],
+            fallbackTriggers: DEFAULT_FALLBACK_TRIGGERS,
+          },
+        },
+      },
       tts: { models: {} },
       defaults: { perAttemptTimeoutMs: 12345, fullChainTimeoutMs: 60000, fallbackHttpCodes: [500] },
     }