diff --git a/src/config/schema/runtime-fallback.ts b/src/config/schema/runtime-fallback.ts
index 6c25a113..3089d28b 100644
--- a/src/config/schema/runtime-fallback.ts
+++ b/src/config/schema/runtime-fallback.ts
@@ -9,6 +9,8 @@ export const RuntimeFallbackConfigSchema = z.object({
   max_fallback_attempts: z.number().min(1).max(20).optional(),
   /** Cooldown in seconds before retrying a failed model (default: 60) */
   cooldown_seconds: z.number().min(0).optional(),
+  /** Session-level timeout in seconds to advance fallback when provider hangs (default: 30) */
+  timeout_seconds: z.number().min(1).optional(),
   /** Show toast notification when switching to fallback model (default: true) */
   notify_on_fallback: z.boolean().optional(),
 })
diff --git a/src/hooks/runtime-fallback/constants.ts b/src/hooks/runtime-fallback/constants.ts
index e0ea1fb5..a49831fb 100644
--- a/src/hooks/runtime-fallback/constants.ts
+++ b/src/hooks/runtime-fallback/constants.ts
@@ -14,6 +14,7 @@ export const DEFAULT_CONFIG: Required<RuntimeFallbackConfig> = {
   retry_on_errors: [400, 429, 503, 529],
   max_fallback_attempts: 3,
   cooldown_seconds: 60,
+  timeout_seconds: 30,
   notify_on_fallback: true,
 }
 
diff --git a/src/hooks/runtime-fallback/types.ts b/src/hooks/runtime-fallback/types.ts
index 3ff6334a..5cb28504 100644
--- a/src/hooks/runtime-fallback/types.ts
+++ b/src/hooks/runtime-fallback/types.ts
@@ -58,6 +58,8 @@ export interface RuntimeFallbackOptions {
   config?: RuntimeFallbackConfig
   /** Optional plugin config override (primarily for testing) */
   pluginConfig?: OhMyOpenCodeConfig
+  /** Optional session-level timeout override in milliseconds (primarily for testing) */
+  session_timeout_ms?: number
 }
 
 export interface RuntimeFallbackHook {