diff --git a/src/features/background-agent/types.ts b/src/features/background-agent/types.ts
index 5edbe102d..3c5928872 100644
--- a/src/features/background-agent/types.ts
+++ b/src/features/background-agent/types.ts
@@ -43,6 +43,8 @@ export interface BackgroundTask {
   result?: string
   error?: string
   progress?: TaskProgress
+  /** Current session state cached from polling (e.g., 'idle', 'running', 'retry') */
+  sessionState?: string
   parentModel?: { providerID: string; modelID: string }
   model?: DelegatedModelConfig
   /** Fallback chain for runtime retry on model errors */