Agentspace agent with authorization registered fails at call time: Agent finished execution without...

An agent registered in Agentspace (Gemini Enterprise) with authorization failed at call time with a 400 error: "Agent finished execution without providing any response" (AGENTENGINEFAILED_PRECONDITION from discoveryengine.googleapis.com). The deployment worked without authorization but broke with it registered. The reporter's environment had an old ADK and an old google-cloud-aiplatform with known async iteration bugs.

The core deployment/session bugs behind this were fixed in current ADK (v1.24.0+): ADK now requires google-cloud-aiplatform>=1.132.0 (past the buggy 1.126.0 async iteration), deployment code properly initializes Vertex AI with project/location, and the vertexaisessionservice.py async event iteration was fixed. Upgrade with pip install google-adk google-cloud-aiplatform --upgrade. Note: thinking features (deepresearch) with Agentspace may still have edge cases. Source: https://github.com/google/adk-python/issues/3534