Gemini Live API throws 1011: The service is currently unavailable

Gemini API
,
1

Hi team,

I’m testing ephemeral tokens with the Gemini Live API (v1alpha).

Setup

  • Model: gemini-2.0-flash-live-001
  • Token: Created via authTokens.create with liveConnectConstraints and expireTime set to 30 minutes
  • Client: Electron app (Node.js) connecting via WebSocket to
wss://generativelanguage.googleapis.com//ws/google.ai.generativelanguage.v1alpha.GenerativeService.BidiGenerateContentConstrained?access_token=auth_tokens/<mytoken>

Behavior

  • On first connection, the ephemeral token works fine.
  • After ~10 minutes, the WebSocket disconnects (as expected due to connection lifetime limits).
  • I attempt to reconnect using the same ephemeral token (still valid, not expired) and the previous resumptionId.
  • Instead of resuming the session, the server closes immediately with:
The service is currently unavailable

My understanding

  • Documentation suggests ephemeral tokens remain valid until expireTime and should allow resumption within that window.
  • In practice, the token works only for the first session. Any reconnection with the same token and resumption ID fails, even though the token has not expired.

Question

  • Is this expected behavior (ephemeral tokens cannot be reused for session resumption), or is this a bug?
  • If ephemeral tokens are supposed to support multiple reconnects until expiry, what’s the correct way to resume a Live session without creating a new ephemeral token each time?