[Feature Request] Gemini 2.5 / 3.1 realtime (Live API) support

[SimonKrivda]

Is your feature request related to a problem? Please describe.

Runner.runLive() and GeminiLlmConnection currently only support Gemini 2.0 Flash Live. Gemini 2.5 Flash and 3.1 Flash Live preview models are not supported — attempts to use them result in silent failures or incompatible connection behaviour. This blocks production use of newer, higher-quality models in voice/realtime agent applications.

Describe the solution you'd like

Full support for gemini-2.5-flash-preview-native-audio and gemini-3.1-flash-live-preview (and future Live-capable models) in the ADK JS live bridge — including sendRealtimeInput, receive(), and turn/interruption handling compatible with those models' protocol. An ETA or tracking issue for this would be very helpful.

Describe alternatives you've considered

Forking @google/adk and patching GeminiLlmConnection directly (as we are currently doing) to fix audio blob sending and keep receive() open across turns. This is not sustainable long-term as it requires manually rebasing against upstream releases.

Additional context

We are building a production voice agent using ADK JS with Runner.runLive(). Gemini 2.5 and 3.1 Live models offer significantly better quality for Czech-language voice interactions, which is critical for our use case. The lack of official support is a blocker for us moving off the fork.

[tSte]

I think this is the same as #239 (opened ~6 weeks ago) but there is no activity by maintainers. I even opened #325 mimicking Python ADK about two weeks ago, but nobody responded / reviewed :(

[Varun-S10]

Hi @SimonKrivda, Thank you for sharing this with us, we really appreciate it and will escalate it to the team. Thank you for your patience and understanding.

Hi @cornellgit, I would like to escalate this user request to add support for Gemini 2.5 and 3.1 realtime (Live API) models