Gemini 3.8 Live Extended Thinking emits no toolCall for a NON_BLOCKING function

Gemini API
,
1

I can reproduce missing native function calls in Gemini 3.8 Live Extended Thinking on one API key. Setup succeeds and the model hears/responds, but no toolCall event arrives. The same key and function work on standard Gemini 3.8 Live.

Environment: Gemini Developer Live API (v1beta; raw v1alpha also tested), @google/genai JavaScript SDK 2.24.0, 25 September 2026.

Minimal SDK config:

const config = {
  responseModalities: [Modality.AUDIO],
  thinkingConfig: { thinkingLevel: 'low' },
  tools: [{ functionDeclarations: [{
    name: 'diagnostic_echo',
    description: 'Return a fixed harmless echo token.',
    behavior: 'NON_BLOCKING',
    parameters: {
      type: 'OBJECT',
      properties: { nonce: { type: 'STRING' } },
      required: ['nonce']
    }
  }] }]
};
const session = await ai.live.connect({ model: 'gemini-3.8-live-extended-thinking', config, callbacks });
session.sendClientContent({ turns: { role: 'user', parts: [{ text: 'Please call diagnostic_echo with nonce 237 now, then say ECHO_OK.' }] }, turnComplete: true });

Observed with Extended LOW: setup acknowledged; audio and IN_PROGRESS then IDLE received; 0 toolCall events and 0 API errors. includeThoughts=true also produced no tool call or thought summary. Standard gemini-3.8-live with the same key, NON_BLOCKING function and request emitted a toolCall with an ID.

I also tested a verified 5.8-second 16 kHz mono PCM spoken request on raw v1beta: Extended with NON_BLOCKING heard the input and reached IDLE without toolCall; standard 3.8 with BLOCKING emitted diagnostic_echo with an ID, accepted the matching toolResponse, and completed. Extended also skipped the sole function on raw v1alpha. In a production voice app, real action requests produce a spoken “system error” apology and no function call or WebSocket error.

Expected: Extended emits toolCall.functionCalls with a call ID before final IDLE and accepts the matching toolResponse, as described in the Thinking in the Live API guide. Can the Live API team confirm whether Extended async function calling is currently available on all Gemini Developer API keys, or identify a required field missing from the documented setup? No API key or personal user data is included here.

2

I also have tried for several times and it keeps giving me "I apologize, but a system error occurred while trying to process " the STATUS: IDLE was defined and also tool call with “behavior”: “NON_BLOCKING” has defined as google described and also tried without peramitter and also tried many different ways and told to fix (GPT 6 Astra, Claude Oups 5.5, and Gemini 3.8 flash)
though Gemini 3.8 flash somehow managed to get it working before 5 hours but now its failing

Yesterday:

Tools: [ ‘get_weather’, ‘list_directory’, ‘read_file’ ]

Warning: Ephemeral token support is experimental and may change in future versions.

-– Turn 1: Weather —

রংপুরের আবহাওয়া কেমন তা দেখে নিচ্ছি।

>>> TOOL CALL RECEIVED: {“functionCalls”:[{“name”:“get_weather”,“args”:{“location”:“Rangpur”},“id”:“call_49083_fc_0_0”}]}

[Orvix Live Tool: get_weather] Called with: { location: ‘Rangpur’ } → Cleaned location: “Rangpur”

[Orvix Live Tool: get_weather] Resolved place: Rangpur, Bangladesh (25.7439, 89.2752)

রংপুরের বর্তমান আবহাওয়া পরিষ্কার। তাপমাত্রা প্রায় ২৫.৭ ডিগ্রি সেলসিয়াস, যা অনুভূত হচ্ছে ৩১.৩ ডিগ্রি সেলসিয়াসের মতো। বাতাসের আর্দ্রতা ৯৩% এবং বাতাসের গতিবেগ ঘণ্টায় প্রায় ৫.৩ কিলোমিটার। আজকের সর্বোচ্চ তাপমাত্রা ৩১.৪ ডিগ্রি এবং সর্বনিম্ন তাপমাত্রা ২৪.৪ ডিগ্রি সেলসিয়াস।

[IDLE]

Now :

[TEST PROFILE]: Thinking (depth: LOW)
CLOSE: 1000
Warning: Ephemeral token support is experimental and may change in future versions.
Sending query: “What folders are on my Desktop?”
Let me check those files for you.I am sorry, but a system error occurred.
Result: :cross_mark: FAILED (Spoke: Let me check those files for you.I am sorry, but a system error occurred.)
CLOSE: 1000