I’m testing the new xAI TTS integration in LiveKit Agents and consistently getting TTS failures in a normal voice-agent flow. What I’m seeing The agent generates text, but TTS fails with: failed to synthesize speech: message=‘Invalid response status’, status_code=403, retryable=False and then: l…

What version of LiveKit and plugins are you running pip freeze |grep livekit Also can you share the code where you set up the LLM,TTS, and STT?

I face the same issue with grok TTS. Unrecoverable error from TTS: type=‘tts_error’ timestamp=1775022717.850421 label=‘livekit.plugins.xai.tts.TTS’ error=APIError('no audio frames were pushed for text

@Rishiikesh_Balaji to avoid potential issues with your API key validity, can you try xAI with Inference? If that works, it’s a strong indication there is an issue with the key. 403 usually indicates an error like this.

@darryncampbell Thanks for the response. We currently have an xAI api key with a $5 in credits. we were able to hit all the REST API xAI apis through postman and python as well. But we were unable to use the same XAI_API_KEY to get response from the X_AI model through livekit plugin. We are using s…

It’s working through Inference for me, but I’m unable to test with the plugin until I have a key. Let me get a key and then I can try with the Plugin.

Sure. Let me know if you find anything

I think there are different issues being discussed in this thread. Status code 403 typically indicates an issue with the key I am seeing a status code 400 when I try using the plugin, failed to synthesize speech. To me it looks like an issue with the plugin, but since the plugin was only recently…

The team are working on a fix for this, (xai tts): update fields and ws setup by tinalenguyen · Pull Request #5350 · livekit/agents · GitHub . Thank you for raising this @Rishiikesh_Balaji . Also @Vrishabh_Kumar , re-reading your original post, you will also be affected by this update

The fix mentioned above has been included in the latest Agents release: [image] Python livekit-agents@1.5.2 released Agents livekit-agents@1.5.2 Note livekit-agents 1.5 introduced many new features. You can check out the changelog here . What’s Changed Upda…

xAI TTS returns 403 and no audio frames pushed; plugin appears to use different WebSocket endpoint than xAI docs

Agents

darryncampbell (Darryn) April 9, 2026, 9:06am 11

The fix mentioned above has been included in the latest Agents release:

Topic		Replies	Views
ElevenLabs STT & TTS plugin both broken on LiveKit Agents v1.4.4 Agents stt , tts	5	193	April 15, 2026
Python livekit-agents@1.4.6 Released Agents agent-development	0	43	March 17, 2026
Voxtral TTS API 1,230ms TTFB in real-time voice agent pipeline Agents tts , mistralai	3	74	April 6, 2026
Add api ElevenLabs key to agents TTS Getting Started	4	34	March 26, 2026
TTS/STT Inference fails due to APIConnectionError with no clear error message Agents stt , tts , node-js	4	65	March 8, 2026

xAI TTS returns 403 and no audio frames pushed; plugin appears to use different WebSocket endpoint than xAI docs

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