I’m trying to update an assistant to use a custom Inworld voice, but Vapi returns 400 Bad Request Assistant ID: 13fcc1ad-858e-4582-a68b-ba684dfe46a6 Inworld confirms the voice exists. Payload sent: { "voice": { "provider": "inworld", "voiceId": "voiceidstring", "model": "inworld-tts-1.5-max" } } I also tried adding "languageCode": "en", but it still returned 400. Built-in Inworld voices like Alex work in the same Vapi account, so this seems specific to custom Inworld voice IDs. Can you confirm the correct payload, or check if custom Inworld voice IDs are currently being rejected?

Thank you for sharing your payload and troubleshooting steps. Based on the documentation, your payload structure appears correct for specifying a custom voice (

provider

,

voiceId

, and

model

)—though the docs do not provide a specific example for custom Inworld voices or mention any current rejections of custom IDs ([Vapi docs](https://docs.vapi.ai/providers/voice/inworld), [Custom voices](https://docs.vapi.ai/customization/custom-voices/custom-voice)). To help narrow down the issue: Could you confirm if the custom Inworld voice ID you are using is visible and selectable in the Vapi dashboard under the Voice Configuration section, or is it only available via manual entry/API? Sources: - [Vapi Inworld Voice Provider Documentation](https://docs.vapi.ai/providers/voice/inworld) - [Vapi Custom Voices Documentation](https://docs.vapi.ai/customization/custom-voices/custom-voice)

still haven't gotten a response on this