Voices

Two ways to give your agent a voice

You never have to bring a key. The default pipeline already speaks every language. Bring your own only when you want a specific premium voice or a provider’s real-time engine.

Use the default (nothing to do)

Open any agent’s voice settings at bithuman.ai. The bitHuman voice section is marked Included — design a voice, clone one, or pick from the gallery. It’s multilingual automatically, so there’s no language toggle to manage.

Clone a voice

Cloning, designing and previewing voices is free.

1. Open the agent’s voice settings in the bitHuman app and choose Clone Voice.
2. Upload or record 30 seconds or more of clean speech from one speaker, with no music. Longer clean samples are fine; the whole file is used.
3. Select Clone Voice and keep the window open. Cloning takes about a minute.
4. Select Preview to hear the new voice.
5. Select Apply to Agent. Until you apply it, the agent keeps its previous voice.

To clone from the API instead, send the sample as audio when you create an agent.

Check the voice your agent uses

• In the bitHuman app: open the agent’s voice settings and select Preview. It plays the voice saved on the agent.
• With the API: GET /v1/agent/{code} returns the saved voice as data.voice_id.

curl https://api.bithuman.ai/v1/agent/$AGENT_CODE -H "api-secret: $BITHUMAN_API_SECRET"

{"success": true, "data": {"code": "A80HVD8577", "language": "en", "voice_id": "bf0a246a-8642-498a-9950-80c35e9276b5"}}

Change the voice

Change an agent’s voice in the bitHuman app: apply a clone, a designed voice or a gallery voice in the agent’s voice settings. The API cannot set the voice; POST /v1/agent/{code} changes only the prompt and the voice providers.

Realtime mode uses its own voice. With Realtime mode on, or an OpenAI or Grok real-time voice selected, the agent speaks that provider’s voice instead of the saved voice. To use your clone, turn Realtime mode off in the agent’s Providers settings and save. To clear a real-time voice from the API, send {"providers": {"realtime": "default"}} to POST /v1/agent/{code}.

Bring your own voice provider

1. Connect your key

Go to Developer → Integrations, add your provider, and paste that provider’s key; bitHuman checks the key there before saving and rejects an invalid one. The Providers API stores a key as sent, without a check, so start one session to confirm it works. Keys are encrypted at rest and never leave the platform in plaintext.

2. Pick a premium voice

Back in the agent’s voice settings, the premium providers you’ve connected unlock. Choose a voice; a provider you haven’t connected stays locked with a shortcut to Integrations. Your selection runs that voice on your key.

Supported providers

Tip Real-time providers (OpenAI, Grok) give the lowest-latency, most expressive speech-to-speech — great for kiosks and live demos. ElevenLabs and Cartesia give you a specific voice on the standard pipeline.

How billing works

• Every managed-agent conversation bills the voice chat rate, whichever voice it uses (pricing).
• A bring-your-own voice or real-time model is also billed by your provider on your key.

If a bring-your-own key ever fails or is removed, the agent automatically falls back to the built-in multilingual pipeline — it never silently stops talking.

Troubleshooting