Conversation engine
Choose the AI model that holds an agent's call conversations.
Where to find it
Voice › Agent voice
Open this screen
Steps
- Open Voice › Agent voice and pick the agent in AI agent at the top right.
- Find the Conversation engine card.
- Choose Claude Haiku (Anthropic) or Grok (xAI).
- If a yellow note says the engine's key is not set on the server, that engine cannot answer calls yet; choose the other one or ask the service operator.
- Press Save in the bar at the bottom. Discard changes puts the saved values back.
Settings on this screen
| Setting | What it does | Default |
|---|---|---|
| Conversation engine | The model that answers callers on this agent's calls. | Claude Haiku (Anthropic) |
Troubleshooting
"That conversation engine is not available."
Choose one of the listed engines and save again.
Tips
- The same choice is offered when you use a cloned voice for your agent's calls.
Good to know
- A missing key is said plainly; the page never swaps in another engine on its own.
Related how-tos
- Agent voice Set up one AI agent's voice conversations: its prompt, call voice, engine, transcriber, messages, limits and quick replies.
- Run an agent's calls on Vapi Switched off until an operator turns it on Switch an agent's calls from Grok to the Vapi engine, set up its Vapi assistant and test it.
- Use your cloned voice for calls, or delete it Make your agent speak in your cloned voice, choose the engine that holds the conversation, or delete the voice.