Vapi Recall

Vapi webhook: returns concise caller context for the AI agent.

Dispatches by message.type. Only handles tool-calls events; other event types Vapi posts to the same server URL (status-update, conversation-update, transcript, etc.) get a benign 200 response so Vapi keeps the assistant alive rather than dropping context.

Vapi tool result MUST be a single string per https://docs.vapi.ai/tools/custom-tools-troubleshooting — any non-string result is silently dropped by Vapi.