Tool/Function Call

Called **BEFORE** an inbound call is answered, allowing you to: - Dynamically configure the assistant based on caller information - Personalize the greeting message - Override STT/LLM/TTS configuration - Set call-specific analysis plans - Reject calls based on business logic (e.g., outside business hours) - Pass custom metadata that will be echoed in all subsequent webhook events ⚠️ **Important:** Your endpoint must respond within **5 seconds** or the call will proceed with default agent configuration. ### Response Modes **1. Default mode** - Use saved agent config: ```json {} ``` **2. Transient agent** - Full config override: ```json { "assistant": { "first_message": "Hello John!", "tts_config": {"voice_id": "..."}, "metadata": {"crm_id": "12345"} } } ``` **3. Hybrid agent** - Reference saved agent + overrides: ```json { "assistant_id": "uuid-of-saved-agent", "assistant_override": { "tts_config": {"voice_id": "female-voice"}, "first_message": "Hello John!", "metadata": {"crm_id": "12345"} } } ``` The hybrid mode uses **shallow merge**: each top-level key in `assistant_override` completely replaces that config block from the saved agent. ### Custom Metadata Any fields you add to the assistant config (like `metadata`) will be echoed back in all subsequent webhook events (`status-update`, `tool-calls`, `end-of-call-report`). This is useful for passing CRM IDs, campaign info, or any context you need.