### Payload

The payload of this webhook request is an object.

- **chat_group_id** *string* (Required)
  - Unique ID of the **Chat Group** associated with the **Chat** session.

- **chat_id** *string* (Required)
  - Unique ID of the **Chat** session.

- **config_id** *string or null* (Required)
  - Unique ID of the EVI **Config** used for the session.

- **caller_number** *string or null* (Required)
  - Phone number of the caller in E.164 format (e.g., `+12223333333`). This field is included only if the Chat was created via the [Twilio phone calling](https://dev.hume.ai/docs/empathic-voice-interface-evi/phone-calling) integration.

- **custom_session_id** *string or null* (Required)
  - User-defined session ID. Relevant only when employing a [custom language model](https://dev.hume.ai/docs/empathic-voice-interface-evi/custom-language-model) in the EVI Config.

- **duration_seconds** *integer* (Required)
  - Total duration of the session in seconds.

- **end_reason** *enum* (Required)
  - Reason for the session's termination.
  - Show 7 enum values

- **end_time** *integer* (Required)
  - Unix timestamp (in milliseconds) indicating when the session ended.

- **twilio_metadata** *map from strings to strings or null* (Required)
  - Twilio metadata associated with the chat. This field is included only if the Chat was created via the [Twilio phone calling](https://dev.hume.ai/docs/empathic-voice-interface-evi/phone-calling) integration. Fields may include `call_sid`, `account_sid`, `from_number`, `to_number`, `caller_name`, `caller_number`, `from_city`, `from_state`, `from_zip`, `from_country`, `to_city`, `to_state`, `to_zip`, and `to_country`. If a specific metadata is not available, this field will be set to an empty string.

- **event_name** *"chat_ended"* (Optional)
  - Defaults to `chat_ended`.

### Response

200

- any  
  - Return a 200 status to indicate that the data was received successfully.