---
title: "Conference Participant Playback Started"
method: POST
path: "conferenceParticipantPlaybackStarted"
tags: ["Callbacks"]
---

# Conference Participant Playback Started

`POST conferenceParticipantPlaybackStarted` (webhook)

This webhook uses Telnyx headers (telnyx-timestamp, telnyx-signature-ed25519) that are compatible with Standard Webhooks specification for SDK generation. Custom validation logic can map these to standard webhook-timestamp and webhook-signature equivalents. See https://github.com/standard-webhooks/standard-webhooks for details.

## Headers

- `telnyx-timestamp` integer, required — Unix timestamp for replay attack prevention
- `telnyx-signature-ed25519` string, required — Ed25519 signature of timestamp|payload for verification

## Payload

- ConferenceParticipantPlaybackStartedEvent
  - `data` ConferenceParticipantPlaybackStarted
    - `record_type` 'event' — Identifies the type of the resource.
    - `event_type` 'conference.participant.playback.started' — The type of event being delivered.
    - `id` string, uuid — Identifies the type of resource.
    - `payload` object
      - `call_control_id` string — Participant's call ID used to issue commands via Call Control API.
      - `call_leg_id` string — ID that is unique to the call and can be used to correlate webhook events.
      - `call_session_id` string — ID that is unique to the call session and can be used to correlate webhook events. Call session is a group of related call legs that logically belong to the same phone call, e.g. an inbound and outbound leg of a transferred call.
      - `client_state` string — State received from a command.
      - `connection_id` string — Call Control App ID (formerly Telnyx connection ID) used in the call.
      - `creator_call_session_id` string — ID that is unique to the call session that started the conference.
      - `conference_id` string — ID of the conference the text was spoken in.
      - `media_url` string — The audio URL being played back, if audio_url has been used to start.
      - `media_name` string — The name of the audio media file being played back, if media_name has been used to start.
      - `occurred_at` string, date-time — ISO 8601 datetime of when the event occurred.

## Acknowledgement `200`

The server must return an HTTP 200, otherwise we will reattempt delivery at the failover webhook URL.

---

[API](https://skmtc.net/team-telnyx/apis/telnyx-api.md) · [All operations](https://skmtc.net/team-telnyx/apis/telnyx-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/team-telnyx/telnyx-api/versions/e32d46c5945b/schema)