---
title: "Transcription"
method: POST
path: "transcription"
tags: ["Callbacks"]
---

# Transcription

`POST transcription` (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

- TranscriptionEvent
  - `data` Transcription
    - `record_type` 'event' — Identifies the type of the resource.
    - `event_type` 'call.transcription' — The type of event being delivered.
    - `id` string, uuid — Identifies the type of resource.
    - `occurred_at` string, date-time — ISO 8601 datetime of when the event occurred.
    - `payload` object
      - `call_control_id` string — Unique identifier and token for controlling the call.
      - `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 — Use this field to add state to every subsequent webhook. It must be a valid Base-64 encoded string.
      - `connection_id` string — Call Control App ID (formerly Telnyx connection ID) used in the call.
      - `transcription_data` object
        - `confidence` number, float — Speech recognition confidence level.
        - `is_final` boolean — When false, it means that this is an interim result.
        - `transcript` string — Recognized text.
        - `transcription_track` 'inbound' | 'outbound' — Indicates which leg of the call has been transcribed. This is only available when `transcription_engine` is set to `B`.

## 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-2.md) · [All operations](https://skmtc.net/team-telnyx/apis/telnyx-api-2/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/team-telnyx/telnyx-api-2/revisions/8f5f4e537994/schema)