---
title: "Add a named marker to an in-progress recording"
method: POST
path: "/recording/mark"
---

# Add a named marker to an in-progress recording

`POST /recording/mark`

Records a named point in time during an active recording. At finalize the markers are injected into the output MP4 as chapter markers.

## Request body

- MarkRecordingRequest
  - `name` string, required — Name of the marker, used as the MP4 chapter title.
  - `id` string — Identifier of the recording session to mark, as passed to /recording/start. Alphanumeric or hyphen. When omitted, the marker is added to the default recording session.

## Response `201`

Marker recorded

- MarkRecordingResult
  - `name` string, required — Name of the recorded marker.
  - `offset_ms` integer, required — Provisional offset of the marker from the recording start, in milliseconds, measured against the start time at mark time. The authoritative offset is the chapter start written at finalize.

## Other responses

- `400` — Bad Request
- `404` — Not Found
- `409` — Conflict
- `500` — Internal Server Error

## Changes

- **2026-07-27** `7c85ebb7d5ef` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/kernel/apis/kernel-images-api/changes/recording/mark/post.md)

---

[API](https://skmtc.dev/kernel/apis/kernel-images-api.md) · [All operations](https://skmtc.dev/kernel/apis/kernel-images-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/kernel/kernel-images-api/revisions/7a641fa15a85/schema)