---
title: "Stop Message"
method: POST
path: "/chats/{chatId}/messages/{messageId}/stop"
tags: ["Messages"]
---

# Stop Message

`POST /chats/{chatId}/messages/{messageId}/stop`

Stops an in-flight assistant message generation. The agent aborts at the next safe point and the message is marked finished.

## Path parameters

- `chatId` string, required — The unique identifier of the chat.
- `messageId` string, required — The unique identifier of the assistant message to stop.

## Response `200`

The stopped message.

- object — The stopped message.
  - `messageId` string, required — The unique identifier of the stopped message.

## Other responses

- `401` — Response for status 401
- `403` — Response for status 403
- `404` — Response for status 404
- `409` — Response for status 409
- `422` — Response for status 422
- `500` — Response for status 500

## Changes

- **2026-08-04** `98b36164ce34` — 1 info
  - added the non-success response with the status `422`
- **2026-07-30** `da68370a2aea` — 8 breaking, 13 info
  - for the `path` request parameter `chatId`, the minLength was increased from `0` to `1`
  - for the `path` request parameter `messageId`, the minLength was increased from `0` to `1`
  - removed the required property `error` from the response with the `401` status
  - removed the required property `error` from the response with the `403` status
  - …17 more
- **2026-03-06** `79811cd54faa` — 1 info
  - endpoint added
- **2025-08-24** `3521652a43a7` — 1 breaking
  - api path removed without deprecation

[Change history](https://skmtc.dev/vercel/apis/v0-platform-api-beta/changes/chats/:chatId/messages/:messageId/stop/post.md)

---

[API](https://skmtc.dev/vercel/apis/v0-platform-api-beta.md) · [All operations](https://skmtc.dev/vercel/apis/v0-platform-api-beta/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/vercel/v0-platform-api-beta/revisions/3cf5debd6cf4/schema)