---
title: "Cancel a journey run"
method: POST
path: "/projects/{projectId}/journey-runs/{runId}/cancel"
tags: ["Swarm runs"]
---

# Cancel a journey run

`POST /projects/{projectId}/journey-runs/{runId}/cancel`

Stops a run and settles its in-flight attempts. IDEMPOTENT: cancelling an already-cancelled run answers 200 with `alreadyCanceled: true` and `finalized: 0`, not a 409.

Addressed entirely by the path `runId` — there is no body.

Deliberately NOT behind the beta gate: cancelling REDUCES exposure and spend, so an organization that loses the flag can still stop a run that is under way.

## Response `200`

The run was cancelled (or already was).

- JourneyRunCanceled
  - `id` string, required
  - `status` string, required — The run's terminal status after the cancel settled it.
  - `canceled` true, required
  - `alreadyCanceled` boolean, required — True when the run was already cancelled and this call did nothing.
  - `finalized` integer, required — Attempts this call moved to terminal. Zero on an idempotent replay.

## Other responses

- `401` — Missing, invalid, revoked, or orphaned key (`UNAUTHORIZED`) — or the **target MCP server** needs an OAuth grant (`OAUTH_REQUIRED`), which is a property of the server, not your key.
- `403` — Key is valid but not allowed to do this.
- `404` — Unknown project, server, or resource.
- `409` — The resource is not in a state that accepts this write — a stale `expectedRevision`, a duplicate name, or an environment that cannot currently be launched. The request was well-formed; re-read the resource and retry.
- `429` — Per-key rate limit exceeded (60 requests/minute sustained, bursts up to 10). Honor `Retry-After` and back off with jitter.
- `500` — Something failed on MCPJam's side.

---

[API](https://skmtc.net/mcpjam/apis/mcpjam-api.md) · [All operations](https://skmtc.net/mcpjam/apis/mcpjam-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/mcpjam/mcpjam-api/revisions/8978a4e735fa/schema)