---
title: "Stop Training Job"
method: POST
path: "/v1/training-jobs/{job_id}/stop"
tags: ["training-jobs"]
---

# Stop Training Job

`POST /v1/training-jobs/{job_id}/stop`

## Request

- Base URL: `https://api.pioneer.ai` (the document declares no server; this is the origin it was published from)
- URL: `https://api.pioneer.ai/v1/training-jobs/{job_id}/stop`
- Auth: one of:
  - API key in header `X-API-Key`
  - HTTP bearer
- TypeScript: <https://skmtc.dev/pioneer/apis/brain-api/docs/v1/training-jobs/:job_id/stop/post.ts> (a function with typed inputs; its response is checked against the schema)

Stop a running training job.

## Path parameters

- `job_id` string, required

## Request body

- StopJobRequest: Optional prune evidence recorded when stopping a training job.
  - `reason` string, nullable: Why this candidate is being stopped
  - `scores` object, nullable: Metric values used to decide the prune
  - `checkpoint` string, nullable: Checkpoint path or step associated with this stop

## Response `200`

Successful Response

- StopJobResponse: Response after stopping a training job
  - `success` boolean, required
  - `message` string, required
  - `job_id` string, required
  - `status` string, required

## Other responses

- `422`: Validation Error

## Changes

- **2026-09-24** `0e5e86e2bae5`: 1 info
  - endpoint added

[Operation history](https://skmtc.dev/pioneer/apis/brain-api/changes/v1/training-jobs/:job_id/stop/post.md)

---

[API](https://skmtc.dev/pioneer/apis/brain-api.md) - [All operations](https://skmtc.dev/pioneer/apis/brain-api/llms.txt) - [OpenAPI document](https://skmtc.dev/pioneer/apis/brain-api/revisions/0e5e86e2bae5?raw)