---
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.fastino.ai`
- URL: `https://api.fastino.ai/v1/training/jobs/{job_id}/stop`
- Auth: one of:
  - API key in header `X-API-Key`
  - HTTP bearer

Stop a running training job (an interactive job releases its adapter; its checkpoints are kept).

## Path parameters

- `job_id` string, required

## Request body

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

## Response `200`

Successful Response

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

## Other responses

- `202`: Cancellation in progress.
- `409`: The cancel did not land. `error.code` is `training_job_already_finished` when the job completed or failed first, or `cancellation_unconfirmed` when it may be retried.
- `422`: Validation Error

## Changes

- **2026-10-13** `5ebfd9fe8f46`: 1 info
  - endpoint added

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

---

[API](https://skmtc.dev/fastino-ai/apis/pioneer-inference-api.md) - [All operations](https://skmtc.dev/fastino-ai/apis/pioneer-inference-api/llms.txt) - [OpenAPI document](https://skmtc.dev/fastino-ai/apis/pioneer-inference-api/revisions/81465e18c1d2?raw)