> ## Documentation Index
> Fetch the complete documentation index at: https://staging.docs.trywhitney.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Preempt a current primitive and submit a terminal cancel transition.



## OpenAPI

````yaml /openapi.yaml post /v1/training/runs/{run_id}/cancel
openapi: 3.1.0
info:
  title: Whitney Training API
  version: 0.3.0
  description: >
    Public HTTP API for caller-owned model training on Whitney.


    Authenticate with a Whitney API key (`whitney_test_…` or `whitney_live_…`).

    Create a session and run, submit ordered training and sampling primitives,

    poll durable operations, and retrieve checkpoints, artifacts, usage, and
    cost.


    Every public request uses typed JSON. Token IDs and dense tensor values are

    ordinary JSON arrays validated against strict, provider-neutral schemas.
servers:
  - url: http://localhost:3001
    description: Local API
  - url: https://api.staging.trywhitney.com
    description: Staging API
  - url: https://api.trywhitney.com
    description: Production API
security:
  - WhitneyApiKey: []
tags:
  - name: unified-training
    description: Whitney-owned session, primitive, and operations API.
paths:
  /v1/training/runs/{run_id}/cancel:
    parameters:
      - $ref: '#/components/parameters/RunId'
    post:
      tags:
        - unified-training
      summary: Preempt a current primitive and submit a terminal cancel transition.
      operationId: cancelTrainingRun
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/CancelRunRequest'
      responses:
        '202':
          description: Durable cancel operation handle.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Operation'
        default:
          $ref: '#/components/responses/ApiError'
components:
  parameters:
    RunId:
      name: run_id
      in: path
      required: true
      schema:
        $ref: '#/components/schemas/RunId'
  schemas:
    CancelRunRequest:
      allOf:
        - $ref: '#/components/schemas/RequestIdBody'
        - type: object
          properties:
            reason:
              type:
                - string
                - 'null'
              maxLength: 500
    Operation:
      type: object
      additionalProperties: false
      required:
        - id
        - session_id
        - run_id
        - seq_id
        - kind
        - status
        - result
        - error_code
        - progress
        - progress_updated_at
        - created_at
        - updated_at
      properties:
        id:
          $ref: '#/components/schemas/OperationId'
        session_id:
          $ref: '#/components/schemas/SessionId'
        run_id:
          $ref: '#/components/schemas/RunId'
        seq_id:
          type: integer
          minimum: 1
        kind:
          type: string
          enum:
            - forward
            - forward_backward
            - optim_step
            - save_state
            - load_state
            - save_weights_for_sampler
            - export_lora
            - sample
            - logprobs
            - finish
            - cancel
        status:
          type: string
          enum:
            - parked
            - pending
            - executing
            - succeeded
            - failed
            - cancelled
        result:
          type:
            - object
            - 'null'
          additionalProperties: true
        error_code:
          type:
            - string
            - 'null'
        progress:
          type:
            - object
            - 'null'
          additionalProperties: true
        progress_updated_at:
          oneOf:
            - $ref: '#/components/schemas/Timestamp'
            - type: 'null'
        created_at:
          $ref: '#/components/schemas/Timestamp'
        updated_at:
          $ref: '#/components/schemas/Timestamp'
    RunId:
      type: string
      pattern: ^wtr_[0-9a-f]{32}$
    RequestIdBody:
      type: object
      additionalProperties: false
      required:
        - request_id
      properties:
        request_id:
          type: string
          minLength: 1
          maxLength: 200
    OperationId:
      type: string
      pattern: ^wto_[0-9a-f]{32}$
    SessionId:
      type: string
      pattern: ^wts_[0-9a-f]{32}$
    Timestamp:
      type: string
      format: date-time
    ErrorResponse:
      type: object
      additionalProperties: false
      required:
        - error
      properties:
        error:
          type: object
          additionalProperties: false
          required:
            - code
            - message
          properties:
            code:
              type: string
            message:
              type: string
        request_id:
          type: string
        funding_source:
          type: string
          enum:
            - platform
            - byok
  responses:
    ApiError:
      description: Whitney API error envelope.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
  securitySchemes:
    WhitneyApiKey:
      type: http
      scheme: bearer
      bearerFormat: whitney_test_|whitney_live_
      description: Whitney-issued API key. No organization-selection header is accepted.

````