GitLab Merge trains API

openapi: 3.2.0
info:
  title: GitLab REST Merge trains API
  description: GitLab REST API used to interact with a GitLab installation.
  termsOfService: https://handbook.gitlab.com/handbook/legal/api-terms/
  version: '19.6'
  license:
    name: CC BY-SA 4.0
    url: https://gitlab.com/gitlab-org/gitlab/-/blob/master/LICENSE
    x-gitlab-description: The license applies to the OpenAPI specification document itself. For terms governing use of the GitLab API, see the termsOfService field.
servers:
- url: https://{hostname}
  description: GitLab REST API
  variables:
    hostname:
      default: gitlab.com
      description: Your GitLab instance hostname
security:
- http: []
- oauth2: []
- apiKey: []
tags:
- name: Merge trains
  description: 'Use this API to retrieve the merge trains of a

    project. These endpoints require the Developer, Maintainer, or Owner role, and support

    offset-based pagination.


    Each object in a response represents one merge request in a train, not an entire train. Requesting

    merge trains without a target branch can return entries from more than one train in the project.


    Responses do not include an explicit queue position, and return merge requests as a flat list rather

    than grouped by train:


    - For an exact queue position, sort by `id` in ascending order, or use the GraphQL API

    `MergeTrainCar.index` field.

    - To group merge requests by train, use the `target_branch` attribute, or query the GraphQL API

    `Project.mergeTrains` and

    `MergeTrain.cars` fields.'
  x-displayName: Merge trains
  externalDocs:
    url: https://docs.gitlab.com/api/merge_trains/
paths:
  /api/v4/projects/{id}/merge_trains:
    get:
      operationId: getApiV4ProjectsIdMergeTrains
      summary: List all merge trains for a project
      description: Lists all merge trains for a specified project.
      tags:
      - Merge trains
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/APIEntitiesMergeTrainsCar'
        '401':
          description: Unauthorized
        '403':
          description: Forbidden
        '404':
          description: Not found
        '400':
          description: Bad Request
      parameters:
      - name: id
        required: true
        description: ID or URL-encoded path of the project.
        schema:
          oneOf:
          - type: string
          - type: integer
        in: path
        example: 11
      - name: scope
        required: false
        description: Filter merge trains by scope.
        schema:
          type:
          - string
          - 'null'
          enum:
          - active
          - complete
          - null
        in: query
        example: active
      - name: sort
        required: false
        description: Sort results in ascending or descending order by `id`. A lower `id` value means the merge request was added to the train earlier.
        schema:
          type: string
          enum:
          - asc
          - desc
          default: desc
        in: query
      - name: page
        required: false
        description: Page number of results to retrieve.
        schema:
          type: integer
          default: 1
        in: query
        example: 1
      - name: per_page
        required: false
        description: Number of items to list per page.
        schema:
          type: integer
          default: 20
        in: query
        example: 20
      x-gitlab-tier: premium
  /api/v4/projects/{id}/merge_trains/{target_branch}:
    get:
      operationId: getApiV4ProjectsIdMergeTrainsTargetBranch
      summary: List all merge requests in a merge train
      description: Lists all merge requests in a merge train for a target branch.
      tags:
      - Merge trains
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/APIEntitiesMergeTrainsCar'
        '401':
          description: Unauthorized
        '403':
          description: Forbidden
        '404':
          description: Not found
        '400':
          description: Bad Request
      parameters:
      - name: id
        required: true
        description: ID or URL-encoded path of the project.
        schema:
          oneOf:
          - type: string
          - type: integer
        in: path
        example: 11
      - name: target_branch
        required: true
        description: Target branch of the merge train.
        schema:
          type: string
        in: path
        example: main
      - name: scope
        required: false
        description: Filter merge trains by scope.
        schema:
          type:
          - string
          - 'null'
          enum:
          - active
          - complete
          - null
        in: query
        example: active
      - name: sort
        required: false
        description: Sort results in ascending or descending order by `id`. A lower `id` value means the merge request was added to the train earlier.
        schema:
          type: string
          enum:
          - asc
          - desc
          default: desc
        in: query
      - name: page
        required: false
        description: Page number of results to retrieve.
        schema:
          type: integer
          default: 1
        in: query
        example: 1
      - name: per_page
        required: false
        description: Number of items to list per page.
        schema:
          type: integer
          default: 20
        in: query
        example: 20
      x-gitlab-tier: premium
  /api/v4/projects/{id}/merge_trains/merge_requests/{merge_request_iid}:
    get:
      operationId: getApiV4ProjectsIdMergeTrainsMergeRequestsMergeRequestIid
      summary: Retrieve merge train status
      description: Retrieves the merge train status of a specified merge request.
      tags:
      - Merge trains
      responses:
        '200':
          description: OK
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/APIEntitiesMergeTrainsCar'
        '401':
          description: Unauthorized
        '403':
          description: Forbidden
        '404':
          description: Not found
        '400':
          description: Bad Request
      parameters:
      - name: id
        required: true
        description: ID or URL-encoded path of the project.
        schema:
          oneOf:
          - type: string
          - type: integer
        in: path
        example: 11
      - name: merge_request_iid
        required: true
        description: Internal ID of the merge request.
        schema:
          type: integer
        in: path
      x-gitlab-tier: premium
    post:
      operationId: postApiV4ProjectsIdMergeTrainsMergeRequestsMergeRequestIid
      summary: Add a merge request to a merge train
      description: Adds a specified merge request to a merge train.
      tags:
      - Merge trains
      responses:
        '201':
          description: Created
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/APIEntitiesMergeTrainsCar'
        '202':
          description: Accepted
          content:
            application/json:
              schema:
                type: array
                items:
                  $ref: '#/components/schemas/APIEntitiesMergeTrainsCar'
        '400':
          description: Failed to merge
        '401':
          description: Unauthorized
        '404':
          description: Not found
        '409':
          description: Conflict
        '403':
          description: Forbidden
      parameters:
      - name: id
        required: true
        description: ID or URL-encoded path of the project.
        schema:
          oneOf:
          - type: string
          - type: integer
        in: path
        example: 11
      - name: merge_request_iid
        required: true
        description: Internal ID of the merge request.
        schema:
          type: integer
        in: path
      requestBody:
        required: false
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/postApiV4ProjectsIdMergeTrainsMergeRequestsMergeRequestIidRequest'
      x-gitlab-tier: premium
components:
  schemas:
    APIEntitiesMergeTrainsCar:
      type: object
      properties:
        id:
          type: integer
          format: int64
          example: 38
        merge_request:
          $ref: '#/components/schemas/APIEntitiesMergeRequestSimple'
        user:
          $ref: '#/components/schemas/APIEntitiesUserBasic'
        pipeline:
          $ref: '#/components/schemas/APIEntitiesCiPipelineBasic'
        created_at:
          type: string
          format: date-time
          example: '2015-12-24T15:51:21.880Z'
        updated_at:
          type: string
          format: date-time
          example: '2015-12-24T17:54:31.198Z'
        target_branch:
          type: string
          example: develop
        status:
          type: string
          enum:
          - idle
          - stale
          - fresh
          - merging
          - merged
          - skip_merged
          example: merging
        merged_at:
          type: string
          format: date-time
          example: '2015-12-24T17:54:31.198Z'
        duration:
          type: integer
          description: Time spent in seconds
          example: 127
    APIEntitiesCustomAttribute:
      type: object
      properties:
        key:
          type: string
          example: foo
        value:
          type: string
          example: bar
    postApiV4ProjectsIdMergeTrainsMergeRequestsMergeRequestIidRequest:
      type: object
      properties:
        sha:
          type:
          - string
          - 'null'
          description: SHA that must match the `HEAD` of the source branch, otherwise the merge fails.
        squash:
          type:
          - boolean
          - 'null'
          description: If `true`, the commits are squashed into a single commit on merge.
        when_pipeline_succeeds:
          type:
          - boolean
          - 'null'
          description: '[Deprecated](https://gitlab.com/gitlab-org/gitlab/-/issues/521290) in GitLab 17.11. Use `auto_merge` instead.'
        auto_merge:
          type:
          - boolean
          - 'null'
          description: If `true`, the merge request is added to the merge train when checks pass. If `false` or unspecified, it is added to the merge train immediately.
    APIEntitiesMergeRequestSimple:
      type: object
      properties:
        id:
          type: integer
          format: int64
          example: 84
        iid:
          type: integer
          example: 14
        project_id:
          type: integer
          format: int64
          example: 4
        title:
          type: string
          example: Test MR 1580978354
        description:
          type: string
          example: Repellendus impedit et vel velit dignissimos.
        state:
          type: string
          example: closed
        created_at:
          type: string
          format: date-time
          example: '2022-08-17T12:46:35.053Z'
        updated_at:
          type: string
          format: date-time
          example: '2022-11-14T17:22:01.470Z'
        web_url:
          type: string
          example: http://local.gitlab.test:8181/root/merge-train-race-condition/-/merge_requests/59
    APIEntitiesCiPipelineBasic:
      type: object
      properties:
        id:
          type: integer
          format: int64
          example: 1
        iid:
          type: integer
          example: 2
        project_id:
          type: integer
          format: int64
          example: 3
        sha:
          type: string
          example: 0ec9e58fdfca6cdd6652c083c9edb53abc0bad52
        ref:
          type: string
          example: feature-branch
        status:
          type: string
          example: success
        source:
          type: string
          example: push
        created_at:
          type: string
          format: date-time
          example: '2022-10-21T16:49:48.000+02:00'
        updated_at:
          type: string
          format: date-time
          example: '2022-10-21T16:49:48.000+02:00'
        web_url:
          type: string
          example: https://gitlab.example.com/gitlab-org/gitlab-foss/-/pipelines/61
    APIEntitiesUserBasic:
      type: object
      properties:
        id:
          type: integer
          format: int64
          example: 1
        username:
          type: string
          example: admin
        public_email:
          type: string
          example: john@example.com
        name:
          type: string
          example: Administrator
        state:
          type: string
          example: active
        locked:
          type: boolean
        avatar_url:
          type: string
          example: https://gravatar.com/avatar/1
        avatar_path:
          type: string
          example: /user/avatar/28/The-Big-Lebowski-400-400.png
        custom_attributes:
          type: array
          items:
            $ref: '#/components/schemas/APIEntitiesCustomAttribute'
        web_url:
          type: string
          example: https://gitlab.example.com/root
  securitySchemes:
    http:
      type: http
      scheme: bearer
    oauth2:
      type: oauth2
      flows:
        authorizationCode:
          authorizationUrl: https://gitlab.com/oauth/authorize
          tokenUrl: https://gitlab.com/oauth/token
          refreshUrl: https://gitlab.com/oauth/token
          scopes:
            api: Grants complete read/write access to the API, including all groups and projects, the container registry, the dependency proxy, and the package registry.
            read_api: Grants read access to the API, including all groups and projects, the container registry, and the package registry.
            read_user: Grants read-only access to your profile through the /user API endpoint, which includes username, public email, and full name. Also grants access to read-only API endpoints under /users.
            create_runner: Grants create access to the runners.
            manage_runner: Grants access to manage the runners.
            k8s_proxy: Grants permission to perform Kubernetes API calls using the agent for Kubernetes.
            self_rotate: Grants permission for token to rotate itself.
            mcp: Grants read-write access to remote Model Context Protocol (MCP) server for tools execution.
            mcp_orbit: Grants access to the Orbit Knowledge Graph MCP server for graph queries and schema retrieval.
    apiKey:
      type: apiKey
      name: PRIVATE-TOKEN
      in: header