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

# Start a run



## OpenAPI

````yaml /api/openapi.json post /api/v1/nodes/{nodeId}/runs
openapi: 3.0.2
info:
  title: Melius API
  version: '1'
  description: >-
    The Melius REST API. Authenticate with an API key as a bearer token
    (`Authorization: Bearer mel_...`) and select the team to act on with the
    `x-team-id` header. Generations run through the same node + run pipeline as
    the app: create a node on a canvas, start a run, poll the run, then read the
    resulting version asset.
servers:
  - url: https://api.melius.com
security:
  - apiKey: []
    teamId: []
paths:
  /api/v1/nodes/{nodeId}/runs:
    post:
      tags:
        - run
      summary: Start a run
      operationId: run.start
      parameters:
        - name: nodeId
          in: path
          required: true
          schema:
            type: string
            format: uuid
      requestBody:
        description: Body
        content:
          application/json:
            schema:
              type: object
              properties:
                canvasId:
                  type: string
                  format: uuid
                textPrompt:
                  type: string
                modelConfig:
                  type: object
                  properties:
                    model:
                      type: string
                    variant:
                      type: string
                    tier:
                      type: string
                      nullable: true
                    font:
                      type: object
                      properties:
                        source:
                          type: string
                          enum:
                            - custom
                            - google
                        familyName:
                          type: string
                      required:
                        - source
                        - familyName
                  required:
                    - model
                    - variant
                outputAspectRatio:
                  type: string
                  enum:
                    - '21:9'
                    - '16:9'
                    - '4:3'
                    - '5:4'
                    - '3:2'
                    - '1:1'
                    - '2:3'
                    - '3:4'
                    - '4:5'
                    - '9:16'
                    - '9:21'
                outputDuration:
                  type: integer
                  minimum: 0
                  exclusiveMinimum: true
                outputResolution:
                  oneOf:
                    - type: string
                      enum:
                        - 360p
                        - 480p
                        - 540p
                        - 580p
                        - 720p
                        - 1080p
                        - 1440p
                        - 2160p
                        - 4k
                        - 0.5K
                        - 1K
                        - 2K
                        - 4K
                        - 1k
                        - 2k
                    - type: string
                seed:
                  type: integer
                  minimum: 0
                  maximum: 2147483647
                numVariations:
                  type: integer
                  minimum: 1
                  maximum: 10
                generateAudio:
                  type: boolean
                negativePrompt:
                  type: string
                imageUrls:
                  type: array
                  items:
                    type: string
                    format: uri
                  maxItems: 15
                elevenLabsVoiceId:
                  type: string
                  minLength: 1
                customVoiceId:
                  type: string
                  format: uuid
                elevenLabsVoiceSettings:
                  type: object
                  properties:
                    speed:
                      type: number
                      minimum: 0.25
                      maximum: 4
                    stability:
                      type: number
                      minimum: 0
                      maximum: 1
                    similarityBoost:
                      type: number
                      minimum: 0
                      maximum: 1
                    style:
                      type: number
                      minimum: 0
                      maximum: 1
                    speakerBoost:
                      type: boolean
                    removeBackgroundNoise:
                      type: boolean
                    outputFormat:
                      type: string
                      enum:
                        - mp3_44100_128
                        - mp3_44100_192
                        - mp3_22050_32
                        - pcm_16000
                        - pcm_22050
                        - pcm_24000
                        - pcm_44100
      responses:
        '201':
          description: '201'
          content:
            application/json:
              schema:
                type: object
                properties:
                  id:
                    type: string
                    format: uuid
                required:
                  - id
        '202':
          description: '202'
          content:
            application/json:
              schema:
                type: object
                properties:
                  approvalId:
                    type: string
                    format: uuid
                required:
                  - approvalId
        '400':
          description: '400'
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                required:
                  - message
        '401':
          description: Missing, invalid, expired, or revoked API key.
          content:
            application/json:
              schema:
                type: object
                properties:
                  statusCode:
                    type: integer
                  error:
                    type: string
                  message:
                    type: string
                required:
                  - statusCode
                  - message
        '403':
          description: The API key's user is not a member of the requested team.
          content:
            application/json:
              schema:
                type: object
                properties:
                  statusCode:
                    type: integer
                  error:
                    type: string
                  message:
                    type: string
                required:
                  - statusCode
                  - message
        '404':
          description: '404'
          content:
            application/json:
              schema:
                type: object
                properties:
                  message:
                    type: string
                required:
                  - message
        '429':
          description: Rate limit reached — retry after the `Retry-After` header.
          headers:
            Retry-After:
              description: Seconds to wait before retrying.
              schema:
                type: integer
          content:
            application/json:
              schema:
                type: object
                properties:
                  statusCode:
                    type: integer
                  error:
                    type: string
                  message:
                    type: string
                  retryAfterSeconds:
                    type: integer
                required:
                  - statusCode
                  - message
components:
  securitySchemes:
    apiKey:
      type: http
      scheme: bearer
      description: 'A Melius API key (`mel_...`), sent as `Authorization: Bearer <key>`.'
    teamId:
      type: apiKey
      in: header
      name: x-team-id
      description: The team (workspace) to act on. Defaults to the key's team when omitted.

````