Stability AI Stable Image Control API

openapi: 3.1.0
info:
  title: Stability AI Stable Image Control API
  description: >-
    The Stability AI Stable Image Control API provides image-to-image generation
    guided by structural inputs such as sketches, reference structures, and style
    guides. Using ControlNet-based models, developers can generate new images that
    follow the composition, edges, or layout of a source image while applying new
    styles or content based on text prompts. The API supports sketch-to-image,
    structure-guided generation, and style transfer workflows.
  version: 'v2beta'
  contact:
    name: Stability AI Support
    url: https://platform.stability.ai
  termsOfService: https://stability.ai/terms-of-service
externalDocs:
  description: Stability AI API Documentation
  url: https://platform.stability.ai/docs/api-reference
servers:
  - url: https://api.stability.ai
    description: Production Server
tags:
  - name: Sketch
    description: >-
      Generate images from hand-drawn sketches or line drawings, guided by a
      text prompt to fill in details, colors, and textures.
  - name: Structure
    description: >-
      Generate images guided by the structural composition of a reference image,
      preserving edges and layout while applying new content from a text prompt.
  - name: Style
    description: >-
      Generate images that adopt the visual style of a reference image while
      following a text prompt for content direction.
security:
  - bearerAuth: []
paths:
  /v2beta/stable-image/control/sketch:
    post:
      operationId: controlImageSketch
      summary: Generate an image from a sketch
      description: >-
        Generates a detailed image from a hand-drawn sketch or line drawing.
        The sketch provides the structural composition while the text prompt
        guides the content, colors, textures, and style of the output image.
      tags:
        - Sketch
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              $ref: '#/components/schemas/SketchControlRequest'
      responses:
        '200':
          description: Successfully generated image from sketch
          content:
            image/jpeg:
              schema:
                type: string
                format: binary
            image/png:
              schema:
                type: string
                format: binary
            image/webp:
              schema:
                type: string
                format: binary
            application/json:
              schema:
                $ref: '#/components/schemas/ControlImageResponse'
        '400':
          description: Bad request due to invalid parameters
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Unauthorized due to missing or invalid API key
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '403':
          description: >-
            Forbidden due to content moderation or insufficient permissions
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '429':
          description: Rate limit exceeded
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
  /v2beta/stable-image/control/structure:
    post:
      operationId: controlImageStructure
      summary: Generate an image guided by structural reference
      description: >-
        Generates a new image guided by the structural composition of a reference
        image. The reference image provides edge and layout information while the
        text prompt directs the content and style of the output. Useful for
        generating variations that maintain the same composition.
      tags:
        - Structure
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              $ref: '#/components/schemas/StructureControlRequest'
      responses:
        '200':
          description: Successfully generated structurally guided image
          content:
            image/jpeg:
              schema:
                type: string
                format: binary
            image/png:
              schema:
                type: string
                format: binary
            image/webp:
              schema:
                type: string
                format: binary
            application/json:
              schema:
                $ref: '#/components/schemas/ControlImageResponse'
        '400':
          description: Bad request due to invalid parameters
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Unauthorized due to missing or invalid API key
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '403':
          description: >-
            Forbidden due to content moderation or insufficient permissions
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '429':
          description: Rate limit exceeded
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
  /v2beta/stable-image/control/style:
    post:
      operationId: controlImageStyle
      summary: Generate an image with style transfer
      description: >-
        Generates a new image that adopts the visual style of a reference image.
        The style image provides color palette, artistic technique, and aesthetic
        direction while the text prompt controls the subject and composition of
        the output.
      tags:
        - Style
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              $ref: '#/components/schemas/StyleControlRequest'
      responses:
        '200':
          description: Successfully generated style-transferred image
          content:
            image/jpeg:
              schema:
                type: string
                format: binary
            image/png:
              schema:
                type: string
                format: binary
            image/webp:
              schema:
                type: string
                format: binary
            application/json:
              schema:
                $ref: '#/components/schemas/ControlImageResponse'
        '400':
          description: Bad request due to invalid parameters
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '401':
          description: Unauthorized due to missing or invalid API key
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '403':
          description: >-
            Forbidden due to content moderation or insufficient permissions
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '429':
          description: Rate limit exceeded
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        API key authentication. Pass your Stability AI API key as a Bearer token
        in the Authorization header.
  schemas:
    SketchControlRequest:
      type: object
      required:
        - image
        - prompt
      properties:
        image:
          type: string
          format: binary
          description: >-
            The sketch or line drawing image to use as structural guidance.
        prompt:
          type: string
          maxLength: 10000
          description: >-
            Text describing the desired output image including content, colors,
            textures, and style.
        negative_prompt:
          type: string
          maxLength: 10000
          description: >-
            Text describing elements to exclude from the output image.
        control_strength:
          type: number
          minimum: 0
          maximum: 1
          default: 0.7
          description: >-
            Controls how closely the output follows the input sketch. Higher
            values produce outputs more faithful to the sketch structure.
        seed:
          type: integer
          minimum: 0
          maximum: 4294967294
          default: 0
          description: >-
            A value to control randomness in generation.
        output_format:
          type: string
          enum:
            - jpeg
            - png
            - webp
          default: png
          description: >-
            The output format of the generated image.
    StructureControlRequest:
      type: object
      required:
        - image
        - prompt
      properties:
        image:
          type: string
          format: binary
          description: >-
            The reference image to use for structural guidance. The edges and
            layout of this image will guide the output composition.
        prompt:
          type: string
          maxLength: 10000
          description: >-
            Text describing the desired output image content and style.
        negative_prompt:
          type: string
          maxLength: 10000
          description: >-
            Text describing elements to exclude from the output image.
        control_strength:
          type: number
          minimum: 0
          maximum: 1
          default: 0.7
          description: >-
            Controls how closely the output follows the reference structure.
            Higher values produce outputs more faithful to the reference layout.
        seed:
          type: integer
          minimum: 0
          maximum: 4294967294
          default: 0
          description: >-
            A value to control randomness in generation.
        output_format:
          type: string
          enum:
            - jpeg
            - png
            - webp
          default: png
          description: >-
            The output format of the generated image.
    StyleControlRequest:
      type: object
      required:
        - image
        - prompt
      properties:
        image:
          type: string
          format: binary
          description: >-
            The style reference image whose visual style will be applied to the
            output.
        prompt:
          type: string
          maxLength: 10000
          description: >-
            Text describing the subject and composition of the output image.
        negative_prompt:
          type: string
          maxLength: 10000
          description: >-
            Text describing elements to exclude from the output image.
        fidelity:
          type: number
          minimum: 0
          maximum: 1
          default: 0.5
          description: >-
            Controls how strongly the style of the reference image influences
            the output. Higher values produce outputs closer to the reference
            style.
        seed:
          type: integer
          minimum: 0
          maximum: 4294967294
          default: 0
          description: >-
            A value to control randomness in generation.
        output_format:
          type: string
          enum:
            - jpeg
            - png
            - webp
          default: png
          description: >-
            The output format of the generated image.
    ControlImageResponse:
      type: object
      properties:
        image:
          type: string
          description: >-
            Base64-encoded image data when Accept header is set to
            application/json.
        finish_reason:
          type: string
          enum:
            - SUCCESS
            - CONTENT_FILTERED
          description: >-
            The reason the generation finished.
        seed:
          type: integer
          description: >-
            The seed used for generation.
    ErrorResponse:
      type: object
      properties:
        id:
          type: string
          description: >-
            A unique identifier for the error instance.
        name:
          type: string
          description: >-
            The error type name.
        message:
          type: string
          description: >-
            A human-readable description of the error.