Cataas Cats API

openapi: 3.0.3
info:
  title: Cataas Admin Cats API
  version: 1.0.0
  description: CATAAS (Cat as a Service) is a free, no-authentication REST API that returns random cat images and GIFs with optional tags, filters, sizing, and text overlays. It is an open-source project published under the GitHub cataas organization (https://github.com/cataas/cataas) and is consumed primarily as image URLs that can be embedded directly into HTML, README files, and chat applications.
  contact:
    name: CATAAS Project
    url: https://github.com/cataas/cataas
  license:
    name: Open Source (no SPDX declared)
    url: https://github.com/cataas/cataas
  x-generated-from: documentation
  x-last-validated: '2026-05-30'
servers:
- url: https://cataas.com
  description: Public production API
tags:
- name: Cats
  description: Random and tagged cat image retrieval
paths:
  /cat:
    get:
      operationId: getRandomCat
      summary: CATAAS Get a Random Cat Image
      description: Returns a random cat image. By default the response is the binary image payload; pass `json=true` to receive a metadata JSON document with an `_id`, `tags`, `mimetype`, and a `url` you can embed.
      tags:
      - Cats
      parameters:
      - $ref: '#/components/parameters/json'
      - $ref: '#/components/parameters/html'
      - $ref: '#/components/parameters/type'
      - $ref: '#/components/parameters/width'
      - $ref: '#/components/parameters/height'
      - $ref: '#/components/parameters/fit'
      - $ref: '#/components/parameters/position'
      - $ref: '#/components/parameters/filter'
      - $ref: '#/components/parameters/blur'
      - $ref: '#/components/parameters/brightness'
      - $ref: '#/components/parameters/lightness'
      - $ref: '#/components/parameters/saturation'
      - $ref: '#/components/parameters/hue'
      - $ref: '#/components/parameters/red'
      - $ref: '#/components/parameters/green'
      - $ref: '#/components/parameters/blue'
      responses:
        '200':
          description: A random cat image (binary) or metadata document
          content:
            image/jpeg:
              schema:
                type: string
                format: binary
            image/png:
              schema:
                type: string
                format: binary
            image/gif:
              schema:
                type: string
                format: binary
            application/json:
              schema:
                $ref: '#/components/schemas/Cat'
        '404':
          $ref: '#/components/responses/NotFound'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /cat/{tag}:
    get:
      operationId: getRandomCatByTag
      summary: CATAAS Get a Random Cat Image by Tag
      description: Returns a random cat image that carries the provided tag (or any of the comma-separated tags supplied). Supports the same sizing, filter, and JSON/HTML response negotiation as `/cat`.
      tags:
      - Cats
      parameters:
      - name: tag
        in: path
        required: true
        description: 'One tag or several comma-separated tags. Example: `cute` or `cute,orange`.'
        schema:
          type: string
        example: cute
      - $ref: '#/components/parameters/json'
      - $ref: '#/components/parameters/html'
      - $ref: '#/components/parameters/type'
      - $ref: '#/components/parameters/width'
      - $ref: '#/components/parameters/height'
      - $ref: '#/components/parameters/fit'
      - $ref: '#/components/parameters/position'
      - $ref: '#/components/parameters/filter'
      - $ref: '#/components/parameters/blur'
      responses:
        '200':
          description: A random tagged cat image
          content:
            image/jpeg:
              schema:
                type: string
                format: binary
            application/json:
              schema:
                $ref: '#/components/schemas/Cat'
        '404':
          $ref: '#/components/responses/NotFound'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /cat/gif:
    get:
      operationId: getRandomCatGif
      summary: CATAAS Get a Random Cat GIF
      description: Returns a random animated cat (image/gif). Same query parameters as `/cat` may be used for sizing and JSON negotiation. Filters do not apply to GIFs.
      tags:
      - Cats
      parameters:
      - $ref: '#/components/parameters/json'
      - $ref: '#/components/parameters/html'
      - $ref: '#/components/parameters/width'
      - $ref: '#/components/parameters/height'
      responses:
        '200':
          description: A random cat GIF
          content:
            image/gif:
              schema:
                type: string
                format: binary
            application/json:
              schema:
                $ref: '#/components/schemas/Cat'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /cat/says/{text}:
    get:
      operationId: getRandomCatSays
      summary: CATAAS Get a Random Cat Image with Text Overlay
      description: Returns a random cat image with the supplied text rendered on top. Use `fontSize`, `fontColor`, and `fontBackground` to style the overlay. URL-encode any special characters in `text`.
      tags:
      - Cats
      parameters:
      - name: text
        in: path
        required: true
        description: Text to overlay onto the image.
        schema:
          type: string
        example: hello world
      - $ref: '#/components/parameters/fontSize'
      - $ref: '#/components/parameters/fontColor'
      - $ref: '#/components/parameters/fontBackground'
      - $ref: '#/components/parameters/json'
      - $ref: '#/components/parameters/html'
      - $ref: '#/components/parameters/type'
      - $ref: '#/components/parameters/filter'
      responses:
        '200':
          description: A random cat image with overlay
          content:
            image/jpeg:
              schema:
                type: string
                format: binary
            application/json:
              schema:
                $ref: '#/components/schemas/Cat'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /cat/{tag}/says/{text}:
    get:
      operationId: getRandomCatByTagSays
      summary: CATAAS Get a Random Tagged Cat with Text Overlay
      description: Returns a random cat image that carries `tag` and renders `text` on top. Combines the behavior of `/cat/{tag}` and `/cat/says/{text}`.
      tags:
      - Cats
      parameters:
      - name: tag
        in: path
        required: true
        description: One or more comma-separated tags.
        schema:
          type: string
        example: cute
      - name: text
        in: path
        required: true
        description: Text to overlay onto the image.
        schema:
          type: string
        example: hello world
      - $ref: '#/components/parameters/fontSize'
      - $ref: '#/components/parameters/fontColor'
      - $ref: '#/components/parameters/fontBackground'
      - $ref: '#/components/parameters/json'
      responses:
        '200':
          description: A random tagged cat image with overlay
          content:
            image/jpeg:
              schema:
                type: string
                format: binary
            application/json:
              schema:
                $ref: '#/components/schemas/Cat'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /cat/{id}:
    get:
      operationId: getCatById
      summary: CATAAS Get a Specific Cat Image by Id
      description: Returns the cat image identified by `id`. The id is the MongoDB document id surfaced in catalog (`/api/cats`) responses.
      tags:
      - Cats
      parameters:
      - name: id
        in: path
        required: true
        description: Catalog id of the cat document.
        schema:
          type: string
        example: 595f280b557291a9750ebf66
      - $ref: '#/components/parameters/json'
      - $ref: '#/components/parameters/html'
      - $ref: '#/components/parameters/type'
      - $ref: '#/components/parameters/filter'
      responses:
        '200':
          description: The requested cat image
          content:
            image/jpeg:
              schema:
                type: string
                format: binary
            application/json:
              schema:
                $ref: '#/components/schemas/Cat'
        '404':
          $ref: '#/components/responses/NotFound'
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
  /cat/{id}/says/{text}:
    get:
      operationId: getCatByIdSays
      summary: CATAAS Get a Specific Cat with Text Overlay
      description: Returns the cat image identified by `id` with `text` rendered on top.
      tags:
      - Cats
      parameters:
      - name: id
        in: path
        required: true
        description: Catalog id of the cat document.
        schema:
          type: string
        example: 595f280b557291a9750ebf66
      - name: text
        in: path
        required: true
        description: Text to overlay onto the image.
        schema:
          type: string
        example: hello world
      - $ref: '#/components/parameters/fontSize'
      - $ref: '#/components/parameters/fontColor'
      - $ref: '#/components/parameters/fontBackground'
      responses:
        '200':
          description: The cat image with overlay
          content:
            image/jpeg:
              schema:
                type: string
                format: binary
      x-microcks-operation:
        delay: 0
        dispatcher: FALLBACK
components:
  parameters:
    fit:
      name: fit
      in: query
      required: false
      description: Resize strategy when both width and height are provided.
      schema:
        type: string
        enum:
        - cover
        - contain
        - fill
        - inside
        - outside
      example: cover
    red:
      name: r
      in: query
      required: false
      description: Red channel multiplier (0-255) for `filter=custom`.
      schema:
        type: integer
        minimum: 0
        maximum: 255
      example: 200
    saturation:
      name: saturation
      in: query
      required: false
      description: Saturation multiplier for `filter=custom`.
      schema:
        type: number
        minimum: 0
        maximum: 100
      example: 1.5
    lightness:
      name: lightness
      in: query
      required: false
      description: Lightness offset for `filter=custom`.
      schema:
        type: number
        minimum: -100
        maximum: 100
      example: 0
    type:
      name: type
      in: query
      required: false
      description: Sized variant of the image.
      schema:
        type: string
        enum:
        - xsmall
        - small
        - medium
        - square
        - sq
      example: small
    hue:
      name: hue
      in: query
      required: false
      description: Hue rotation in degrees for `filter=custom`.
      schema:
        type: integer
        minimum: -360
        maximum: 360
      example: 60
    width:
      name: width
      in: query
      required: false
      description: Resize the image to the specified width in pixels (max 1000).
      schema:
        type: integer
        minimum: 1
        maximum: 1000
      example: 400
    height:
      name: height
      in: query
      required: false
      description: Resize the image to the specified height in pixels (max 1000).
      schema:
        type: integer
        minimum: 1
        maximum: 1000
      example: 400
    json:
      name: json
      in: query
      required: false
      description: When `true`, return a JSON metadata document instead of the binary image.
      schema:
        type: boolean
      example: true
    filter:
      name: filter
      in: query
      required: false
      description: Visual filter applied to the image.
      schema:
        type: string
        enum:
        - blur
        - mono
        - negate
        - custom
      example: mono
    green:
      name: g
      in: query
      required: false
      description: Green channel multiplier (0-255) for `filter=custom`.
      schema:
        type: integer
        minimum: 0
        maximum: 255
      example: 100
    fontBackground:
      name: fontBackground
      in: query
      required: false
      description: Background color behind the overlay text.
      schema:
        type: string
      example: black
    fontSize:
      name: fontSize
      in: query
      required: false
      description: Font size in pixels for `/says/` text overlays.
      schema:
        type: integer
        minimum: 8
        maximum: 200
      example: 50
    fontColor:
      name: fontColor
      in: query
      required: false
      description: Font color name or hex value (e.g., `red`, `#ffffff`).
      schema:
        type: string
      example: white
    blur:
      name: blur
      in: query
      required: false
      description: Blur radius when `filter=blur`.
      schema:
        type: number
        minimum: 0
        maximum: 100
      example: 5
    brightness:
      name: brightness
      in: query
      required: false
      description: Brightness multiplier for `filter=custom`.
      schema:
        type: number
        minimum: 0
        maximum: 100
      example: 1.2
    html:
      name: html
      in: query
      required: false
      description: When `true`, return an HTML page that embeds the image.
      schema:
        type: boolean
      example: false
    position:
      name: position
      in: query
      required: false
      description: Position of the cropped image when `fit=cover` or `fit=contain`.
      schema:
        type: string
        enum:
        - top
        - right top
        - right
        - right bottom
        - bottom
        - left bottom
        - left
        - left top
        - center
        - centre
        - entropy
        - attention
      example: center
    blue:
      name: b
      in: query
      required: false
      description: Blue channel multiplier (0-255) for `filter=custom`.
      schema:
        type: integer
        minimum: 0
        maximum: 255
      example: 50
  responses:
    NotFound:
      description: Requested cat or resource was not found
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/ErrorResponse'
          examples:
            NotFoundExample:
              summary: Default 404 response
              x-microcks-default: true
              value:
                error:
                  name: NotFoundError
                  message: Cat not found
  schemas:
    ErrorResponse:
      title: ErrorResponse
      type: object
      description: Generic error response.
      required:
      - error
      properties:
        error:
          type: object
          description: Error details.
          properties:
            name:
              type: string
              description: Error class name.
              example: NotFoundError
            message:
              type: string
              description: Human-readable error description.
              example: Cat not found
    Cat:
      title: Cat
      type: object
      description: A cat catalog document.
      required:
      - id
      - tags
      properties:
        _id:
          type: string
          description: MongoDB document id of the cat.
          example: 595f280b557291a9750ebf66
        id:
          type: string
          description: Public id of the cat (mirror of `_id`).
          example: 595f280b557291a9750ebf66
        tags:
          type: array
          description: Tags attached to this cat.
          items:
            type: string
          example:
          - cute
          - orange
        mimetype:
          type: string
          description: MIME type of the cat image file.
          example: image/jpeg
        size:
          type: integer
          description: Size of the cat image file in bytes.
          example: 18234
        created_at:
          type: string
          format: date-time
          description: Timestamp when the cat document was created.
          example: '2026-05-29T14:30:00Z'
        edited_at:
          type: string
          format: date-time
          description: Timestamp when the cat document was last edited.
          example: '2026-05-29T15:00:00Z'
        validated:
          type: boolean
          description: Whether this cat has been moderated and approved for the public catalog.
          example: true
        url:
          type: string
          format: uri
          description: Direct URL to the cat image.
          example: https://cataas.com/cat/595f280b557291a9750ebf66
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
      description: Admin-only bearer token for moderation and catalog management.