QuizAPI Discovery API

openapi: 3.1.0
info:
  title: Quiz Discovery API
  version: 1.0.0
  description: Access thousands of quiz questions across programming, science, and more. Browse by category, difficulty, and tags.
  contact:
    name: QuizAPI Support
    url: https://quizapi.io
servers:
- url: https://quizapi.io
  description: Production
security: []
tags:
- name: Discovery
  description: Endpoints that require no authentication
paths:
  /api/v1/metadata:
    get:
      summary: Get API metadata
      description: Returns available categories, tags, difficulties, question types, and aggregate stats. No API key required — this is a discovery endpoint.
      tags:
      - Discovery
      responses:
        '200':
          description: Metadata retrieved successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/MetadataResponse'
        '429':
          description: Rate limit exceeded
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
  /api/v1/categories:
    get:
      summary: List topics and categories
      description: Returns the full Topic → Category hierarchy with quiz counts and popular tags per category. Use the returned category `id` as the `categoryId` when creating quizzes. No API key required — this is a discovery endpoint.
      tags:
      - Discovery
      responses:
        '200':
          description: Categories retrieved successfully
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/CategoriesResponse'
        '429':
          description: Rate limit exceeded
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
        '500':
          description: Internal server error
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ErrorResponse'
components:
  schemas:
    CategoriesResponse:
      type: object
      properties:
        success:
          type: boolean
          enum:
          - true
        data:
          type: array
          items:
            $ref: '#/components/schemas/TopicItem'
      required:
      - success
      - data
    TopicItem:
      type: object
      properties:
        id:
          type: string
          example: cm3topic123
        name:
          type: string
          example: Programming
        slug:
          type: string
          example: programming
        icon:
          type:
          - string
          - 'null'
          example: code
        categories:
          type: array
          items:
            $ref: '#/components/schemas/CategoryItem'
      required:
      - id
      - name
      - slug
      - icon
      - categories
      description: A top-level topic containing categories
    MetadataResponse:
      type: object
      properties:
        success:
          type: boolean
          enum:
          - true
        data:
          type: object
          properties:
            difficulties:
              type: array
              items:
                $ref: '#/components/schemas/Difficulty'
              example:
              - EASY
              - MEDIUM
              - HARD
              - EXPERT
            questionTypes:
              type: array
              items:
                $ref: '#/components/schemas/QuestionType'
              example:
              - MULTIPLE_CHOICE
              - TRUE_FALSE
              - OPEN_ENDED
            categories:
              type: array
              items:
                type: string
              example:
              - Programming
              - DevOps
              - Science
            tags:
              type: array
              items:
                type: string
              example:
              - javascript
              - python
              - docker
            stats:
              type: object
              properties:
                totalQuizzes:
                  type: integer
                  example: 150
                totalQuestions:
                  type: integer
                  example: 3200
              required:
              - totalQuizzes
              - totalQuestions
          required:
          - difficulties
          - questionTypes
          - categories
          - tags
          - stats
      required:
      - success
      - data
    ErrorResponse:
      type: object
      properties:
        success:
          type: boolean
          enum:
          - false
        error:
          type: string
          example: Something went wrong.
      required:
      - success
      - error
      description: Standard error response
    CategoryItem:
      type: object
      properties:
        id:
          type: string
          example: cm3cat789
        name:
          type: string
          example: Python
        slug:
          type: string
          example: python
        quizCount:
          type: integer
          example: 12
        tags:
          type: array
          items:
            type: string
          maxItems: 20
          example:
          - python
          - basics
          - data-structures
          description: Popular tags used in quizzes within this category (maximum 20 tags)
      required:
      - id
      - name
      - slug
      - quizCount
      - tags
      description: A category within a topic
    Difficulty:
      type: string
      enum:
      - EASY
      - MEDIUM
      - HARD
      - EXPERT
      description: Difficulty level of a quiz or question
    QuestionType:
      type: string
      enum:
      - MULTIPLE_CHOICE
      - TRUE_FALSE
      - OPEN_ENDED
      description: The type of question
  securitySchemes:
    BearerAuth:
      type: http
      scheme: bearer
      description: 'Pass your API key as a Bearer token: `Authorization: Bearer qza_live_...`. Alternatively, use the `api_key` query parameter.'