openapi: 3.2.0
info:
  title: Kann KI das? OAuth API
  version: 1.1.0
  description: Faceted product search plus machine-readable availability and buyer-confirmed Stripe Checkout for fixed sponsor placements.
servers:
- url: https://kannkidas.de/api
tags:
- name: OAuth
paths:
  /oauth/token:
    post:
      operationId: issueAgentAccessToken
      summary: Issue an opaque access token using client credentials
      security:
      - clientBasic: []
      requestBody:
        required: true
        content:
          application/x-www-form-urlencoded:
            schema:
              type: object
              required:
              - grant_type
              properties:
                grant_type:
                  const: client_credentials
                scope:
                  type: string
                  default: sponsorship:read
      responses:
        '200':
          description: Short-lived bearer token
        '401':
          description: Invalid client
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
      tags:
      - OAuth
components:
  schemas:
    Error:
      type: object
      required:
      - message
      properties:
        message:
          type: string
  securitySchemes:
    clientBasic:
      type: http
      scheme: basic
    oauth2:
      type: oauth2
      flows:
        clientCredentials:
          tokenUrl: https://kannkidas.de/api/oauth/token
          scopes:
            sponsorship:read: Read own purchase status
            sponsorship:write: Create a confirmed checkout