api.yaml

openapi: 3.0.0
info:
  title: Event Gate
  version: 0.0.0
  description: This API provides topic management for an event bus.

servers:
  - url: https://{id}-vpce-{vpce}.execute-api.{region}.amazonaws.com/DEV
    variables:
      id:
        default: 01234567ab
        description: API Gateway ID
      vpce:
        default: '01234567abcdef012'
        description: VPC endpoint
      region:
        default: 'af-south-1'
        description: AWS Region

paths:
  /api:
    get:
      summary: Open API specification
      description: Open API specification
      responses:
        '200':
          description: Open API specification
          content:
            application/vnd.oai.openapi:
              schema:
                type: string

  /token:
    get:
      summary: Login to the service
      description: Allows a user to obtain credentials (JWT token) from LoginService for the service
      responses:
        '303':
          description: Redirect to actual address of Login service which performs auth up to its capabilities

  /health:
    get:
      summary: Service health check
      description: Service health and dependency status check
      responses:
        '200':
          description: Service is healthy
          content:
            application/json:
              schema:
                type: object
                properties:
                  status:
                    type: string
                    example: ok
                  uptime_seconds:
                    type: integer
                    example: 12345
        '503':
          description: Service is degraded
          content:
            application/json:
              schema:
                type: object
                properties:
                  status:
                    type: string
                    example: degraded
                  failures:
                    type: object
                    additionalProperties:
                      type: string
                    example:
                      eventbridge: client not initialized
                      kafka: producer not initialized
                      postgres: host not configured

  /topics:
    get:
      summary: Get a list of topics
      description: Returns a list of all available topics.
      responses:
        '200':
          description: A list of topics
          content:
            application/json:
              schema:
                type: array
                items:
                  type: string

  /topics/{topicName}:
    get:
      summary: Get schema for a specific topic
      description: Returns the schema for a specified topic using [JSON Schema](https://json-schema.org/).
      parameters:
        - name: topicName
          in: path
          required: true
          schema:
            type: string
          description: Name of the topic
      responses:
        '200':
          description: Key-value pairs representing the schema for the topic
          content:
            application/json:
              schema:
                type: object
                additionalProperties:
                  type: string
        '404':
          description: Topic not found
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string

    post:
      summary: Publish an event to a topic
      description: Publishes an event to the event bus under the specified topic. User must be authenticated with a JWT token.
      security:
        - bearerAuth: []
      parameters:
        - name: topicName
          in: path
          required: true
          schema:
            type: string
          description: Name of the topic
      requestBody:
        description: Event data to be published
        required: true
        content:
          application/json:
            schema:
              type: object
              additionalProperties: true
      responses:
        '200':
          description: Event successfully published
        '400':
          description: Invalid event data
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
        '401':
          description: Unauthorized
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
        '403':
          description: Forbidden
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
        '404':
          description: Topic not found
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string
                    
  /terminate:
    post:
      summary: Terminates lambda environment
      description: Facilitates fresh start of lambda environment on next invocation (i.e. loads fresh public keys and configs)
      responses:
        '502':
          description: Internal server error or bad gateway error
          content:
            application/json:
              schema:
                type: object
                properties:
                  error:
                    type: string

components:
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT