WebSocket Communication API

asyncapi: 3.0.0
info:
  title: WebSocket Communication API
  version: 1.0.0
  description: >-
    AsyncAPI specification describing WebSocket communication patterns as
    defined by RFC 6455. WebSockets provide full-duplex communication channels
    over a single TCP connection, enabling real-time bidirectional data exchange
    between clients and servers.
  license:
    name: Apache 2.0
    url: https://www.apache.org/licenses/LICENSE-2.0

servers:
  production:
    host: example.com
    protocol: ws
    protocolVersion: '13'
    description: WebSocket server endpoint
  secure:
    host: example.com
    protocol: wss
    protocolVersion: '13'
    description: Secure WebSocket server endpoint (TLS)

channels:
  connection:
    address: /
    description: >-
      The primary WebSocket connection channel. After the opening handshake
      completes, this channel supports full-duplex message exchange using
      text or binary data frames.
    messages:
      textMessage:
        $ref: '#/components/messages/TextMessage'
      binaryMessage:
        $ref: '#/components/messages/BinaryMessage'
      ping:
        $ref: '#/components/messages/Ping'
      pong:
        $ref: '#/components/messages/Pong'
      close:
        $ref: '#/components/messages/Close'

operations:
  sendMessage:
    action: send
    channel:
      $ref: '#/channels/connection'
    summary: Send a message to the WebSocket server
    description: >-
      Sends a text or binary message from client to server over the
      established WebSocket connection.
    messages:
      - $ref: '#/channels/connection/messages/textMessage'
      - $ref: '#/channels/connection/messages/binaryMessage'

  receiveMessage:
    action: receive
    channel:
      $ref: '#/channels/connection'
    summary: Receive a message from the WebSocket server
    description: >-
      Receives a text or binary message from server to client over the
      established WebSocket connection.
    messages:
      - $ref: '#/channels/connection/messages/textMessage'
      - $ref: '#/channels/connection/messages/binaryMessage'

  sendPing:
    action: send
    channel:
      $ref: '#/channels/connection'
    summary: Send a ping frame
    description: >-
      Sends a ping control frame to verify the connection is still alive.
      The remote endpoint must respond with a pong frame.
    messages:
      - $ref: '#/channels/connection/messages/ping'

  receivePong:
    action: receive
    channel:
      $ref: '#/channels/connection'
    summary: Receive a pong frame
    description: >-
      Receives a pong control frame in response to a previously sent ping.
    messages:
      - $ref: '#/channels/connection/messages/pong'

  closeConnection:
    action: send
    channel:
      $ref: '#/channels/connection'
    summary: Initiate connection close
    description: >-
      Sends a close control frame to initiate the WebSocket closing
      handshake as defined in RFC 6455 Section 7.
    messages:
      - $ref: '#/channels/connection/messages/close'

components:
  messages:
    TextMessage:
      name: TextMessage
      title: Text Data Message
      summary: A UTF-8 encoded text message sent over the WebSocket connection
      contentType: text/plain
      payload:
        type: string
        description: UTF-8 encoded text data

    BinaryMessage:
      name: BinaryMessage
      title: Binary Data Message
      summary: A binary message sent over the WebSocket connection
      contentType: application/octet-stream
      payload:
        type: string
        format: binary
        description: Raw binary data

    Ping:
      name: Ping
      title: Ping Control Frame
      summary: >-
        A ping control frame used for keep-alive and connection health checks.
        May include up to 125 bytes of application data.
      payload:
        type: string
        maxLength: 125
        description: Optional application data (up to 125 bytes)

    Pong:
      name: Pong
      title: Pong Control Frame
      summary: >-
        A pong control frame sent in response to a ping. Contains the same
        application data as the ping it is responding to.
      payload:
        type: string
        maxLength: 125
        description: Application data echoed from the corresponding ping frame

    Close:
      name: Close
      title: Close Control Frame
      summary: >-
        A close control frame used to initiate the closing handshake.
        Contains an optional status code and reason string.
      payload:
        $ref: '#/components/schemas/ClosePayload'

  schemas:
    ClosePayload:
      type: object
      description: Payload of a WebSocket close control frame
      properties:
        code:
          type: integer
          description: >-
            A numeric status code indicating the reason for closure as
            defined in RFC 6455 Section 7.4.
          enum:
            - 1000
            - 1001
            - 1002
            - 1003
            - 1007
            - 1008
            - 1009
            - 1010
            - 1011
          examples:
            - 1000
        reason:
          type: string
          maxLength: 123
          description: >-
            A human-readable string explaining the reason for closure.
            Must not be longer than 123 bytes when encoded as UTF-8.