PubNub REST API

asyncapi: '2.6.0'
id: 'urn:com:pubnub:realtime'
info:
  title: PubNub Realtime Streaming API
  version: '3.0.0'
  description: |
    AsyncAPI description of PubNub's realtime subscribe surface — the event stream
    that delivers messages, signals, presence updates, file events, message-action
    events, and App Context (object) events to subscribed clients.

    Transport note (important honesty disclaimer):
    PubNub's official public wire protocol is NOT WebSocket. The Subscribe API is
    delivered over HTTPS as a long-lived long-poll request against ps.pndsn.com.
    The SDK issues a GET subscribe request; the network either returns immediately
    with a batch of events (HTTP 200 with a JSON envelope) or holds the request
    until a long-poll expiration (~280 seconds) and returns an empty batch, after
    which the SDK reissues the request using the most recent timetoken.

    AsyncAPI is used here to model the EVENT-LEVEL contract (channels, message
    schemas, presence/object/message-action events) that the SDK exposes to
    application code via listeners. The underlying transport binding is HTTP
    long-poll, not WebSocket. PubNub's own documentation describes only the
    SDK-level listener event objects publicly; the lower-level wire envelope
    (t/m/e/a/f/i/p/k/c/d/b/u fields) is not formally published and is therefore
    not modeled in this spec to avoid fabrication.

    Source documentation:
    - https://www.pubnub.com/docs/general/setup/connection-management
    - https://www.pubnub.com/docs/general/presence/presence-events
    - https://www.pubnub.com/docs/general/metadata/basics
    - https://www.pubnub.com/docs/sdks/javascript/api-reference/publish-and-subscribe
    - https://www.pubnub.com/docs/sdks/javascript/api-reference/message-actions

    Authentication: publish/subscribe key pair (per keyset). Optional Access
    Manager auth token via the auth query parameter.
  contact:
    name: PubNub Support
    url: https://support.pubnub.com/
  license:
    name: PubNub Terms of Service
    url: https://www.pubnub.com/legal/terms-of-service/
  termsOfService: https://www.pubnub.com/legal/terms-of-service/

defaultContentType: application/json

servers:
  production:
    url: ps.pndsn.com
    protocol: https
    description: |
      PubNub production edge endpoint. The Subscribe API is a long-poll HTTPS GET
      under the path /v2/subscribe/{sub-key}/{channels}/0. Despite the realtime
      semantics modeled by this AsyncAPI document, the underlying binding is
      HTTPS, NOT WebSocket.

channels:
  message:
    description: |
      Standard published messages delivered to all subscribers of a channel.
      Received by SDK listeners as a "message" event.
    subscribe:
      summary: Receive published messages on a channel.
      operationId: receiveMessage
      message:
        $ref: '#/components/messages/Message'

  signal:
    description: |
      Lightweight signals delivered to subscribers of a channel. Signals are
      capped at 64 bytes of payload and are intended for high-volume, low-latency
      use cases. Received by SDK listeners as a "signal" event.
    subscribe:
      summary: Receive signals on a channel.
      operationId: receiveSignal
      message:
        $ref: '#/components/messages/Signal'

  presence:
    description: |
      Presence events for a channel, delivered on the {channel}-pnpres
      companion channel. Event types include join, leave, timeout, state-change,
      and interval.
    subscribe:
      summary: Receive presence events for a channel.
      operationId: receivePresence
      message:
        oneOf:
          - $ref: '#/components/messages/PresenceJoin'
          - $ref: '#/components/messages/PresenceLeave'
          - $ref: '#/components/messages/PresenceTimeout'
          - $ref: '#/components/messages/PresenceStateChange'
          - $ref: '#/components/messages/PresenceInterval'

  file:
    description: |
      File events delivered when a file is uploaded to a channel. Subscribers
      receive a file event containing the file ID, filename, and an optional
      description.
    subscribe:
      summary: Receive file events on a channel.
      operationId: receiveFile
      message:
        $ref: '#/components/messages/FileEvent'

  message-action:
    description: |
      Message action events delivered when a reaction or action (e.g. emoji
      reaction, read receipt) is added to or removed from a previously published
      message on a channel.
    subscribe:
      summary: Receive message action events on a channel.
      operationId: receiveMessageAction
      message:
        $ref: '#/components/messages/MessageActionEvent'

  app-context-events:
    description: |
      App Context (object metadata) events delivered when user, channel, or
      membership metadata is created, updated, or deleted. Event types are
      "set" or "delete"; entity types are "uuid", "channel", or "membership".
    subscribe:
      summary: Receive App Context (object) events.
      operationId: receiveAppContextEvent
      message:
        oneOf:
          - $ref: '#/components/messages/UuidMetadataEvent'
          - $ref: '#/components/messages/ChannelMetadataEvent'
          - $ref: '#/components/messages/MembershipEvent'

components:
  messages:
    Message:
      name: Message
      title: Published Message
      summary: A user-published message delivered to channel subscribers.
      contentType: application/json
      payload:
        $ref: '#/components/schemas/ListenerMessage'

    Signal:
      name: Signal
      title: Signal Event
      summary: A signal event delivered to channel subscribers (payload ≤ 64 bytes).
      contentType: application/json
      payload:
        $ref: '#/components/schemas/ListenerMessage'

    PresenceJoin:
      name: PresenceJoin
      title: Presence Join Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/PresenceJoinPayload'

    PresenceLeave:
      name: PresenceLeave
      title: Presence Leave Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/PresenceLeavePayload'

    PresenceTimeout:
      name: PresenceTimeout
      title: Presence Timeout Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/PresenceTimeoutPayload'

    PresenceStateChange:
      name: PresenceStateChange
      title: Presence State-Change Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/PresenceStateChangePayload'

    PresenceInterval:
      name: PresenceInterval
      title: Presence Interval Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/PresenceIntervalPayload'

    FileEvent:
      name: FileEvent
      title: File Upload Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/FileEventPayload'

    MessageActionEvent:
      name: MessageActionEvent
      title: Message Action Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/MessageActionEventPayload'

    UuidMetadataEvent:
      name: UuidMetadataEvent
      title: User (UUID) Metadata Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/AppContextEventPayload'

    ChannelMetadataEvent:
      name: ChannelMetadataEvent
      title: Channel Metadata Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/AppContextEventPayload'

    MembershipEvent:
      name: MembershipEvent
      title: Membership Event
      contentType: application/json
      payload:
        $ref: '#/components/schemas/AppContextEventPayload'

  schemas:
    Timetoken:
      type: string
      description: |
        17-digit PubNub timetoken — number of 100-nanosecond intervals since
        Unix epoch. Encoded as a string to preserve precision.
      pattern: '^[0-9]{17}$'
      example: '15610547826969050'

    ListenerMessage:
      type: object
      description: |
        SDK listener event object delivered for "message" and "signal" events.
        Fields as documented in the JavaScript SDK publish-and-subscribe API
        reference.
      properties:
        channel:
          type: string
          description: The channel ID for which the message belongs.
        subscription:
          type: [string, 'null']
          description: Channel group or wildcard subscription match, if any.
        timetoken:
          $ref: '#/components/schemas/Timetoken'
          description: Publish timetoken.
        message:
          description: The message payload (arbitrary JSON).
        publisher:
          type: string
          description: User ID of the message publisher.
        userMetadata:
          type: object
          description: Optional sender user metadata.
        meta:
          type: object
          description: Optional extra metadata published with the request.
      required:
        - channel
        - timetoken
        - message

    PresenceJoinPayload:
      type: object
      required:
        - action
        - channel
        - subscribedChannel
        - timetoken
        - occupancy
        - uuid
        - timestamp
      properties:
        action:
          type: string
          enum: [join]
        channel:
          type: string
        subscribedChannel:
          type: string
          description: Companion presence channel (suffix -pnpres).
        timetoken:
          $ref: '#/components/schemas/Timetoken'
        occupancy:
          type: integer
        uuid:
          type: string
        timestamp:
          type: integer
          description: Unix timestamp (seconds).
      example:
        action: join
        channel: chats.room1
        subscribedChannel: chats.room1-pnpres
        timetoken: '15119466699655811'
        occupancy: 2
        uuid: user123
        timestamp: 1511946669

    PresenceLeavePayload:
      type: object
      required:
        - action
        - channel
        - subscribedChannel
        - timetoken
        - occupancy
        - uuid
        - timestamp
      properties:
        action:
          type: string
          enum: [leave]
        channel:
          type: string
        subscribedChannel:
          type: string
        timetoken:
          $ref: '#/components/schemas/Timetoken'
        occupancy:
          type: integer
        uuid:
          type: string
        timestamp:
          type: integer
      example:
        action: leave
        channel: chats.room1
        subscribedChannel: chats.room1-pnpres
        timetoken: '15119466699655811'
        occupancy: 2
        uuid: user123
        timestamp: 1511946669

    PresenceTimeoutPayload:
      type: object
      required:
        - action
        - channel
        - subscribedChannel
        - timetoken
        - occupancy
        - uuid
        - timestamp
      properties:
        action:
          type: string
          enum: [timeout]
        channel:
          type: string
        subscribedChannel:
          type: string
        timetoken:
          $ref: '#/components/schemas/Timetoken'
        occupancy:
          type: integer
        uuid:
          type: string
        timestamp:
          type: integer
      example:
        action: timeout
        channel: chats.room1
        subscribedChannel: chats.room1-pnpres
        timetoken: '15119466699655811'
        occupancy: 2
        uuid: user123
        timestamp: 1511946669

    PresenceStateChangePayload:
      type: object
      required:
        - action
        - channel
        - subscribedChannel
        - state
        - timetoken
        - occupancy
        - uuid
        - timestamp
      properties:
        action:
          type: string
          enum: [state-change]
        channel:
          type: string
        subscription:
          type: [string, 'null']
        actualChannel:
          type: [string, 'null']
        subscribedChannel:
          type: string
        state:
          type: object
          description: Arbitrary JSON state object set by the user.
        timetoken:
          $ref: '#/components/schemas/Timetoken'
        occupancy:
          type: integer
        uuid:
          type: string
        timestamp:
          type: integer
      example:
        action: state-change
        channel: room-1
        subscription: null
        actualChannel: null
        subscribedChannel: room-1-pnpres
        state:
          mood: grumpy
        timetoken: '15119477895378127'
        occupancy: 5
        uuid: user1
        timestamp: 1511947789

    PresenceIntervalPayload:
      type: object
      description: |
        Interval event — replaces individual join/leave/timeout events when channel
        occupancy exceeds the "Announce Max" threshold. With Presence Deltas
        enabled the event also includes join/leave/timeout arrays of UUIDs that
        changed since the last interval.
      required:
        - action
        - channel
        - occupancy
        - subscribedChannel
        - timestamp
        - timetoken
      properties:
        action:
          type: string
          enum: [interval]
        channel:
          type: string
        occupancy:
          type: integer
        join:
          type: array
          items:
            type: string
          description: UUIDs that joined since the last interval (Presence Deltas).
        leave:
          type: array
          items:
            type: string
          description: UUIDs that left since the last interval (Presence Deltas).
        timeout:
          type: array
          items:
            type: string
          description: UUIDs that timed out since the last interval (Presence Deltas).
        subscribedChannel:
          type: string
        timestamp:
          type: integer
        timetoken:
          $ref: '#/components/schemas/Timetoken'
        hereNowRefresh:
          type: boolean
          description: |
            Flag indicating payload size exceeded limits; clients should use the
            Here Now API to retrieve active User IDs.
      example:
        action: interval
        channel: chats.megachat
        occupancy: 27
        join: [user123, user88]
        leave: [user20, user11, user14]
        timeout: [user42]
        subscribedChannel: chats.megachat-pnpres
        timestamp: 1511947739
        timetoken: '15119477396210903'
        hereNowRefresh: false

    FileEventPayload:
      type: object
      description: |
        File event delivered to subscribers when a file is uploaded to a channel.
        Contains the publishing channel, an optional message description, and
        the file descriptor (id, name). A download URL can be constructed using
        the SDK's getFileUrl() method.
      properties:
        channel:
          type: string
        subscription:
          type: [string, 'null']
        timetoken:
          $ref: '#/components/schemas/Timetoken'
        publisher:
          type: string
        message:
          description: Optional description published with the file.
        file:
          type: object
          required:
            - id
            - name
          properties:
            id:
              type: string
              description: Unique file identifier.
            name:
              type: string
              description: Filename.
      required:
        - channel
        - file

    MessageActionEventPayload:
      type: object
      description: |
        Message action event payload as documented in the addMessageAction /
        removeMessageAction API reference. Delivered via subscribe listeners to
        clients subscribed to the channel.
      properties:
        channel:
          type: string
        subscription:
          type: [string, 'null']
        timetoken:
          $ref: '#/components/schemas/Timetoken'
        publisher:
          type: string
        data:
          type: object
          properties:
            type:
              type: string
              description: Action type (e.g. "reaction", "receipt").
            value:
              type: string
              description: Action value (e.g. an emoji name).
            uuid:
              type: string
              description: User ID that added the action.
            actionTimetoken:
              $ref: '#/components/schemas/Timetoken'
            messageTimetoken:
              $ref: '#/components/schemas/Timetoken'
      example:
        data:
          type: reaction
          value: smiley_face
          uuid: user-456
          actionTimetoken: '15610547826970050'
          messageTimetoken: '15610547826969050'

    AppContextEventPayload:
      type: object
      description: |
        App Context (object metadata) event envelope. Delivered via subscribe
        when user, channel, or membership metadata is created, updated, or
        deleted. Structure as documented at
        https://www.pubnub.com/docs/general/metadata/basics.
      required:
        - channel
        - message
        - timetoken
      properties:
        channel:
          type: string
        subscription:
          type: [string, 'null']
        timetoken:
          $ref: '#/components/schemas/Timetoken'
        message:
          type: object
          required:
            - source
            - version
            - event
            - type
          properties:
            source:
              type: string
              enum: [objects]
            version:
              type: string
              example: '2.0'
            event:
              type: string
              enum: [set, delete]
              description: Operation that occurred.
            type:
              type: string
              enum: [uuid, channel, membership]
              description: Entity type the event refers to.
            data:
              type: object
              description: Event-specific entity payload.
      example:
        channel: sample-channel
        message:
          source: objects
          version: '2.0'
          event: set
          type: uuid
          data: {}
        subscription: sample-subscription
        timetoken: '15610547826969050'