Realtime Channel

{
  "$id": "realtime-channel.json",
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "title": "Realtime Channel",
  "description": "A canonical representation of a realtime channel — the named topic, room, queue, or stage to which clients publish and from which they subscribe. Generalizes the channel concepts found in Ably, Pusher, PubNub, Socket.IO rooms/namespaces, MQTT topics, Phoenix Channels, GraphQL subscription topics, and LiveKit rooms.",
  "type": "object",
  "required": [
    "id",
    "name",
    "protocol"
  ],
  "properties": {
    "id": {
      "type": "string",
      "description": "A globally unique identifier for the channel within a provider tenant — typically a UUID, an opaque token, or a provider-scoped string."
    },
    "name": {
      "type": "string",
      "description": "The human-readable channel name as it appears in client subscribe/publish calls (e.g., 'chat:room-42', 'orders/123/events', 'sensors/+/temperature').",
      "maxLength": 1024
    },
    "namespace": {
      "type": "string",
      "description": "Optional namespace or scope grouping multiple channels (e.g., an Ably namespace prefix, a Socket.IO namespace, a tenant identifier)."
    },
    "protocol": {
      "type": "string",
      "description": "The underlying realtime protocol carrying messages on this channel.",
      "enum": [
        "websocket",
        "sse",
        "webrtc",
        "mqtt",
        "coap",
        "grpc",
        "graphql-ws",
        "graphql-sse",
        "webtransport",
        "http-long-poll",
        "proprietary"
      ]
    },
    "provider": {
      "type": "string",
      "description": "Identifier for the realtime provider or platform hosting the channel (e.g., 'ably', 'pubnub', 'pusher', 'livekit', 'socket.io', 'mqtt-broker')."
    },
    "type": {
      "type": "string",
      "description": "The functional role of the channel.",
      "enum": [
        "pub-sub",
        "chat",
        "presence",
        "signaling",
        "data",
        "media",
        "notifications",
        "broadcast",
        "request-response"
      ]
    },
    "mode": {
      "type": "string",
      "description": "Directionality of the channel.",
      "enum": [
        "bidirectional",
        "server-to-client",
        "client-to-server",
        "peer-to-peer"
      ]
    },
    "qualityOfService": {
      "type": "string",
      "description": "Delivery guarantee for messages on the channel, modeled on MQTT QoS plus the common at-least-once/exactly-once labels.",
      "enum": [
        "at-most-once",
        "at-least-once",
        "exactly-once"
      ]
    },
    "ordering": {
      "type": "string",
      "description": "Per-channel ordering guarantee.",
      "enum": [
        "fifo",
        "per-publisher",
        "none"
      ]
    },
    "persistence": {
      "type": "object",
      "description": "Whether and how messages published to this channel are retained for replay or history.",
      "properties": {
        "enabled": {
          "type": "boolean",
          "description": "True if message history is retained."
        },
        "retention": {
          "type": "string",
          "description": "Retention period expressed as an ISO 8601 duration (e.g., 'PT24H', 'P7D')."
        },
        "maxMessages": {
          "type": "integer",
          "description": "Maximum number of messages retained, if bounded by count rather than time.",
          "minimum": 0
        }
      },
      "additionalProperties": false
    },
    "presence": {
      "type": "object",
      "description": "Presence/membership characteristics of the channel.",
      "properties": {
        "enabled": {
          "type": "boolean",
          "description": "True if the channel tracks present members."
        },
        "memberCount": {
          "type": "integer",
          "description": "Current number of present members, when known.",
          "minimum": 0
        }
      },
      "additionalProperties": false
    },
    "access": {
      "type": "object",
      "description": "Access control posture for the channel.",
      "properties": {
        "scope": {
          "type": "string",
          "description": "Visibility scope.",
          "enum": [
            "public",
            "private",
            "presence",
            "encrypted"
          ]
        },
        "authMethod": {
          "type": "string",
          "description": "How clients authenticate to subscribe/publish.",
          "enum": [
            "api-key",
            "jwt",
            "token-request",
            "oauth2",
            "mtls",
            "anonymous"
          ]
        },
        "capabilities": {
          "type": "array",
          "description": "Granted capabilities on this channel (e.g., 'subscribe', 'publish', 'presence', 'history').",
          "items": {
            "type": "string"
          }
        }
      },
      "additionalProperties": false
    },
    "encryption": {
      "type": "object",
      "description": "End-to-end or in-flight encryption applied to messages on the channel.",
      "properties": {
        "inFlight": {
          "type": "boolean",
          "description": "True when transport-level encryption (TLS/DTLS/SRTP) is in use."
        },
        "endToEnd": {
          "type": "boolean",
          "description": "True when payload-level encryption is applied above the transport."
        },
        "algorithm": {
          "type": "string",
          "description": "Encryption algorithm (e.g., 'AES-256-GCM')."
        }
      },
      "additionalProperties": false
    },
    "createdAt": {
      "type": "string",
      "format": "date-time",
      "description": "When the channel was created."
    },
    "labels": {
      "type": "object",
      "description": "Free-form key/value labels for tenancy, environment, application, etc.",
      "additionalProperties": {
        "type": "string"
      }
    }
  },
  "additionalProperties": false
}