AsyncAPI channel · Supabase
· Supabase Realtime API
realtime/{topic}
A Realtime channel identified by a topic string. Clients join a channel by sending a phx_join message with configuration for the desired features (postgres_changes, broadcast, presence). Multiple features can be configured on a single channel.
topic — The channel topic identifier. For Postgres Changes, this typically follows the pattern realtime:schema:table. For Broadcast and Presence, any unique string can be used.
Operations
publish
sendRealtimeMessages
Send messages to a channel
subscribe
receiveRealtimeMessages
Receive real-time messages from a channel
Messages
phx_join
Join a Realtime channel with feature configuration
Content-Type:
broadcast
Broadcast a message to channel clients
Content-Type:
presence
Start tracking client presence
Content-Type:
phx_leave
Leave a Realtime channel
Content-Type:
heartbeat
Client heartbeat to keep connection alive
Content-Type:
postgres_changes
Database change notification
Content-Type:
presence_state
Full presence state for the channel
Content-Type:
presence_diff
Incremental presence state change
Content-Type:
phx_reply
Server reply to client messages
Content-Type:
About AsyncAPI
The AsyncAPI specification describes event-driven APIs the way OpenAPI describes request/response APIs. A channel is the named pipe — a webhook URL, a Kafka topic, a WebSocket route, an MQTT subject — that producers and consumers publish or subscribe to. Each channel carries one or more messages with structured payloads, and an operation declares whether a given party sends or receives on that channel.
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