/v3/sync
Long-polling sync channel. A client opens an authenticated HTTPS GET request to `/_matrix/client/v3/sync` with a `since` token and an optional `timeout` (milliseconds). The homeserver holds the connection open until at least one event is available for the client or until the timeout is reached, then responds with a JSON SyncResponse. The `next_batch` value is supplied as `since` on the subsequent
Channel address
Parameters
timeout— Maximum time in milliseconds for the server to wait for events before responding. Default 0 (return immediately). Long-polling clients typically use 30000 ms.since— Pagination token from a previous sync's `next_batch`. Omit on the initial sync to receive a snapshot.filter— Filter ID returned by `POST /v3/user/{userId}/filter`, or an inline JSON-encoded Filter object that limits which events the server returns.full_state— If true, all state events known to the server are returned even if `since` is non-empty. Default false.set_presence— Presence state to set for the calling user for the duration of the request. One of `offline`, `online`, or `unavailable`. Default `online`.use_state_after— If true, the server returns room state at the END of the timeline (as `state_after`) rather than at the start (as `state`). Default false. Added in a recent client-server spec version.
Operations
Messages
application/jsonAbout 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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