Conduit is the streaming service layer of Sentry's Real-Time Delivery Platform. It provides a scalable and multi-tenant way to deliver real-time data streams to clients.

Conduit is built as a Rust workspace consisting of multiple services that work together to provide reliable, high-performance real-time data streaming:

• Gateway Service: Handles client connections and delivers real-time data streams via SSE
• Publish Service: Accepts data from upstream services and publishes it to the appropriate streams
• Broker: Shared library for Redis-based message brokering between services

graph LR
    P[Publisher] --> |POST /publish| PS[Publish<br/>Service]
    PS --> |XADD| R[("Broker<br/>(Redis Streams)")]
    R --> |XREAD| GW[Gateway<br/>Service]
    C[Client<br/>Browser] -.-> |GET /events| GW
    GW ==> |SSE| C[Client<br/>Browser]

style P fill:#e1f5fe
style PS fill:#81c784
style R fill:#ff8a65
style GW fill:#81c784
style C fill:#e1f5fe

This example shows how to publish a multi-part stream using the phase system:

The following fields are used in the PublishRequest message (see full proto definition):

• START: Initiates a new stream. Should be the first message in any stream.
• DELTA: Adds incremental data to an ongoing stream. Can have multiple DELTA messages.
• END: Completes the stream and signals clients to close their connection. Also triggers a short TTL on the stream data in the broker.
• ERROR: Indicates an error occurred during the stream. The stream does NOT automatically terminate.

The payload field contains your application data and is typically used with DELTA phases. If payload is provided for other phases, they will NOT be processed by the client. Conduit places no restriction on payload content beyond being a valid JSON-like structure in the form of a google/protobuf/struct.proto.

POST /publish/{org_id}/{channel_id}
Content-Type: application/x-protobuf

PublishRequest {
  channel_id: "97f58c19-ce38-4c6b-8a5b-47f3405691f0"
  message_id: "70a29bd8-e4b6-4875-a478-76ee24ff4ae9"
  phase: START
  sequence: 1
  payload: {}
}

POST /publish/{org_id}/{channel_id}
Content-Type: application/x-protobuf

PublishRequest {
  channel_id: "97f58c19-ce38-4c6b-8a5b-47f3405691f0"
  message_id: "1a1b8d8b-68c5-4bbd-bb45-09b4bb01e2af"
  phase: DELTA
  sequence: 2
  payload: {
    "value": "hello,",
  }
}

POST /publish/{org_id}/{channel_id}
Content-Type: application/x-protobuf

PublishRequest {
  channel_id: "97f58c19-ce38-4c6b-8a5b-47f3405691f0"
  message_id: "8a5b915d-d434-4f82-a892-584ff9866654"
  phase: DELTA
  sequence: 3
  payload: {
    "value": " world!",
  }
}

POST /publish/{org_id}/{channel_id}
Content-Type: application/x-protobuf

PublishRequest {
  channel_id: "97f58c19-ce38-4c6b-8a5b-47f3405691f0"
  message_id: "70a29bd8-e4b6-4875-a478-76ee24ff4ae9"
  phase: END
  sequence: 4
  payload: {}
}

Clients connect to the Gateway service at GET /events/{org_id}?token=...&channel_id=... and receive Server-Sent Events:

event: stream
data: {
  "event_type": "stream",
  "message_id": "...",
  "channel_id": "...",
  "sequence": 2,
  "phase": "PHASE_DELTA",
  "payload": {"value": "hello,"}
}

The Gateway converts protobuf messages to JSON and sends all fields except client_timestamp. However, the official client library only forwards payload data for DELTA phase messages to application code.

Consumers can connect at any time during the stream lifecycle. When connecting, the Gateway delivers recent messages from the stream, enabling late-joining clients to receive already-published content.

Note: Connection requires a valid JWT token. Once connected, the stream remains active even if the token expires. Streams are trimmed to a maximum length, so connecting significantly late may result in missing earlier messages.

For TypeScript/JavaScript applications, use the official client library.