Open a signed Server-Sent Events stream

Available for: Concierge API, Enterprise API.

Open the signed streamUrl returned by subscription creation to receive named SSE events containing JSON data and comment keep-alives. No X-Api-Key header is needed for this GET. Reconnect with the last successfully applied data-event ID in Last-Event-ID. Recent updates may be recovered on reconnect, but recovery is best effort; reload current state through REST after a gap or whenever continuity is uncertain.

Real-time market data is available through Concierge API and Enterprise API. Free API does not include streaming.

Use data.streamUrl returned by POST /subscriptions as-is. No API-key header is needed. Do not construct or modify the signed token. Successful responses are a long-lived text/event-stream, not a JSON response envelope. Parse SSE event names and JSON data, ignore comment keep-alives, and reconnect with the last successfully applied data-event ID in Last-Event-ID. Resume is best effort from a bounded buffer on the same API instance, not a historical replay service. A gap event means the client must reload a REST snapshot. Revoked credentials may close an open stream; create a new subscription when the token expires.