ProtocolSseTransportOptions

Retries and concurrency for SSE/command HTTP. When omitted, requests use raw fetch with no automatic retries (same as constructing ProtocolSseTransportAdapter without this option).

Headers applied to every request.

The configured API key, when present, is added as the x-api-key header after these defaults are initialized.

Optional fetch override, forwarded to the SSE transport. Useful for auth proxies, Next.js route handlers, or tests with injected mocks. Ignored when webSocketFactory is also supplied.

Idle-reconnect policy guarding against half-open sockets that hang indefinitely with no error or close (e.g. a platform revision rollover that hard-kills the serving pod). On idle the underlying read is aborted, which the reconnect loop treats like any other disconnect, re-subscribing with since from the last seen sequence.

• "auto": arm only once the server's SSE keep-alive heartbeats (LangGraph Platform: : heartbeat every ~5s) are observed, sizing the window from their cadence. Independent of agent activity; stays dormant on heartbeat-less servers.
• a number: a fixed idle window in milliseconds.
• 0: disables it.

Maximum reconnect attempts after an unexpected SSE disconnect. Defaults to 5. Set to 0 to disable automatic reconnection.

Called before each SSE reconnect attempt (after backoff delay).

Hook for inspecting or mutating a request before it is sent.

Receives the resolved URL and prepared RequestInit; return the original init or a replacement object to continue the request.

Override the default /threads/:threadId/... protocol paths.

Backoff before each SSE reconnect attempt. Defaults to webSocketReconnectDelayMs from ./websocket.js.

Thread ID this transport currently targets.