Method send

backend/src/workflows/workflows.controller.ts:896–916

(event: string, payload: unknown)

    let latestEventTimestamp: number | null = null;

    const send = (event: string, payload: unknown) => {
      if (!active) {
        return;
      }
      try {
        res.write(`event: ${event}\n`);
        res.write(`data: ${JSON.stringify(payload)}\n\n`);
        // Flush headers if available (helps with immediate delivery)
        if (typeof (res as any).flush === 'function') {
          (res as any).flush();
        }
      } catch (error) {
        // Connection closed or error writing
        console.warn(`Failed to send SSE event ${event}:`, error);
        if (!active) {
          return;
        }
        active = false;
        void cleanup();
      }
    };

    const cleanup = async () => {
      if (!active) {