function setHeaders(req, res, next) { // Skip SSE headers for resumable mode - it returns JSON first, then client subscribes separately if (req.query.resumable === 'true') { return next(); } res.writeHead(200, { Connection: 'keep-alive', 'Content-Type': 'text/event-stream', 'Cache-Control': 'no-cache, no-transform', 'Access-Control-Allow-Origin': '*', 'X-Accel-Buffering': 'no', }); next(); } module.exports = setHeaders;