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fix: SSE stream endpoint with proper HTTP/2 stream handling and heartbeat

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- Fixed /api/stream/requests endpoint HTTP/2 INTERNAL_ERROR
- Use reply.raw.writeHead() instead of Fastify headers API for SSE
- Added 30s heartbeat to keep connection alive
- Proper event format with 'event:' and 'data:' fields
- Comprehensive error handling and cleanup on disconnect
- Mirrors working pattern from /api/stream/costs endpoint
- Resolves dashboard perpetual 'Loading...' state
This commit is contained in:
Rene Fichtmueller 2026-04-26 23:52:13 +02:00
parent 200cc7f2dc
commit 91384dbb2a
1 changed files with 60 additions and 9 deletions
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67
packages/gateway/src/routes/dashboard.ts
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@ -463,31 +463,82 @@ export async function dashboardRoute(fastify: FastifyInstance): Promise<void> {
// Server-Sent Events endpoint for real-time request updates
fastify.get('/api/stream/requests', async (request: FastifyRequest, reply: FastifyReply) => {
// Set SSE headers
reply.type('text/event-stream');
reply.header('Cache-Control', 'no-cache');
reply.header('Connection', 'keep-alive');
// Use raw Node.js API to properly initialize HTTP/2 stream
reply.raw.writeHead(200, {
'Content-Type': 'text/event-stream',
'Cache-Control': 'no-cache',
'Connection': 'keep-alive',
'Access-Control-Allow-Origin': '*',
'Access-Control-Allow-Methods': 'GET',
'Access-Control-Allow-Headers': 'Content-Type',
});
const clientIp = request.ip;
const clientId = `${clientIp}-${Date.now()}`;
logger.info({ clientId, clientIp, activeListeners: globalRequestStream.getListenerCount() }, 'SSE client connected to /api/stream/requests');
// Send initial connection message
reply.raw.write(`data: ${JSON.stringify({ type: 'connected', timestamp: new Date().toISOString() })}\n\n`);
reply.raw.write('event: connected\n');
reply.raw.write(`data: ${JSON.stringify({ clientId, timestamp: new Date().toISOString() })}\n\n`);
// Subscribe to request events
const unsubscribe = globalRequestStream.onRequest((event) => {
try {
reply.raw.write('event: request-update\n');
reply.raw.write(`data: ${JSON.stringify(event)}\n\n`);
} catch (err) {
logger.debug({ clientId, err }, 'Error writing to SSE stream /api/stream/requests');
unsubscribe();
if (!reply.raw.writableEnded) {
reply.raw.end();
}
}
});
// Keep connection alive with heartbeat every 30 seconds
const heartbeat = setInterval(() => {
try {
if (reply.raw.writable) {
reply.raw.write(': heartbeat\n\n');
} else {
clearInterval(heartbeat);
unsubscribe();
}
} catch (err) {
logger.debug({ clientId, err }, 'Heartbeat failed on /api/stream/requests');
clearInterval(heartbeat);
unsubscribe();
}
}, 30000);
// Handle client disconnect
reply.raw.on('close', () => {
logger.info({ clientId }, 'SSE client disconnected from /api/stream/requests');
clearInterval(heartbeat);
unsubscribe();
logger.info('SSE client disconnected from /api/stream/requests');
});
// Handle stream errors
reply.raw.on('error', (error) => {
logger.error({ error }, 'SSE stream error');
logger.error({ clientId, error }, 'SSE stream error on /api/stream/requests');
clearInterval(heartbeat);
unsubscribe();
});
logger.info(`SSE client connected to /api/stream/requests (active: ${globalRequestStream.getListenerCount()})`);
// Cleanup on reply finish
reply.raw.on('finish', () => {
logger.debug({ clientId }, 'SSE stream finished on /api/stream/requests');
clearInterval(heartbeat);
unsubscribe();
});
// Prevent response from ending automatically
request.raw.on('close', () => {
logger.debug({ clientId }, 'Request closed on /api/stream/requests');
clearInterval(heartbeat);
unsubscribe();
});
});
// Test endpoint