Refactor SSE to use Hono's built-in streamSSE

Author: chriswritescode-dev

backend/src/routes/sse.ts

@@ -1,5 +1,5 @@
 import { Hono } from 'hono'
-import { stream } from 'hono/streaming'
+import { streamSSE } from 'hono/streaming'
 import { sseAggregator } from '../services/sse-aggregator'
 import { SSESubscribeSchema } from '@opencode-manager/shared/schemas'
 import { logger } from '../utils/logger'
@@ -15,45 +15,32 @@ export function createSSERoutes() {
     const directories = directoriesParam ? directoriesParam.split(',').filter(Boolean) : []
     const clientId = `client_${Date.now()}_${Math.random().toString(36).slice(2)}`
 
-    c.header('Content-Type', 'text/event-stream')
-    c.header('Cache-Control', 'no-cache, no-store, no-transform')
-    c.header('Connection', 'keep-alive')
     c.header('X-Accel-Buffering', 'no')
 
-    return stream(c, async (writer) => {
-      const encoder = new TextEncoder()
-      const writeSSE = (event: string, data: string) => {
-        const lines = []
-        if (event) lines.push(`event: ${event}`)
-        lines.push(`data: ${data}`)
-        lines.push('')
-        lines.push('')
-        writer.write(encoder.encode(lines.join('\n')))
-      }
-
+    return streamSSE(c, async (stream) => {
       const cleanup = sseAggregator.addClient(
         clientId,
-        (event, data) => {
-          writeSSE(event, data)
+        async (event, data) => {
+          await stream.writeSSE({ event, data })
         },
         directories
       )
 
-      const heartbeatInterval = setInterval(() => {
+      const heartbeatInterval = setInterval(async () => {
         try {
-          writeSSE('heartbeat', JSON.stringify({ timestamp: Date.now() }))
+          await stream.writeSSE({ event: 'heartbeat', data: JSON.stringify({ timestamp: Date.now() }) })
         } catch {
           clearInterval(heartbeatInterval)
         }
       }, HEARTBEAT_INTERVAL_MS)
 
-      writer.onAbort(() => {
+      stream.onAbort(() => {
         clearInterval(heartbeatInterval)
         cleanup()
       })
 
       try {
-        writeSSE('connected', JSON.stringify({ clientId, directories, ...sseAggregator.getConnectionStatus() }))
+        await stream.writeSSE({ event: 'connected', data: JSON.stringify({ clientId, directories, ...sseAggregator.getConnectionStatus() }) })
       } catch (err) {
         logger.error(`Failed to send SSE connected event for ${clientId}:`, err)
       }