Add functional SSE gateway with keep-alive streaming

apps/sse-gateway/README.md

@@ -0,0 +1,19 @@
+# SSE Gateway (functional stream)
+
+## Run
+
+```bash
+npm i express
+node apps/sse-gateway/server.mjs
+```
+
+## Test
+
+```bash
+curl -N "http://localhost:5000/sse?q=email"
+```
+
+You should receive:
+- `status` event
+- `result` event
+- periodic keep-alive comments (`: keep-alive`)

apps/sse-gateway/server.mjs

@@ -0,0 +1,62 @@
+import express from "express";
+
+const app = express();
+const PORT = Number(process.env.PORT) || 5000;
+
+app.get("/", (_req, res) => {
+  res.json({ ok: true, service: "sse-gateway" });
+});
+
+function detectIntent(q = "") {
+  const s = String(q).toLowerCase();
+
+  if (s.includes("email")) return ["email", ["Gmail"]];
+  if (s.includes("docs")) return ["docs", ["Google Docs"]];
+  if (s.includes("storage")) return ["storage", ["Google Drive"]];
+  if (s.includes("dev")) return ["dev", ["Replit", "Vercel"]];
+  if (s.includes("payment")) return ["payment", ["PayPal"]];
+  if (s.includes("ai")) return ["ai", ["Hugging Face"]];
+
+  return ["general", ["General"]];
+}
+
+app.get("/sse", (req, res) => {
+  const q = String(req.query.q || "");
+  const [intent, tools] = detectIntent(q);
+
+  res.setHeader("Content-Type", "text/event-stream; charset=utf-8");
+  res.setHeader("Cache-Control", "no-cache");
+  res.setHeader("Connection", "keep-alive");
+
+  if (typeof res.flushHeaders === "function") {
+    res.flushHeaders();
+  }
+
+  res.write("event: status\n");
+  res.write(`data: ${JSON.stringify({ status: "processing" })}\n\n`);
+
+  const resultTimer = setTimeout(() => {
+    res.write("event: result\n");
+    res.write(
+      `data: ${JSON.stringify({
+        query: q,
+        intent,
+        tools,
+      })}\n\n`,
+    );
+  }, 300);
+
+  const heartbeat = setInterval(() => {
+    res.write(": keep-alive\n\n");
+  }, 15000);
+
+  req.on("close", () => {
+    clearTimeout(resultTimer);
+    clearInterval(heartbeat);
+    res.end();
+  });
+});
+
+app.listen(PORT, "0.0.0.0", () => {
+  console.log(`SSE server running on ${PORT}`);
+});

package.json

@@ -8,7 +8,8 @@
     "example": "examples"
   },
   "scripts": {
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "test": "echo \"Error: no test specified\" && exit 1",
+    "sse:gateway": "node apps/sse-gateway/server.mjs"
   },
   "repository": {
     "type": "git",
@@ -22,6 +23,7 @@
   },
   "homepage": "https://github.com/NguyenCuong1989/DAIOF-Framework#readme",
   "dependencies": {
-    "@playwright/test": "^1.56.1"
+    "@playwright/test": "^1.56.1",
+    "express": "^4.21.2"
   }
 }