fix: add POST handler to /api/rag for semantic search + agent proxy

- Added POST handler that proxies retrieve/agent/tags actions to RAG API
- Maps RAG API response shape (chunks[].rerank_score) to frontend expected format
- Normalizes rerank_score (0-10 range) to 0-1 score for display
- Disabled tags fetch on mount (blocks RAG API - scrolls all 49k Qdrant points)

src/app/api/rag/route.ts

@@ -1,7 +1,8 @@
-import { NextResponse } from "next/server";
+import { NextRequest, NextResponse } from "next/server";
 
 const RAG_API = process.env.RAG_API_URL || "http://localhost:8099";
 
+/* ─── GET /api/rag  →  status + ingest-progress ─── */
 export async function GET() {
   try {
     const [statusRes, progressRes] = await Promise.all([
@@ -32,3 +33,95 @@ export async function GET() {
     );
   }
 }
+
+/* ─── POST /api/rag  →  proxy retrieve / agent / tags ─── */
+export async function POST(req: NextRequest) {
+  try {
+    const body = await req.json();
+    const { action, ...params } = body;
+
+    /* --- tags --------------------------------------------------------- */
+    if (action === "tags") {
+      const res = await fetch(`${RAG_API}/tags`, {
+        next: { revalidate: 0 },
+      });
+      const data = await res.json();
+      // normalise → always return { tags: string[] }
+      const tags: string[] = Array.isArray(data)
+        ? data
+        : Array.isArray(data.tags)
+        ? data.tags
+        : [];
+      return NextResponse.json({ tags });
+    }
+
+    /* --- retrieve (semantic search) ----------------------------------- */
+    if (action === "retrieve") {
+      const res = await fetch(`${RAG_API}/retrieve`, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          question: params.question,
+          top_k: params.top_k ?? 8,
+          tags: params.tags,
+        }),
+      });
+
+      if (!res.ok) {
+        const err = await res.text();
+        return NextResponse.json(
+          { error: err || "RAG retrieve failed" },
+          { status: res.status }
+        );
+      }
+
+      const data = await res.json();
+
+      // RAG API returns { chunks: [...] } — map to frontend's expected shape
+      const chunks = data.chunks ?? data.results ?? (Array.isArray(data) ? data : []);
+      const results = chunks.map((c: Record<string, unknown>) => ({
+        title: c.title ?? "",
+        text: c.text ?? "",
+        source: c.source_path ?? c.source ?? "",
+        page: c.page ?? null,
+        score: c.rerank_score != null
+          ? Math.min((c.rerank_score as number) / 10, 1)   // normalise rerank_score ≈0-10 → 0-1
+          : c.score ?? null,
+        tags: c.tags ?? [],
+      }));
+
+      return NextResponse.json(results);
+    }
+
+    /* --- agent --------------------------------------------------------- */
+    if (action === "agent") {
+      const res = await fetch(`${RAG_API}/agent`, {
+        method: "POST",
+        headers: { "Content-Type": "application/json" },
+        body: JSON.stringify({
+          question: params.question,
+          max_steps: params.max_steps ?? 5,
+        }),
+      });
+
+      if (!res.ok) {
+        const err = await res.text();
+        return NextResponse.json(
+          { error: err || "RAG agent failed" },
+          { status: res.status }
+        );
+      }
+
+      const data = await res.json();
+      return NextResponse.json(data);
+    }
+
+    return NextResponse.json(
+      { error: `Unknown action: ${action}` },
+      { status: 400 }
+    );
+  } catch (err) {
+    const message = err instanceof Error ? err.message : "Unexpected error";
+    return NextResponse.json({ error: message }, { status: 500 });
+  }
+}

src/components/SemanticSearch.tsx

@@ -232,20 +232,20 @@ export default function SemanticSearch() {
   const [agentResult, setAgentResult] = useState<AgentResponse | null>(null);
 
   // fetch tags on mount
-  useEffect(() => {
+//   useEffect(() => {
-    ragFetch({ action: "tags" })
+//     ragFetch({ action: "tags" })
-      .then((data) => {
+//       .then((data) => {
-        const tags: string[] = Array.isArray(data)
+//         const tags: string[] = Array.isArray(data)
-          ? data
+//           ? data
-          : Array.isArray(data.tags)
+//           : Array.isArray(data.tags)
-          ? data.tags
+//           ? data.tags
-          : [];
+//           : [];
-        setAvailableTags(tags);
+//         setAvailableTags(tags);
-      })
+//       })
-      .catch(() => {
+//       .catch(() => {
-        /* silently ignore – tags are optional */
+//         /* silently ignore – tags are optional */
-      });
+//       });
-  }, []);
+//   }, []);
 
   const toggleTag = useCallback((tag: string) => {
     setSelectedTags((prev) =>