feat: link user feedback and diagram saves to chat traces in Langfuse

- Update log-feedback API to find existing chat trace by sessionId and attach score to it - Update log-save API to create span on existing chat trace instead of standalone trace - Add thumbs up/down feedback buttons on assistant messages - Add message regeneration and edit functionality - Add save dialog with format selection (drawio, png, svg) - Pass sessionId through components for Langfuse linking
2026-01-02 22:32:27 +08:00 · 2025-12-04 22:56:59 +09:00
parent 5f4d31e708
commit d8f2c85dab
11 changed files with 1484 additions and 97 deletions
--- a/app/api/log-feedback/route.ts
+++ b/app/api/log-feedback/route.ts
@@ -0,0 +1,95 @@
+import { LangfuseClient } from '@langfuse/client';
+import { randomUUID } from 'crypto';
+
+export async function POST(req: Request) {
+  // Check if Langfuse is configured
+  if (!process.env.LANGFUSE_PUBLIC_KEY || !process.env.LANGFUSE_SECRET_KEY) {
+    return Response.json({ success: true, logged: false });
+  }
+
+  const { messageId, feedback, sessionId } = await req.json();
+
+  // Get user IP for tracking
+  const forwardedFor = req.headers.get('x-forwarded-for');
+  const userId = forwardedFor?.split(',')[0]?.trim() || 'anonymous';
+
+  try {
+    // Create Langfuse client
+    const langfuse = new LangfuseClient({
+      publicKey: process.env.LANGFUSE_PUBLIC_KEY,
+      secretKey: process.env.LANGFUSE_SECRET_KEY,
+      baseUrl: process.env.LANGFUSE_BASEURL,
+    });
+
+    // Find the most recent chat trace for this session to attach the score to
+    const tracesResponse = await langfuse.api.trace.list({
+      sessionId,
+      limit: 1,
+    });
+
+    const traces = tracesResponse.data || [];
+    const latestTrace = traces[0];
+
+    if (!latestTrace) {
+      // No trace found for this session - create a standalone feedback trace
+      const traceId = randomUUID();
+      const timestamp = new Date().toISOString();
+
+      await langfuse.api.ingestion.batch({
+        batch: [
+          {
+            type: 'trace-create',
+            id: randomUUID(),
+            timestamp,
+            body: {
+              id: traceId,
+              name: 'user-feedback',
+              sessionId,
+              userId,
+              input: { messageId, feedback },
+              metadata: { source: 'feedback-button', note: 'standalone - no chat trace found' },
+              timestamp,
+            },
+          },
+          {
+            type: 'score-create',
+            id: randomUUID(),
+            timestamp,
+            body: {
+              id: randomUUID(),
+              traceId,
+              name: 'user-feedback',
+              value: feedback === 'good' ? 1 : 0,
+              comment: `User gave ${feedback} feedback`,
+            },
+          },
+        ],
+      });
+    } else {
+      // Attach score to the existing chat trace
+      const timestamp = new Date().toISOString();
+
+      await langfuse.api.ingestion.batch({
+        batch: [
+          {
+            type: 'score-create',
+            id: randomUUID(),
+            timestamp,
+            body: {
+              id: randomUUID(),
+              traceId: latestTrace.id,
+              name: 'user-feedback',
+              value: feedback === 'good' ? 1 : 0,
+              comment: `User gave ${feedback} feedback`,
+            },
+          },
+        ],
+      });
+    }
+
+    return Response.json({ success: true, logged: true });
+  } catch (error) {
+    console.error('Langfuse feedback error:', error);
+    return Response.json({ success: false, error: String(error) }, { status: 500 });
+  }
+}