From 98962da74f5766ab64f6e8f0f0e007ae117c2c0d Mon Sep 17 00:00:00 2001
From: Yogesh Tejwani <yogirajtejwani@gmail.com>
Date: Fri, 19 Jun 2026 13:16:33 +0530
Subject: [PATCH] fix(ui): proxy WebSocket signaling upgrade so local web calls
 work (#425)
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1.34.0 replaced the next.config `/api/* -> BACKEND_URL` rewrite with the
Route Handler `api/v1/[...path]/route.ts`. Route Handlers proxy HTTP fine
(so `/api/v1/*` still 200s) but cannot upgrade WebSocket connections. The
removed *rewrite* used to carry the upgrade, so without it the signaling
socket (`/api/v1/ws/signaling/...`) has no proxy path and every local web
call dies before WebRTC negotiation — the symptom reported in #425. nginx
would proxy the upgrade but only runs in the `remote` compose profile, so
local OSS deployments have nothing to carry it.

Re-add a `beforeFiles` rewrite scoped to `/api/v1/ws/:path*` so the upgrade
is proxied to the backend *before* the `[...path]` Route Handler can swallow
it. HTTP `/api/v1/*` is untouched and still flows through the Route Handler
(auth/cookie handling intact).

Verified on a 1.34.0-derived source build: signaling WS now reports
`[accepted]` / `connection open` server-side and `WebSocket connected` +
`ICE connection state: connected` client-side; WebRTC negotiates end-to-end.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 ui/next.config.ts | 43 +++++++++++++++++++++++++++++--------------
 1 file changed, 29 insertions(+), 14 deletions(-)

diff --git a/ui/next.config.ts b/ui/next.config.ts
index 98242c20..48708c72 100644
--- a/ui/next.config.ts
+++ b/ui/next.config.ts
@@ -8,20 +8,35 @@ const nextConfig: NextConfig = {
     serverSourceMaps: true,
   },
   async rewrites() {
-    return [
-      {
-        source: "/ingest/static/:path*",
-        destination: "https://us-assets.i.posthog.com/static/:path*",
-      },
-      {
-        source: "/ingest/:path*",
-        destination: "https://us.i.posthog.com/:path*",
-      },
-      {
-        source: "/ingest/decide",
-        destination: "https://us.i.posthog.com/decide",
-      },
-    ];
+    return {
+      // beforeFiles runs before Next.js route handlers, so the WebSocket
+      // signaling path is proxied straight to the backend instead of being
+      // swallowed by api/v1/[...path]/route.ts — a Route Handler that proxies
+      // HTTP fine but CANNOT upgrade WebSocket connections. The pre-1.34.0
+      // /api proxy *rewrite* used to carry this upgrade; removing it broke all
+      // local web calls (dograh #425). Scoped to /ws/ so HTTP /api/v1 still
+      // flows through the route handler (auth/cookie handling intact).
+      beforeFiles: [
+        {
+          source: "/api/v1/ws/:path*",
+          destination: `${process.env.BACKEND_URL || 'http://localhost:8000'}/api/v1/ws/:path*`,
+        },
+      ],
+      afterFiles: [
+        {
+          source: "/ingest/static/:path*",
+          destination: "https://us-assets.i.posthog.com/static/:path*",
+        },
+        {
+          source: "/ingest/:path*",
+          destination: "https://us.i.posthog.com/:path*",
+        },
+        {
+          source: "/ingest/decide",
+          destination: "https://us.i.posthog.com/decide",
+        },
+      ],
+    };
   },
   // This is required to support PostHog trailing slash API requests
   skipTrailingSlashRedirect: true,