diff --git a/backend/src/__tests__/integration/chat.routes.test.ts b/backend/src/__tests__/integration/chat.routes.test.ts
index 64e71ecd..8f967663 100644
--- a/backend/src/__tests__/integration/chat.routes.test.ts
+++ b/backend/src/__tests__/integration/chat.routes.test.ts
@@ -41,7 +41,6 @@ function mockSupabase() {
 
 vi.mock("../../lib/supabase", () => ({
     createServerSupabase: vi.fn(() => mockSupabase()),
-    getUserIdFromRequest: vi.fn(async () => "u1"),
 }));
 
 // Authenticate every request as user "u1" without exercising the real Supabase
diff --git a/backend/src/__tests__/integration/documentsUpload.routes.test.ts b/backend/src/__tests__/integration/documentsUpload.routes.test.ts
index e7544cfb..faca4ab0 100644
--- a/backend/src/__tests__/integration/documentsUpload.routes.test.ts
+++ b/backend/src/__tests__/integration/documentsUpload.routes.test.ts
@@ -25,7 +25,6 @@ function mockSupabase() {
 
 vi.mock("../../lib/supabase", () => ({
     createServerSupabase: vi.fn(() => mockSupabase()),
-    getUserIdFromRequest: vi.fn(async () => "u1"),
 }));
 
 vi.mock("../../middleware/auth", () => ({
diff --git a/backend/src/__tests__/integration/projectChat.routes.test.ts b/backend/src/__tests__/integration/projectChat.routes.test.ts
index 8f6af783..e2fbd5e3 100644
--- a/backend/src/__tests__/integration/projectChat.routes.test.ts
+++ b/backend/src/__tests__/integration/projectChat.routes.test.ts
@@ -38,7 +38,6 @@ function mockSupabase() {
 
 vi.mock("../../lib/supabase", () => ({
     createServerSupabase: vi.fn(() => mockSupabase()),
-    getUserIdFromRequest: vi.fn(async () => "u1"),
 }));
 
 vi.mock("../../middleware/auth", () => ({
diff --git a/backend/src/__tests__/integration/projects.routes.test.ts b/backend/src/__tests__/integration/projects.routes.test.ts
index 408f24e2..d54eead2 100644
--- a/backend/src/__tests__/integration/projects.routes.test.ts
+++ b/backend/src/__tests__/integration/projects.routes.test.ts
@@ -68,7 +68,6 @@ function mockSupabase() {
 
 vi.mock("../../lib/supabase", () => ({
     createServerSupabase: vi.fn(() => mockSupabase()),
-    getUserIdFromRequest: vi.fn(async () => "u1"),
 }));
 
 vi.mock("../../middleware/auth", () => ({
diff --git a/backend/src/__tests__/integration/tabular.routes.test.ts b/backend/src/__tests__/integration/tabular.routes.test.ts
index c828148c..6ee9db10 100644
--- a/backend/src/__tests__/integration/tabular.routes.test.ts
+++ b/backend/src/__tests__/integration/tabular.routes.test.ts
@@ -81,7 +81,6 @@ function mockSupabase() {
 
 vi.mock("../../lib/supabase", () => ({
     createServerSupabase: vi.fn(() => mockSupabase()),
-    getUserIdFromRequest: vi.fn(async () => "u1"),
 }));
 
 vi.mock("../../middleware/auth", () => ({
diff --git a/backend/src/__tests__/integration/user.routes.test.ts b/backend/src/__tests__/integration/user.routes.test.ts
index d47b5bb5..2e043297 100644
--- a/backend/src/__tests__/integration/user.routes.test.ts
+++ b/backend/src/__tests__/integration/user.routes.test.ts
@@ -106,7 +106,6 @@ function mockSupabase() {
 
 vi.mock("../../lib/supabase", () => ({
     createServerSupabase: vi.fn(() => mockSupabase()),
-    getUserIdFromRequest: vi.fn(async () => "u1"),
 }));
 
 // requireAuth always authenticates u1. requireMfaIfEnrolled is a reconfigurable
diff --git a/backend/src/lib/supabase.ts b/backend/src/lib/supabase.ts
index da821862..51ad41ed 100644
--- a/backend/src/lib/supabase.ts
+++ b/backend/src/lib/supabase.ts
@@ -12,33 +12,3 @@ export function createServerSupabase() {
   }
   return createClient(url, key, { auth: { persistSession: false } });
 }
-
-/**
- * Extract and verify the Supabase JWT from the Authorization header.
- * Returns the user's UUID string, or throws a Response with 401.
- */
-export async function getUserIdFromRequest(req: Request): Promise<string> {
-  const auth = req.headers.get("authorization") ?? "";
-  if (!auth.startsWith("Bearer ")) {
-    throw new Response("Missing or invalid Authorization header", {
-      status: 401,
-    });
-  }
-  const token = auth.slice(7).trim();
-
-  const supabaseUrl = process.env.SUPABASE_URL || "";
-  const serviceKey = process.env.SUPABASE_SECRET_KEY || "";
-
-  if (!supabaseUrl || !serviceKey) {
-    throw new Response("Server auth is not configured", { status: 500 });
-  }
-
-  const admin = createClient(supabaseUrl, serviceKey, {
-    auth: { persistSession: false },
-  });
-  const { data } = await admin.auth.getUser(token);
-  if (!data.user) {
-    throw new Response("Invalid or expired token", { status: 401 });
-  }
-  return data.user.id;
-}