From 8979fc5f6a2d745f2251e48ecbfe41104a29e936 Mon Sep 17 00:00:00 2001
From: Gaurav <39389231+gsquared94@users.noreply.github.com>
Date: Sun, 15 Feb 2026 19:20:22 -0800
Subject: [PATCH] fix(core): propagate User-Agent header to setup-phase
 CodeAssist API calls (#19182)

---
 .../core/src/code_assist/codeAssist.test.ts   |  2 ++
 packages/core/src/code_assist/codeAssist.ts   |  6 +++++-
 packages/core/src/code_assist/setup.test.ts   | 21 +++++++++++++++++++
 packages/core/src/code_assist/setup.ts        |  4 +++-
 4 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/packages/core/src/code_assist/codeAssist.test.ts b/packages/core/src/code_assist/codeAssist.test.ts
index fb48c3abf6..0e24f51feb 100644
--- a/packages/core/src/code_assist/codeAssist.test.ts
+++ b/packages/core/src/code_assist/codeAssist.test.ts
@@ -64,6 +64,7 @@ describe('codeAssist', () => {
       expect(setupUser).toHaveBeenCalledWith(
         mockAuthClient,
         mockValidationHandler,
+        httpOptions,
       );
       expect(MockedCodeAssistServer).toHaveBeenCalledWith(
         mockAuthClient,
@@ -93,6 +94,7 @@ describe('codeAssist', () => {
       expect(setupUser).toHaveBeenCalledWith(
         mockAuthClient,
         mockValidationHandler,
+        httpOptions,
       );
       expect(MockedCodeAssistServer).toHaveBeenCalledWith(
         mockAuthClient,
diff --git a/packages/core/src/code_assist/codeAssist.ts b/packages/core/src/code_assist/codeAssist.ts
index 3b87cb03e2..5d41b28c24 100644
--- a/packages/core/src/code_assist/codeAssist.ts
+++ b/packages/core/src/code_assist/codeAssist.ts
@@ -24,7 +24,11 @@ export async function createCodeAssistContentGenerator(
     authType === AuthType.COMPUTE_ADC
   ) {
     const authClient = await getOauthClient(authType, config);
-    const userData = await setupUser(authClient, config.getValidationHandler());
+    const userData = await setupUser(
+      authClient,
+      config.getValidationHandler(),
+      httpOptions,
+    );
     return new CodeAssistServer(
       authClient,
       userData.projectId,
diff --git a/packages/core/src/code_assist/setup.test.ts b/packages/core/src/code_assist/setup.test.ts
index e1c43ef6e6..e4418aeca2 100644
--- a/packages/core/src/code_assist/setup.test.ts
+++ b/packages/core/src/code_assist/setup.test.ts
@@ -77,6 +77,27 @@ describe('setupUser for existing user', () => {
     );
   });
 
+  it('should pass httpOptions to CodeAssistServer when provided', async () => {
+    vi.stubEnv('GOOGLE_CLOUD_PROJECT', 'test-project');
+    mockLoad.mockResolvedValue({
+      currentTier: mockPaidTier,
+    });
+    const httpOptions = {
+      headers: {
+        'User-Agent': 'GeminiCLI/1.0.0/gemini-2.0-flash (darwin; arm64)',
+      },
+    };
+    await setupUser({} as OAuth2Client, undefined, httpOptions);
+    expect(CodeAssistServer).toHaveBeenCalledWith(
+      {},
+      'test-project',
+      httpOptions,
+      '',
+      undefined,
+      undefined,
+    );
+  });
+
   it('should ignore GOOGLE_CLOUD_PROJECT when project from server is set', async () => {
     vi.stubEnv('GOOGLE_CLOUD_PROJECT', 'test-project');
     mockLoad.mockResolvedValue({
diff --git a/packages/core/src/code_assist/setup.ts b/packages/core/src/code_assist/setup.ts
index 0f16f422c0..895fabb6bc 100644
--- a/packages/core/src/code_assist/setup.ts
+++ b/packages/core/src/code_assist/setup.ts
@@ -12,6 +12,7 @@ import type {
   OnboardUserRequest,
 } from './types.js';
 import { UserTierId, IneligibleTierReasonCode } from './types.js';
+import type { HttpOptions } from './server.js';
 import { CodeAssistServer } from './server.js';
 import type { AuthClient } from 'google-auth-library';
 import type { ValidationHandler } from '../fallback/types.js';
@@ -77,6 +78,7 @@ export interface UserData {
 export async function setupUser(
   client: AuthClient,
   validationHandler?: ValidationHandler,
+  httpOptions: HttpOptions = {},
 ): Promise<UserData> {
   const projectId =
     process.env['GOOGLE_CLOUD_PROJECT'] ||
@@ -85,7 +87,7 @@ export async function setupUser(
   const caServer = new CodeAssistServer(
     client,
     projectId,
-    {},
+    httpOptions,
     '',
     undefined,
     undefined,