2 files changed, 25 insertions, 1 deletions
diff --git a/packages/cli/src/config/config.test.ts b/packages/cli/src/config/config.test.ts
index 4042bf93..6aab4487 100644
--- a/packages/cli/src/config/config.test.ts
+++ b/packages/cli/src/config/config.test.ts
@@ -840,6 +840,7 @@ describe('loadCliConfig ideMode', () => {
     // Explicitly delete TERM_PROGRAM and SANDBOX before each test
     delete process.env.TERM_PROGRAM;
     delete process.env.SANDBOX;
+    delete process.env.GEMINI_CLI_IDE_SERVER_PORT;
   });
 
   afterEach(() => {
@@ -876,6 +877,7 @@ describe('loadCliConfig ideMode', () => {
     process.argv = ['node', 'script.js', '--ide-mode'];
     const argv = await parseArguments();
     process.env.TERM_PROGRAM = 'vscode';
+    process.env.GEMINI_CLI_IDE_SERVER_PORT = '3000';
     const settings: Settings = {};
     const config = await loadCliConfig(settings, [], 'test-session', argv);
     expect(config.getIdeMode()).toBe(true);
@@ -885,6 +887,7 @@ describe('loadCliConfig ideMode', () => {
     process.argv = ['node', 'script.js'];
     const argv = await parseArguments();
     process.env.TERM_PROGRAM = 'vscode';
+    process.env.GEMINI_CLI_IDE_SERVER_PORT = '3000';
     const settings: Settings = { ideMode: true };
     const config = await loadCliConfig(settings, [], 'test-session', argv);
     expect(config.getIdeMode()).toBe(true);
@@ -894,6 +897,7 @@ describe('loadCliConfig ideMode', () => {
     process.argv = ['node', 'script.js', '--ide-mode'];
     const argv = await parseArguments();
     process.env.TERM_PROGRAM = 'vscode';
+    process.env.GEMINI_CLI_IDE_SERVER_PORT = '3000';
     const settings: Settings = { ideMode: false };
     const config = await loadCliConfig(settings, [], 'test-session', argv);
     expect(config.getIdeMode()).toBe(true);
@@ -932,6 +936,7 @@ describe('loadCliConfig ideMode', () => {
     process.argv = ['node', 'script.js', '--ide-mode'];
     const argv = await parseArguments();
     process.env.TERM_PROGRAM = 'vscode';
+    process.env.GEMINI_CLI_IDE_SERVER_PORT = '3000';
     const settings: Settings = {};
     const config = await loadCliConfig(settings, [], 'test-session', argv);
     expect(config.getIdeMode()).toBe(true);
@@ -941,4 +946,16 @@ describe('loadCliConfig ideMode', () => {
     expect(mcpServers['_ide_server'].description).toBe('IDE connection');
     expect(mcpServers['_ide_server'].trust).toBe(false);
   });
+
+  it('should throw an error if ideMode is true and no port is set', async () => {
+    process.argv = ['node', 'script.js', '--ide-mode'];
+    const argv = await parseArguments();
+    process.env.TERM_PROGRAM = 'vscode';
+    const settings: Settings = {};
+    await expect(
+      loadCliConfig(settings, [], 'test-session', argv),
+    ).rejects.toThrow(
+      "Could not run in ide mode, make sure you're running in vs code integrated terminal. Try running in a fresh terminal.",
+    );
+  });
 });
diff --git a/packages/cli/src/config/config.ts b/packages/cli/src/config/config.ts
index bf76fa4c..69708a61 100644
--- a/packages/cli/src/config/config.ts
+++ b/packages/cli/src/config/config.ts
@@ -306,13 +306,20 @@ export async function loadCliConfig(
   }
 
   if (ideMode) {
+    const companionPort = process.env.GEMINI_CLI_IDE_SERVER_PORT;
+    if (!companionPort) {
+      throw new Error(
+        "Could not run in ide mode, make sure you're running in vs code integrated terminal. Try running in a fresh terminal.",
+      );
+    }
+    const httpUrl = `http://localhost:${companionPort}/mcp`;
     mcpServers[IDE_SERVER_NAME] = new MCPServerConfig(
       undefined, // command
       undefined, // args
       undefined, // env
       undefined, // cwd
       undefined, // url
-      'http://localhost:3000/mcp', // httpUrl
+      httpUrl, // httpUrl
       undefined, // headers
       undefined, // tcp
       undefined, // timeout