feat(mcp): add `gemini mcp` commands for `add`, `remove` and `list` (#5481)

1 files changed, 139 insertions, 0 deletions

diff --git a/packages/cli/src/commands/mcp/list.ts b/packages/cli/src/commands/mcp/list.ts
new file mode 100644
index 00000000..48ea912e
--- /dev/null
+++ b/packages/cli/src/commands/mcp/list.ts
@@ -0,0 +1,139 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+// File for 'gemini mcp list' command
+import type { CommandModule } from 'yargs';
+import { loadSettings } from '../../config/settings.js';
+import {
+  MCPServerConfig,
+  MCPServerStatus,
+  createTransport,
+} from '@google/gemini-cli-core';
+import { Client } from '@modelcontextprotocol/sdk/client/index.js';
+import { loadExtensions } from '../../config/extension.js';
+
+const COLOR_GREEN = '\u001b[32m';
+const COLOR_YELLOW = '\u001b[33m';
+const COLOR_RED = '\u001b[31m';
+const RESET_COLOR = '\u001b[0m';
+
+async function getMcpServersFromConfig(): Promise<
+  Record<string, MCPServerConfig>
+> {
+  const settings = loadSettings(process.cwd());
+  const extensions = loadExtensions(process.cwd());
+  const mcpServers = { ...(settings.merged.mcpServers || {}) };
+  for (const extension of extensions) {
+    Object.entries(extension.config.mcpServers || {}).forEach(
+      ([key, server]) => {
+        if (mcpServers[key]) {
+          return;
+        }
+        mcpServers[key] = {
+          ...server,
+          extensionName: extension.config.name,
+        };
+      },
+    );
+  }
+  return mcpServers;
+}
+
+async function testMCPConnection(
+  serverName: string,
+  config: MCPServerConfig,
+): Promise<MCPServerStatus> {
+  const client = new Client({
+    name: 'mcp-test-client',
+    version: '0.0.1',
+  });
+
+  let transport;
+  try {
+    // Use the same transport creation logic as core
+    transport = await createTransport(serverName, config, false);
+  } catch (_error) {
+    await client.close();
+    return MCPServerStatus.DISCONNECTED;
+  }
+
+  try {
+    // Attempt actual MCP connection with short timeout
+    await client.connect(transport, { timeout: 5000 }); // 5s timeout
+
+    // Test basic MCP protocol by pinging the server
+    await client.ping();
+
+    await client.close();
+    return MCPServerStatus.CONNECTED;
+  } catch (_error) {
+    await transport.close();
+    return MCPServerStatus.DISCONNECTED;
+  }
+}
+
+async function getServerStatus(
+  serverName: string,
+  server: MCPServerConfig,
+): Promise<MCPServerStatus> {
+  // Test all server types by attempting actual connection
+  return await testMCPConnection(serverName, server);
+}
+
+export async function listMcpServers(): Promise<void> {
+  const mcpServers = await getMcpServersFromConfig();
+  const serverNames = Object.keys(mcpServers);
+
+  if (serverNames.length === 0) {
+    console.log('No MCP servers configured.');
+    return;
+  }
+
+  console.log('Configured MCP servers:\n');
+
+  for (const serverName of serverNames) {
+    const server = mcpServers[serverName];
+
+    const status = await getServerStatus(serverName, server);
+
+    let statusIndicator = '';
+    let statusText = '';
+    switch (status) {
+      case MCPServerStatus.CONNECTED:
+        statusIndicator = COLOR_GREEN + '✓' + RESET_COLOR;
+        statusText = 'Connected';
+        break;
+      case MCPServerStatus.CONNECTING:
+        statusIndicator = COLOR_YELLOW + '…' + RESET_COLOR;
+        statusText = 'Connecting';
+        break;
+      case MCPServerStatus.DISCONNECTED:
+      default:
+        statusIndicator = COLOR_RED + '✗' + RESET_COLOR;
+        statusText = 'Disconnected';
+        break;
+    }
+
+    let serverInfo = `${serverName}: `;
+    if (server.httpUrl) {
+      serverInfo += `${server.httpUrl} (http)`;
+    } else if (server.url) {
+      serverInfo += `${server.url} (sse)`;
+    } else if (server.command) {
+      serverInfo += `${server.command} ${server.args?.join(' ') || ''} (stdio)`;
+    }
+
+    console.log(`${statusIndicator} ${serverInfo} - ${statusText}`);
+  }
+}
+
+export const listCommand: CommandModule = {
+  command: 'list',
+  describe: 'List all configured MCP servers',
+  handler: async () => {
+    await listMcpServers();
+  },
+};