Add support for allowed/excluded MCP server names in settings (#4135)

Co-authored-by: Scott Densmore <scottdensmore@mac.com>

packages/cli/src/config/config.test.ts

@@ -725,6 +725,66 @@ describe('loadCliConfig with allowed-mcp-server-names', () => {
     const config = await loadCliConfig(baseSettings, [], 'test-session', argv);
     expect(config.getMcpServers()).toEqual({});
   });
+
+  it('should read allowMCPServers from settings', async () => {
+    process.argv = ['node', 'script.js'];
+    const argv = await parseArguments();
+    const settings: Settings = {
+      ...baseSettings,
+      allowMCPServers: ['server1', 'server2'],
+    };
+    const config = await loadCliConfig(settings, [], 'test-session', argv);
+    expect(config.getMcpServers()).toEqual({
+      server1: { url: 'http://localhost:8080' },
+      server2: { url: 'http://localhost:8081' },
+    });
+  });
+
+  it('should read excludeMCPServers from settings', async () => {
+    process.argv = ['node', 'script.js'];
+    const argv = await parseArguments();
+    const settings: Settings = {
+      ...baseSettings,
+      excludeMCPServers: ['server1', 'server2'],
+    };
+    const config = await loadCliConfig(settings, [], 'test-session', argv);
+    expect(config.getMcpServers()).toEqual({
+      server3: { url: 'http://localhost:8082' },
+    });
+  });
+
+  it('should override allowMCPServers with excludeMCPServers if overlapping ', async () => {
+    process.argv = ['node', 'script.js'];
+    const argv = await parseArguments();
+    const settings: Settings = {
+      ...baseSettings,
+      excludeMCPServers: ['server1'],
+      allowMCPServers: ['server1', 'server2'],
+    };
+    const config = await loadCliConfig(settings, [], 'test-session', argv);
+    expect(config.getMcpServers()).toEqual({
+      server2: { url: 'http://localhost:8081' },
+    });
+  });
+
+  it('should prioritize mcp server flag if set ', async () => {
+    process.argv = [
+      'node',
+      'script.js',
+      '--allowed-mcp-server-names',
+      'server1',
+    ];
+    const argv = await parseArguments();
+    const settings: Settings = {
+      ...baseSettings,
+      excludeMCPServers: ['server1'],
+      allowMCPServers: ['server2'],
+    };
+    const config = await loadCliConfig(settings, [], 'test-session', argv);
+    expect(config.getMcpServers()).toEqual({
+      server1: { url: 'http://localhost:8080' },
+    });
+  });
 });
 
 describe('loadCliConfig extensions', () => {

packages/cli/src/config/config.ts

@@ -274,6 +274,26 @@ export async function loadCliConfig(
   let mcpServers = mergeMcpServers(settings, activeExtensions);
   const excludeTools = mergeExcludeTools(settings, activeExtensions);
 
+  if (!argv.allowedMcpServerNames) {
+    if (settings.allowMCPServers) {
+      const allowedNames = new Set(settings.allowMCPServers.filter(Boolean));
+      if (allowedNames.size > 0) {
+        mcpServers = Object.fromEntries(
+          Object.entries(mcpServers).filter(([key]) => allowedNames.has(key)),
+        );
+      }
+    }
+
+    if (settings.excludeMCPServers) {
+      const excludedNames = new Set(settings.excludeMCPServers.filter(Boolean));
+      if (excludedNames.size > 0) {
+        mcpServers = Object.fromEntries(
+          Object.entries(mcpServers).filter(([key]) => !excludedNames.has(key)),
+        );
+      }
+    }
+  }
+
   if (argv.allowedMcpServerNames) {
     const allowedNames = new Set(argv.allowedMcpServerNames.filter(Boolean));
     if (allowedNames.size > 0) {

packages/cli/src/config/settings.test.ts

@@ -223,6 +223,7 @@ describe('Settings Loading and Merging', () => {
       const systemSettingsContent = {
         theme: 'system-theme',
         sandbox: false,
+        allowMCPServers: ['server1', 'server2'],
         telemetry: { enabled: false },
       };
       const userSettingsContent = {
@@ -234,6 +235,7 @@ describe('Settings Loading and Merging', () => {
         sandbox: false,
         coreTools: ['tool1'],
         contextFileName: 'WORKSPACE_CONTEXT.md',
+        allowMCPServers: ['server1', 'server2', 'server3'],
       };
 
       (fs.readFileSync as Mock).mockImplementation(
@@ -259,6 +261,7 @@ describe('Settings Loading and Merging', () => {
         telemetry: { enabled: false },
         coreTools: ['tool1'],
         contextFileName: 'WORKSPACE_CONTEXT.md',
+        allowMCPServers: ['server1', 'server2'],
       });
     });
 

packages/cli/src/config/settings.ts

@@ -64,6 +64,8 @@ export interface Settings {
   toolCallCommand?: string;
   mcpServerCommand?: string;
   mcpServers?: Record<string, MCPServerConfig>;
+  allowMCPServers?: string[];
+  excludeMCPServers?: string[];
   showMemoryUsage?: boolean;
   contextFileName?: string | string[];
   accessibility?: AccessibilitySettings;