🧬 refactor: Wire Database Methods into MCP Package via Registry Pattern (#10715)

* Refactor: MCPServersRegistry Singleton Pattern with Dependency Injection for DB methods consumption

* refactor: error handling in MCP initialization and improve logging for MCPServersRegistry instance creation.

- Added checks for mongoose instance in ServerConfigsDB constructor and refined error messages for clarity.
- Reorder and use type imports

---------

Co-authored-by: Atef Bellaaj <slalom.bellaaj@external.daimlertruck.com>
Co-authored-by: Danny Avila <danny@librechat.ai>

packages/api/src/mcp/oauth/OAuthReconnectionManager.test.ts

@@ -1,7 +1,6 @@
 import { TokenMethods } from '@librechat/data-schemas';
 import { FlowStateManager, MCPConnection, MCPOAuthTokens, MCPOptions } from '../..';
 import { MCPManager } from '../MCPManager';
-import { mcpServersRegistry } from '../../mcp/registry/MCPServersRegistry';
 import { OAuthReconnectionManager } from './OAuthReconnectionManager';
 import { OAuthReconnectionTracker } from './OAuthReconnectionTracker';
 
@@ -14,11 +13,15 @@ jest.mock('@librechat/data-schemas', () => ({
   },
 }));
 
+const mockRegistryInstance = {
+  getServerConfig: jest.fn(),
+  getOAuthServers: jest.fn(),
+};
+
 jest.mock('../MCPManager');
 jest.mock('../../mcp/registry/MCPServersRegistry', () => ({
-  mcpServersRegistry: {
-    getServerConfig: jest.fn(),
-    getOAuthServers: jest.fn(),
+  MCPServersRegistry: {
+    getInstance: () => mockRegistryInstance,
   },
 }));
 
@@ -61,7 +64,7 @@ describe('OAuthReconnectionManager', () => {
     } as unknown as jest.Mocked<MCPManager>;
 
     (MCPManager.getInstance as jest.Mock).mockReturnValue(mockMCPManager);
-    (mcpServersRegistry.getServerConfig as jest.Mock).mockResolvedValue({});
+    (mockRegistryInstance.getServerConfig as jest.Mock).mockResolvedValue({});
   });
 
   afterEach(() => {
@@ -159,7 +162,7 @@ describe('OAuthReconnectionManager', () => {
     it('should reconnect eligible servers', async () => {
       const userId = 'user-123';
       const oauthServers = new Set(['server1', 'server2', 'server3']);
-      (mcpServersRegistry.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
+      (mockRegistryInstance.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
 
       // server1: has failed reconnection
       reconnectionTracker.setFailed(userId, 'server1');
@@ -193,7 +196,7 @@ describe('OAuthReconnectionManager', () => {
       mockMCPManager.getUserConnection.mockResolvedValue(
         mockNewConnection as unknown as MCPConnection,
       );
-      (mcpServersRegistry.getServerConfig as jest.Mock).mockResolvedValue({
+      (mockRegistryInstance.getServerConfig as jest.Mock).mockResolvedValue({
         initTimeout: 5000,
       } as unknown as MCPOptions);
 
@@ -224,7 +227,7 @@ describe('OAuthReconnectionManager', () => {
     it('should handle failed reconnection attempts', async () => {
       const userId = 'user-123';
       const oauthServers = new Set(['server1']);
-      (mcpServersRegistry.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
+      (mockRegistryInstance.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
 
       // server1: has valid token
       tokenMethods.findToken.mockResolvedValue({
@@ -235,7 +238,7 @@ describe('OAuthReconnectionManager', () => {
 
       // Mock failed connection
       mockMCPManager.getUserConnection.mockRejectedValue(new Error('Connection failed'));
-      (mcpServersRegistry.getServerConfig as jest.Mock).mockResolvedValue(
+      (mockRegistryInstance.getServerConfig as jest.Mock).mockResolvedValue(
         {} as unknown as MCPOptions,
       );
 
@@ -253,7 +256,7 @@ describe('OAuthReconnectionManager', () => {
     it('should not reconnect servers with expired tokens', async () => {
       const userId = 'user-123';
       const oauthServers = new Set(['server1']);
-      (mcpServersRegistry.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
+      (mockRegistryInstance.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
 
       // server1: has expired token
       tokenMethods.findToken.mockResolvedValue({
@@ -272,7 +275,7 @@ describe('OAuthReconnectionManager', () => {
     it('should handle connection that returns but is not connected', async () => {
       const userId = 'user-123';
       const oauthServers = new Set(['server1']);
-      (mcpServersRegistry.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
+      (mockRegistryInstance.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
 
       tokenMethods.findToken.mockResolvedValue({
         userId,
@@ -288,7 +291,7 @@ describe('OAuthReconnectionManager', () => {
       mockMCPManager.getUserConnection.mockResolvedValue(
         mockConnection as unknown as MCPConnection,
       );
-      (mcpServersRegistry.getServerConfig as jest.Mock).mockResolvedValue(
+      (mockRegistryInstance.getServerConfig as jest.Mock).mockResolvedValue(
         {} as unknown as MCPOptions,
       );
 
@@ -372,7 +375,7 @@ describe('OAuthReconnectionManager', () => {
     it('should not attempt to reconnect servers that have timed out during reconnection', async () => {
       const userId = 'user-123';
       const oauthServers = new Set(['server1', 'server2']);
-      (mcpServersRegistry.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
+      (mockRegistryInstance.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
 
       const now = Date.now();
       jest.setSystemTime(now);
@@ -427,7 +430,7 @@ describe('OAuthReconnectionManager', () => {
       const userId = 'user-123';
       const serverName = 'server1';
       const oauthServers = new Set([serverName]);
-      (mcpServersRegistry.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
+      (mockRegistryInstance.getOAuthServers as jest.Mock).mockResolvedValue(oauthServers);
 
       const now = Date.now();
       jest.setSystemTime(now);
@@ -441,7 +444,7 @@ describe('OAuthReconnectionManager', () => {
 
       // First reconnect attempt - will fail
       mockMCPManager.getUserConnection.mockRejectedValueOnce(new Error('Connection failed'));
-      (mcpServersRegistry.getServerConfig as jest.Mock).mockResolvedValue(
+      (mockRegistryInstance.getServerConfig as jest.Mock).mockResolvedValue(
         {} as unknown as MCPOptions,
       );
 

packages/api/src/mcp/oauth/OAuthReconnectionManager.ts

@@ -4,7 +4,7 @@ import type { MCPOAuthTokens } from './types';
 import { OAuthReconnectionTracker } from './OAuthReconnectionTracker';
 import { FlowStateManager } from '~/flow/manager';
 import { MCPManager } from '~/mcp/MCPManager';
-import { mcpServersRegistry } from '~/mcp/registry/MCPServersRegistry';
+import { MCPServersRegistry } from '~/mcp/registry/MCPServersRegistry';
 
 const DEFAULT_CONNECTION_TIMEOUT_MS = 10_000; // ms
 
@@ -72,7 +72,7 @@ export class OAuthReconnectionManager {
 
     // 1. derive the servers to reconnect
     const serversToReconnect = [];
-    for (const serverName of await mcpServersRegistry.getOAuthServers()) {
+    for (const serverName of await MCPServersRegistry.getInstance().getOAuthServers()) {
       const canReconnect = await this.canReconnect(userId, serverName);
       if (canReconnect) {
         serversToReconnect.push(serverName);
@@ -104,7 +104,7 @@ export class OAuthReconnectionManager {
 
     logger.info(`${logPrefix} Attempting reconnection`);
 
-    const config = await mcpServersRegistry.getServerConfig(serverName, userId);
+    const config = await MCPServersRegistry.getInstance().getServerConfig(serverName, userId);
 
     const cleanupOnFailedReconnect = () => {
       this.reconnectionsTracker.setFailed(userId, serverName);