✨ feat: Add Normalization for MCP Server Names (#7421)

api/server/services/MCP.js

@@ -1,5 +1,6 @@
 const { z } = require('zod');
 const { tool } = require('@langchain/core/tools');
+const { normalizeServerName } = require('librechat-mcp');
 const { Constants: AgentConstants, Providers } = require('@librechat/agents');
 const {
   Constants,
@@ -38,6 +39,7 @@ async function createMCPTool({ req, toolKey, provider: _provider }) {
   }
 
   const [toolName, serverName] = toolKey.split(Constants.mcp_delimiter);
+  const normalizedToolKey = `${toolName}${Constants.mcp_delimiter}${normalizeServerName(serverName)}`;
 
   if (!req.user?.id) {
     logger.error(
@@ -83,7 +85,7 @@ async function createMCPTool({ req, toolKey, provider: _provider }) {
 
   const toolInstance = tool(_call, {
     schema,
-    name: toolKey,
+    name: normalizedToolKey,
     description: description || '',
     responseFormat: AgentConstants.CONTENT_AND_ARTIFACT,
   });

packages/mcp/src/index.ts

@@ -1,5 +1,7 @@
 /* MCP */
 export * from './manager';
+/* Utilities */
+export * from './utils';
 /* Flow */
 export * from './flow/manager';
 /* types */

packages/mcp/src/utils.test.ts

@@ -0,0 +1,28 @@
+import { normalizeServerName } from './utils';
+
+describe('normalizeServerName', () => {
+  it('should not modify server names that already match the pattern', () => {
+    const result = normalizeServerName('valid-server_name.123');
+    expect(result).toBe('valid-server_name.123');
+  });
+
+  it('should normalize server names with non-ASCII characters', () => {
+    const result = normalizeServerName('我的服务');
+    // Should generate a fallback name with a hash
+    expect(result).toMatch(/^server_\d+$/);
+    expect(result).toMatch(/^[a-zA-Z0-9_.-]+$/);
+  });
+
+  it('should normalize server names with special characters', () => {
+    const result = normalizeServerName('server@name!');
+    // The actual result doesn't have the trailing underscore after trimming
+    expect(result).toBe('server_name');
+    expect(result).toMatch(/^[a-zA-Z0-9_.-]+$/);
+  });
+
+  it('should trim leading and trailing underscores', () => {
+    const result = normalizeServerName('!server-name!');
+    expect(result).toBe('server-name');
+    expect(result).toMatch(/^[a-zA-Z0-9_.-]+$/);
+  });
+});

packages/mcp/src/utils.ts

@@ -0,0 +1,30 @@
+/**
+ * Normalizes a server name to match the pattern ^[a-zA-Z0-9_.-]+$
+ * This is required for Azure OpenAI models with Tool Calling
+ */
+export function normalizeServerName(serverName: string): string {
+  // Check if the server name already matches the pattern
+  if (/^[a-zA-Z0-9_.-]+$/.test(serverName)) {
+    return serverName;
+  }
+
+  /** Replace non-matching characters with underscores.
+    This preserves the general structure while ensuring compatibility. 
+    Trims leading/trailing underscores
+    */
+  const normalized = serverName.replace(/[^a-zA-Z0-9_.-]/g, '_').replace(/^_+|_+$/g, '');
+
+  // If the result is empty (e.g., all characters were non-ASCII and got trimmed),
+  // generate a fallback name to ensure we always have a valid function name
+  if (!normalized) {
+    /** Hash of the original name to ensure uniqueness */
+    let hash = 0;
+    for (let i = 0; i < serverName.length; i++) {
+      hash = (hash << 5) - hash + serverName.charCodeAt(i);
+      hash |= 0; // Convert to 32bit integer
+    }
+    return `server_${Math.abs(hash)}`;
+  }
+
+  return normalized;
+}