🔧 fix: Update Token Calculations/Mapping, MCP env Initialization (#6406)

* fix: Enhance MCP initialization to process environment variables

* fix: only build tokenCountMap with messages that are being used in the payload

* fix: Adjust maxContextTokens calculation to account for maxOutputTokens

* refactor: Make processMCPEnv optional in MCPManager initialization

* chore: Bump version of librechat-data-provider to 0.7.73

packages/data-provider/package.json

@@ -1,6 +1,6 @@
 {
   "name": "librechat-data-provider",
-  "version": "0.7.72",
+  "version": "0.7.73",
   "description": "data services for librechat apps",
   "main": "dist/index.js",
   "module": "dist/index.es.js",

packages/data-provider/src/mcp.ts

@@ -85,3 +85,26 @@ export const MCPOptionsSchema = z.union([
 ]);
 
 export const MCPServersSchema = z.record(z.string(), MCPOptionsSchema);
+
+export type MCPOptions = z.infer<typeof MCPOptionsSchema>;
+
+/**
+ * Recursively processes an object to replace environment variables in string values
+ * @param {MCPOptions} obj - The object to process
+ * @returns {MCPOptions} - The processed object with environment variables replaced
+ */
+export function processMCPEnv(obj: MCPOptions): MCPOptions {
+  if (obj === null || obj === undefined) {
+    return obj;
+  }
+
+  if ('env' in obj && obj.env) {
+    const processedEnv: Record<string, string> = {};
+    for (const [key, value] of Object.entries(obj.env)) {
+      processedEnv[key] = extractEnvVariable(value);
+    }
+    obj.env = processedEnv;
+  }
+
+  return obj;
+}

packages/mcp/src/manager.ts

@@ -1,5 +1,5 @@
 import { CallToolResultSchema } from '@modelcontextprotocol/sdk/types.js';
-import type { JsonSchemaType } from 'librechat-data-provider';
+import type { JsonSchemaType, MCPOptions } from 'librechat-data-provider';
 import type { Logger } from 'winston';
 import type * as t from './types/mcp';
 import { formatToolContent } from './parsers';
@@ -31,13 +31,17 @@ export class MCPManager {
     return MCPManager.instance;
   }
 
-  public async initializeMCP(mcpServers: t.MCPServers): Promise<void> {
+  public async initializeMCP(
+    mcpServers: t.MCPServers,
+    processMCPEnv?: (obj: MCPOptions) => MCPOptions,
+  ): Promise<void> {
     this.logger.info('[MCP] Initializing servers');
 
     const entries = Object.entries(mcpServers);
     const initializedServers = new Set();
     const connectionResults = await Promise.allSettled(
-      entries.map(async ([serverName, config], i) => {
+      entries.map(async ([serverName, _config], i) => {
+        const config = processMCPEnv ? processMCPEnv(_config) : _config;
         const connection = new MCPConnection(serverName, config, this.logger);
 
         connection.on('connectionChange', (state) => {