mcp-use/dist/src/session.js

A utility library for integrating Model Context Protocol (MCP) with LangChain, Zod, and related tools. Provides helpers for schema conversion, event streaming, and SDK usage.

import { logger } from './logging.js';
export class MCPSession {
    connector;
    autoConnect;
    _sessionInfo = null;
    _tools = [];
    constructor(connector, autoConnect = true) {
        this.connector = connector;
        this.autoConnect = autoConnect;
    }
    async open() {
        await this.connect();
        return this;
    }
    async close() {
        await this.disconnect();
    }
    async connect() {
        await this.connector.connect();
    }
    async disconnect() {
        await this.connector.disconnect();
    }
    async initialize() {
        if (!this.isConnected && this.autoConnect) {
            await this.connect();
        }
        this._sessionInfo = await this.connector.initialize() ?? {};
        await this.discoverTools();
        return this._sessionInfo;
    }
    get isConnected() {
        return this.connector && this.connector.isClientConnected;
    }
    get sessionInfo() {
        return this._sessionInfo;
    }
    get tools() {
        return this._tools;
    }
    async discoverTools() {
        this._tools = this.connector.tools;
        return this._tools;
    }
    async callTool(name, args) {
        if (!this.isConnected && this.autoConnect) {
            await this.connect();
        }
        logger.debug(`MCPSession calling tool '${name}'`);
        return await this.connector.callTool(name, args);
    }
}