How to integrate Teltel MCP with LangChain

This guide walks you through connecting Teltel to LangChain using the Composio tool router. By the end, you'll have a working Teltel agent that can retrieve all missed calls from today, list all sms messages from specific number, show teltel users added this week through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Teltel account through Composio's Teltel MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Teltel is a telecom operator and software platform for automated voice and SMS communication. It streamlines contact center management and programmable communication for businesses.

26 Tools

Introduction

This guide walks you through connecting Teltel to LangChain using the Composio tool router. By the end, you'll have a working Teltel agent that can retrieve all missed calls from today, list all sms messages from specific number, show teltel users added this week through natural language commands.

This guide will help you understand how to give your LangChain agent real control over a Teltel account through Composio's Teltel MCP server.

Before we dive in, let's take a quick look at the key ideas and tools involved.

Also integrate Teltel with

OpenAI Agents SDKClaude Agent SDKClaude CodeClaude CoworkCodexOpenClawHermesCLIGoogle ADKVercel AI SDKMastra AILlamaIndexCrewAI

TL;DR

Here's what you'll learn:
  • Get and set up your OpenAI and Composio API keys
  • Connect your Teltel project to Composio
  • Create a Tool Router MCP session for Teltel
  • Initialize an MCP client and retrieve Teltel tools
  • Build a LangChain agent that can interact with Teltel
  • Set up an interactive chat interface for testing

What is LangChain?

LangChain is a framework for developing applications powered by language models. It provides tools and abstractions for building agents that can reason, use tools, and maintain conversation context.

Key features include:

  • Agent Framework: Build agents that can use tools and make decisions
  • MCP Integration: Connect to external services through Model Context Protocol adapters
  • Memory Management: Maintain conversation history across interactions
  • Multi-Provider Support: Works with OpenAI, Anthropic, and other LLM providers

What is the Teltel MCP server, and what's possible with it?

The Teltel MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Teltel account. It provides structured and secure access to your telecom data, so your agent can retrieve call logs, manage SMS messages, access user records, and handle inbound SMS events automatically.

  • Comprehensive call log retrieval: Quickly fetch and filter detailed lists of your recent and historical calls, including duration, status, and time for easy reporting or analysis.
  • SMS message management: Effortlessly access sent and received SMS logs, filter messages by sender, recipient, status, or date, and keep your communications organized.
  • User directory synchronization: Retrieve up-to-date lists of all users in your Teltel account, making it simple to manage contact center agents or team members.
  • Automated inbound SMS handling: Set up your agent to receive and process incoming SMS via webhook, so you never miss an important customer message or support request.

What is the Composio tool router, and how does it fit here?

What is Composio SDK?

Composio's Composio SDK helps agents find the right tools for a task at runtime. You can plug in multiple toolkits (like Gmail, HubSpot, and GitHub), and the agent will identify the relevant app and action to complete multi-step workflows. This can reduce token usage and improve the reliability of tool calls. Read more here: Getting started with Composio SDK

The tool router generates a secure MCP URL that your agents can access to perform actions.

How the Composio SDK works

The Composio SDK follows a three-phase workflow:

  1. Discovery: Searches for tools matching your task and returns relevant toolkits with their details.
  2. Authentication: Checks for active connections. If missing, creates an auth config and returns a connection URL via Auth Link.
  3. Execution: Executes the action using the authenticated connection.

Step-by-step Guide

Step by step10 STEPS
1

Prerequisites

Before starting this tutorial, make sure you have:
  • Python 3.10 or higher installed on your system
  • A Composio account with an API key
  • An OpenAI API key
  • Basic familiarity with Python and async programming
2

Getting API Keys for OpenAI and Composio

OpenAI API Key
  • Go to the OpenAI dashboard and create an API key. You'll need credits to use the models, or you can connect to another model provider.
  • Keep the API key safe.
Composio API Key
  • Log in to the Composio dashboard.
  • Navigate to your API settings and generate a new API key.
  • Store this key securely as you'll need it for authentication.
3

Install dependencies

npm install @composio/langchain @langchain/core @langchain/openai @langchain/mcp-adapters dotenv

Install the required packages for LangChain with MCP support.

What's happening:

  • @composio/langchain provides Composio integration for LangChain
  • @langchain/mcp-adapters enables MCP client connections
  • @langchain/core is the core agent framework
  • dotenv/config loads environment variables
4

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
COMPOSIO_USER_ID=your_composio_user_id_here
OPENAI_API_KEY=your_openai_api_key_here

Create a .env file in your project root.

What's happening:

  • COMPOSIO_API_KEY authenticates your requests to Composio's API
  • COMPOSIO_USER_ID identifies the user for session management
  • OPENAI_API_KEY enables access to OpenAI's language models
5

Import dependencies

import { Composio } from '@composio/core';
import { LangchainProvider } from '@composio/langchain';
import { MultiServerMCPClient } from "@langchain/mcp-adapters";
import { createAgent } from "langchain";
import * as readline from 'readline';
import 'dotenv/config';

dotenv.config();
What's happening:
  • We're importing LangChain's MCP adapter and Composio SDK
  • The dotenv/config import loads environment variables from your .env file
  • This setup prepares the foundation for connecting LangChain with Teltel functionality through MCP
6

Initialize Composio client

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.COMPOSIO_USER_ID;

if (!composioApiKey) throw new Error('COMPOSIO_API_KEY is not set');
if (!userId) throw new Error('COMPOSIO_USER_ID is not set');

async function main() {
    const composio = new Composio({
        apiKey: composioApiKey as string,
        provider: new LangchainProvider()
    });
What's happening:
  • We're loading the COMPOSIO_API_KEY from environment variables and validating it exists
  • Creating a Composio instance that will manage our connection to Teltel tools
  • Validating that COMPOSIO_USER_ID is also set before proceeding
7

Create a Tool Router session

const session = await composio.create(
    userId as string,
    {
        toolkits: ['teltel']
    }
);

const url = session.mcp.url;
What's happening:
  • We're creating a Tool Router session that gives your agent access to Teltel tools
  • The create method takes the user ID and specifies which toolkits should be available
  • The returned session.mcp.url is the MCP server URL that your agent will use
  • This approach allows the agent to dynamically load and use Teltel tools as needed
8

Configure the agent with the MCP URL

const client = new MultiServerMCPClient({
    "teltel-agent": {
        transport: "http",
        url: url,
        headers: {
            "x-api-key": process.env.COMPOSIO_API_KEY
        }
    }
});

const tools = await client.getTools();

const agent = createAgent({ model: "gpt-5", tools });
What's happening:
  • We're creating a MultiServerMCPClient that connects to our Teltel MCP server via HTTP
  • The client is configured with a name and the URL from our Tool Router session
  • getTools() retrieves all available Teltel tools that the agent can use
  • We're creating a LangChain agent using the GPT-5 model
9

Set up interactive chat interface

let conversationHistory: any[] = [];

console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
console.log("Ask any Teltel related question or task to the agent.\n");

const rl = readline.createInterface({
    input: process.stdin,
    output: process.stdout,
    prompt: 'You: '
});

rl.prompt();

rl.on('line', async (userInput: string) => {
    const trimmedInput = userInput.trim();

    if (['exit', 'quit', 'bye'].includes(trimmedInput.toLowerCase())) {
        console.log("\nGoodbye!");
        rl.close();
        process.exit(0);
    }

    if (!trimmedInput) {
        rl.prompt();
        return;
    }

    conversationHistory.push({ role: "user", content: trimmedInput });
    console.log("\nAgent is thinking...\n");

    const response = await agent.invoke({ messages: conversationHistory });
    conversationHistory = response.messages;

    const finalResponse = response.messages[response.messages.length - 1]?.content;
    console.log(`Agent: ${finalResponse}\n`);
        
        rl.prompt();
    });

    rl.on('close', () => {
        console.log('\n👋 Session ended.');
        process.exit(0);
    });
What's happening:
  • We initialize an empty conversationHistory list to maintain context across interactions
  • A readline interface is used to continuously accept user input from the command line
  • When a user types a message, it's added to the conversation history and sent to the agent
  • The agent processes the request using the invoke() method with the full conversation history
  • Users can type 'exit', 'quit', or 'bye' to end the chat session gracefully
10

Run the application

main().catch((err) => {
    console.error('Fatal error:', err);
    process.exit(1);
});
What's happening:
  • We call the main() function to start the application

Complete Code

Here's the complete code to get you started with Teltel and LangChain:

import { Composio } from '@composio/core';
import { LangchainProvider } from '@composio/langchain';
import { MultiServerMCPClient } from "@langchain/mcp-adapters";  
import { createAgent } from "langchain";
import * as readline from 'readline';
import 'dotenv/config';

const composioApiKey = process.env.COMPOSIO_API_KEY;
const userId = process.env.COMPOSIO_USER_ID;

if (!composioApiKey) throw new Error('COMPOSIO_API_KEY is not set');
if (!userId) throw new Error('COMPOSIO_USER_ID is not set');

async function main() {
    const composio = new Composio({
        apiKey: composioApiKey as string,
        provider: new LangchainProvider()
    });

    const session = await composio.create(
        userId as string,
        {
            toolkits: ['teltel']
        }
    );

    const url = session.mcp.url;
    
    const client = new MultiServerMCPClient({
        "teltel-agent": {
            transport: "http",
            url: url,
            headers: {
                "x-api-key": process.env.COMPOSIO_API_KEY
            }
        }
    });
    
    const tools = await client.getTools();
  
    const agent = createAgent({ model: "gpt-5", tools });
    
    let conversationHistory: any[] = [];
    
    console.log("Chat started! Type 'exit' or 'quit' to end the conversation.\n");
    console.log("Ask any Teltel related question or task to the agent.\n");
    
    const rl = readline.createInterface({
        input: process.stdin,
        output: process.stdout,
        prompt: 'You: '
    });

    rl.prompt();

    rl.on('line', async (userInput: string) => {
        const trimmedInput = userInput.trim();
        
        if (['exit', 'quit', 'bye'].includes(trimmedInput.toLowerCase())) {
            console.log("\nGoodbye!");
            rl.close();
            process.exit(0);
        }
        
        if (!trimmedInput) {
            rl.prompt();
            return;
        }
        
        conversationHistory.push({ role: "user", content: trimmedInput });
        console.log("\nAgent is thinking...\n");
        
        const response = await agent.invoke({ messages: conversationHistory });
        conversationHistory = response.messages;
        
        const finalResponse = response.messages[response.messages.length - 1]?.content;
        console.log(`Agent: ${finalResponse}\n`);
        
        rl.prompt();
    });

    rl.on('close', () => {
        console.log('\nSession ended.');
        process.exit(0);
    });
}

main().catch((err) => {
    console.error('Fatal error:', err);
    process.exit(1);
});

Conclusion

You've successfully built a LangChain agent that can interact with Teltel through Composio's Tool Router.

Key features of this implementation:

  • Dynamic tool loading through Composio's Tool Router
  • Conversation history maintenance for context-aware responses
  • Async Python provides clean, efficient execution of agent workflows
You can extend this further by adding error handling, implementing specific business logic, or integrating additional Composio toolkits to create multi-app workflows.
TOOLS

Supported Tools

Every Teltel action and event your agent gets out of the box.

Create Autodialer Custom Status

Tool to create a custom status for autodialer contacts.

Create Call

Tool to create a call between two participants.

Create User Status

Tool to create a user status in TelTel.

Delete Autodialer Custom Status

Tool to delete an autodialer custom status by ID.

Delete User Status

Tool to delete a user status by ID.

Get Account Balance

Tool to retrieve the account balance for your TelTel account.

Get Call List

Tool to retrieve a list of calls with details (duration, time, status).

Get Country

Tool to retrieve country resource information by ID from TelTel.

Get SMS List

Tool to retrieve a list of sent (outbox) or received (inbox) SMS messages from TelTel.

Get User Caller ID Groups

Tool to retrieve caller ID groups for a specific user.

Get Users List

Tool to retrieve a list of users from your TelTel account.

List Autodialer Actions

Tool to retrieve the action history for an autodialer campaign.

List Autodialer Contacts

Tool to retrieve the contact list for an autodialer campaign.

List Autodialer Custom Statuses

Tool to retrieve list of autodialer custom statuses.

List Autodialer Campaigns

Tool to retrieve a list of autodialer campaigns from TelTel.

List Available Countries

Tool to get the list of countries where DID numbers are available for purchase.

List Country Price Groups

Tool to retrieve phone number price groups available in a specific country.

List Devices

Tool to retrieve a list of devices from your TelTel account.

List My Numbers

Tool to retrieve a list of phone numbers (DIDs) owned by the account.

List DID Orders

Tool to retrieve a list of DID (phone number) orders from TelTel.

List User Statuses

Tool to retrieve a list of all user statuses in TelTel.

Lookup Phone Number

Tool to perform HLR (Home Location Register) lookup for phone numbers via TelTel API.

Receive Inbound SMS

Tool to process inbound SMS webhook data from TelTel.

Set User Status

Tool to set a user's status in TelTel.

Update Autodialer Custom Status

Tool to update an autodialer custom status value by ID.

Update User Status

Tool to update an existing user status in TelTel.

FRAMEWORKS

How to build Teltel MCP Agent with another framework

OpenAI Agents SDK logo

OpenAI Agents SDK

Use Teltel MCP with OpenAI Agents SDK

Claude Agent SDK logo

Claude Agent SDK

Use Teltel MCP with Claude Agent SDK

Claude Code logo

Claude Code

Use Teltel MCP with Claude Code

Claude Cowork logo

Claude Cowork

Use Teltel MCP with Claude Cowork

Codex logo

Codex

Use Teltel MCP with Codex

OpenClaw logo

OpenClaw

Use Teltel MCP with OpenClaw

Hermes logo

Hermes

Use Teltel MCP with Hermes

CLI logo

CLI

Use Teltel MCP with CLI

Google ADK logo

Google ADK

Use Teltel MCP with Google ADK

Vercel AI SDK logo

Vercel AI SDK

Use Teltel MCP with Vercel AI SDK

Mastra AI logo

Mastra AI

Use Teltel MCP with Mastra AI

LlamaIndex logo

LlamaIndex

Use Teltel MCP with LlamaIndex

CrewAI logo

CrewAI

Use Teltel MCP with CrewAI

FAQ

Frequently asked questions

With a standalone Teltel MCP server, the agents and LLMs can only access a fixed set of Teltel tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Teltel and many other apps based on the task at hand, all through a single MCP endpoint.

Yes, you can. LangChain fully supports MCP integration. You get structured tool calling, message history handling, and model orchestration while Tool Router takes care of discovering and serving the right Teltel tools.

Yes, absolutely. You can configure which Teltel scopes and actions are allowed when connecting your account to Composio. You can also bring your own OAuth credentials or API configuration so you keep full control over what the agent can do.

All sensitive data such as tokens, keys, and configuration is fully encrypted at rest and in transit. Composio is SOC 2 Type 2 compliant and follows strict security practices so your Teltel data and credentials are handled as safely as possible.

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