How to integrate Telnyx MCP with LangChain

This guide walks you through connecting Telnyx to LangChain using the Composio tool router. By the end, you'll have a working Telnyx agent that can check current telnyx account balance, list recent audit logs for last week, create new sms notification channel through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Telnyx account through Composio's Telnyx MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Telnyx

Api Key

Telnyx is a communications platform offering voice, SMS, and data services on a global private network. It empowers businesses to automate messaging, calls, and notifications at scale.

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Introduction

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

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

Also integrate Telnyx with

OpenAI Agents SDK Claude Agent SDK Claude Code Claude Cowork Codex OpenClaw Hermes CLI Google ADK Vercel AI SDK Mastra AI LlamaIndex CrewAI

TL;DR

Here's what you'll learn:

Get and set up your OpenAI and Composio API keys
Connect your Telnyx project to Composio
Create a Tool Router MCP session for Telnyx
Initialize an MCP client and retrieve Telnyx tools
Build a LangChain agent that can interact with Telnyx
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 Telnyx MCP server, and what's possible with it?

The Telnyx MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Telnyx account. It provides structured and secure access to your Telnyx communications platform, so your agent can manage networks, handle notification channels, monitor usage, and review account activities on your behalf.

Network provisioning and management: Easily create or delete network resources, allowing your agent to spin up new networks or remove unused ones as needed.
Notification channel automation: Set up, configure, or remove notification channels—including SMS, voice, email, or webhook endpoints—so your agent can handle event-driven communications flexibly.
Notification profile and settings control: Group and configure notification profiles and settings, enabling your agent to define how and when notifications are delivered for different events.
Real-time balance monitoring: Retrieve your current account balance and credit details, helping your agent keep tabs on usage and alert you before credits run low.
Comprehensive audit log access: Review detailed audit logs so your agent can surface recent changes, track resource modifications, and help maintain compliance or troubleshoot issues quickly.

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:

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

Step-by-step Guide

Step by step10 STEPS

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

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.

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

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

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 Telnyx functionality through MCP

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 Telnyx tools
Validating that COMPOSIO_USER_ID is also set before proceeding

Create a Tool Router session

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

const url = session.mcp.url;

What's happening:

We're creating a Tool Router session that gives your agent access to Telnyx 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 Telnyx tools as needed

Configure the agent with the MCP URL

const client = new MultiServerMCPClient({
    "telnyx-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 Telnyx MCP server via HTTP
The client is configured with a name and the URL from our Tool Router session
getTools() retrieves all available Telnyx tools that the agent can use
We're creating a LangChain agent using the GPT-5 model

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 Telnyx 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

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 Telnyx 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: ['telnyx']
        }
    );

    const url = session.mcp.url;
    
    const client = new MultiServerMCPClient({
        "telnyx-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 Telnyx 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 Telnyx 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 Telnyx action and event your agent gets out of the box.

Create Network

Tool to create a new network.

Create Notification Channel

Tool to create a notification channel.

Create Notification Profile

Tool to create a notification profile.

Create Notification Setting

Tool to add a notification setting.

Delete Network

Tool to delete a network by ID.

Delete Notification Channel

Tool to delete a notification channel by ID.

Delete Notification Profile

Tool to delete a notification profile by ID.

Delete Notification Setting

Tool to delete a notification setting by ID.

Get Black Box Test Results

Tool to retrieve black box test results from Telnyx SETI Observability.

Get User Balance

Tool to retrieve the current user account balance and credit details.

List Audit Logs

Tool to retrieve a list of audit log entries for your account.

List Connections

Tool to retrieve all connections in your account.

List Dynamic Emergency Endpoints

Tool to list dynamic emergency endpoints.

List Global IP Health Check Types

Tool to list all available global IP health check types.

List Messaging Profiles

Tool to list messaging profiles.

List Messaging URL Domains

Tool to list configured messaging URL domains.

List Mobile Network Operators

Tool to list available mobile network operators.

List Network Interfaces

Tool to list all network interfaces for a specified network.

List Networks

Tool to list all networks in your account.

List Notification Channels

Tool to list all notification channels.

List Notification Event Conditions

Tool to list all notification event conditions.

List Notification Events

Tool to list all notification events with their IDs.

List Notification Profiles

Tool to list all notification profiles.

List Phone Numbers

Tool to list phone numbers associated with your account.

List SSO Authentication Providers

Tool to retrieve all configured SSO authentication providers.

Retrieve Network

Tool to retrieve details of a specific network by ID.

Retrieve Notification Channel

Tool to retrieve a notification channel by ID.

Retrieve Notification Profile

Tool to retrieve a notification profile by ID.

Retrieve Notification Setting

Tool to retrieve a notification setting by ID.

Update Network

Tool to update details of an existing network.

FRAMEWORKS

How to build Telnyx MCP Agent with another framework

OpenAI Agents SDK

Use Telnyx MCP with OpenAI Agents SDK

Claude Agent SDK

Use Telnyx MCP with Claude Agent SDK

Claude Code

Use Telnyx MCP with Claude Code

Claude Cowork

Use Telnyx MCP with Claude Cowork

Codex

Use Telnyx MCP with Codex

OpenClaw

Use Telnyx MCP with OpenClaw

Hermes

Use Telnyx MCP with Hermes

CLI

Use Telnyx MCP with CLI

Google ADK

Use Telnyx MCP with Google ADK

Vercel AI SDK

Use Telnyx MCP with Vercel AI SDK

Mastra AI

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LlamaIndex

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CrewAI

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MORE TOOLKITS

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Slack

Oauth2

Slack is a channel-based messaging platform for teams and organizations. It helps people collaborate in real time, share files, and connect all their tools in one place.

Gong

BasicOauth2

Gong is a platform for video meetings, call recording, and team collaboration. It helps teams capture conversations, analyze calls, and turn insights into action.

FAQ

Frequently asked questions

With a standalone Telnyx MCP server, the agents and LLMs can only access a fixed set of Telnyx tools tied to that server. However, with the Composio Tool Router, agents can dynamically load tools from Telnyx 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 Telnyx tools.

Yes, absolutely. You can configure which Telnyx 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 Telnyx data and credentials are handled as safely as possible.

Start with Telnyx.It takes 30 seconds.

Managed auth, hosted MCP servers, and every Telnyx tool your agent needs.Free to start.

Start building

Customer stories

Teams ship real agents on Composio

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Karan skipped his own birthday party to fix our critical issue. It was 10pm and he diverted his Waymo to help us instead. This really sets the bar — it shows the commitment you need when users rely on your software.

Harsha Gaddipati

Co-founder, Slashy

A lot of students tell us that the moment their connected tools start talking to each other inside Opennote feels almost magical. The agent just knows them, and it's immensely helped keep new users on the platform.

Abhi Arya

Co-founder, Opennote

We chose Composio over Pipedream because it delivered depth where it mattered — niche tools and tricky edge cases other platforms simply ignored. That gave us confidence to scale without compromising.

Nirman Dave

CEO, Zams

As a solo builder, shipping fast is life or death. The only way I can outcompete incumbents is by outmanoeuvring them. Getting bogged down managing agent auth would have been a death sentence.

Ryan Yu

Founder, Extra Thursday

Before Composio, adding tool integrations was slow and resource-intensive. Each one could take weeks of engineering time, and maintaining them meant constantly keeping up with API changes.

Tomisin Jenrola

Founder & CEO, SwarmZero

With hands-on help from their founder, we integrated Gmail and Google Drive in just 30 minutes. This level of personal support and commitment is exactly what startups should strive for.

Jerome Leclanche

Co-Founder, Ingram Technologies

How to integrate Telnyx MCP with LangChain

Connect Telnyx without auth hassles

Introduction

Also integrate Telnyx with

TL;DR

What is LangChain?

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

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

What is Composio SDK?

How the Composio SDK works

Step-by-step Guide

Prerequisites

Getting API Keys for OpenAI and Composio

Install dependencies

Set up environment variables

Import dependencies

Initialize Composio client

Create a Tool Router session

Configure the agent with the MCP URL

Set up interactive chat interface

Run the application

Complete Code

Conclusion

Supported Tools

How to build Telnyx MCP Agent with another framework

OpenAI Agents SDK

Claude Agent SDK

Claude Code

Claude Cowork

Codex

OpenClaw

Hermes

CLI

Google ADK

Vercel AI SDK

Mastra AI

LlamaIndex

CrewAI

Explore Other Toolkits

Gmail

Outlook

Slack

Gong

Frequently asked questions

What are the differences in Tool Router MCP and Telnyx MCP?+

Can I use Tool Router MCP with LangChain?+

Can I manage the permissions and scopes for Telnyx while using Tool Router?+

How safe is my data with Composio Tool Router?+

Start with Telnyx.It takes 30 seconds.

Teams ship real agents on Composio