How to integrate Countdown api MCP with LangChain

This guide walks you through connecting Countdown api to LangChain using the Composio tool router. By the end, you'll have a working Countdown api agent that can list all your ebay data collections, start processing requests for a collection, get autocomplete suggestions for 'wireless earbuds' through natural language commands. This guide will help you understand how to give your LangChain agent real control over a Countdown api account through Composio's Countdown api MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

Countdown api logoCountdown api
Api Key

Countdown API gives you real-time, structured eBay product data, reviews, and seller feedback. Perfect for powering price monitoring, product research, or marketplace analytics workflows.

25 Tools

Introduction

This guide walks you through connecting Countdown api to LangChain using the Composio tool router. By the end, you'll have a working Countdown api agent that can list all your ebay data collections, start processing requests for a collection, get autocomplete suggestions for 'wireless earbuds' through natural language commands.

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

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

Also integrate Countdown api with

TL;DR

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

The Countdown api MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Countdown api account. It provides structured and secure access to real-time eBay marketplace data, so your agent can perform actions like searching eBay products, managing collections, retrieving seller feedback, and automating product data workflows on your behalf.

  • eBay product search and autocomplete: Instantly fetch eBay autocomplete suggestions and help agents surface relevant product search terms and ideas in real time.
  • Collection management and orchestration: Create, update, list, or delete collections to batch and organize multiple eBay data requests for streamlined marketplace analysis.
  • Automated collection processing: Start or clear queued requests within a collection, making it easy to control and automate data gathering operations from eBay.
  • Destination setup and notifications: Set up or remove destinations for results and notifications, ensuring your agent can manage where and how you receive processed eBay data.
  • Access to rich eBay metadata: Retrieve detailed collection information, product details, customer reviews, and seller feedback to power analytics and business decisions.

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 Countdown api 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 Countdown api 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: ['countdown_api']
    }
);

const url = session.mcp.url;
What's happening:
  • We're creating a Tool Router session that gives your agent access to Countdown api 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 Countdown api tools as needed
8

Configure the agent with the MCP URL

const client = new MultiServerMCPClient({
    "countdown_api-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 Countdown api MCP server via HTTP
  • The client is configured with a name and the URL from our Tool Router session
  • getTools() retrieves all available Countdown api 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 Countdown api 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 Countdown api 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: ['countdown_api']
        }
    );

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

Clear Collection Requests

Clears (removes) all pending requests from a collection.

Create a new collection

Tool to create a new collection.

Get Collection

Tool to retrieve details for a single collection by ID.

List Collections

Tool to list all collections for the authenticated account.

Start Collection

Start processing a collection's queued requests on the Countdown API.

Update an existing collection

Update an existing collection's settings.

eBay Autocomplete

Tool to fetch eBay autocomplete suggestions.

Create Collection Request

Tool to create new requests within a collection for bulk eBay data retrieval.

Create Destination

Creates a cloud storage destination where batch result sets will be automatically uploaded.

Delete Collection

Tool to delete a collection and its configuration by ID.

Delete Destination

Tool to delete a destination by ID.

Delete Single Request

Delete a specific request from a Countdown API collection by its ID.

List Destinations

Tool to list all destinations configured for the account.

Find Collection Requests

Tool to find requests in a collection by custom_id or search query.

Get Account Information

Tool to retrieve account usage and current platform status.

List Error Logs

Tool to list error logs from collection executions.

Export Requests CSV

Export all requests from a collection as downloadable CSV files.

Export Requests as JSON

Tool to download all requests in a collection as JSON.

Update Single Request

Tool to modify parameters of an existing request in a collection.

Get Result Set

Tool to retrieve a collection run's result set payload.

List Result Sets

Tool to list result sets produced by a collection.

Resend Result Set Webhook

Resend the webhook notification for a collection's result set.

Stop All Collections

Tool to stop all collections.

Stop Collection

Tool to stop (pause) a single collection’s processing by ID.

Update Destination

Tool to update a destination's configuration by ID.

FAQ

Frequently asked questions

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

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

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