How to integrate Doppler MCP with LangChain

Connect LangChain to Doppler MCP. Get secrets for staging environment in doppler, add a new secret to marketing project, and more using natural language, with authentication handled for you.

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Doppler is a secrets management platform for organizing and syncing environment variables. It lets teams securely centralize, share, and update secrets across infrastructure.

62 Tools

Introduction

This guide walks you through connecting Doppler to LangChain using the Composio tool router. By the end, you'll have a working Doppler agent that can get secrets for staging environment in doppler, add a new secret to marketing project, list all projects and their environments through natural language commands.

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

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

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TL;DR

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

The Doppler MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Doppler account. It provides structured and secure access to your projects, environments, configs, secrets, service tokens, users, and webhooks, so your agent can inspect projects, review configurations, retrieve and update secrets, create service tokens, and audit workspace resources on your behalf.

  • Project and environment discovery: Have your agent list Doppler projects, inspect project details, and review the environments available within each project.
  • Configuration review: Let the agent list configurations for a project and retrieve a specific config when you need to check how an environment is organized.
  • Secret retrieval and updates: Direct your agent to list secret names, retrieve a specific secret, download configured secrets, or update secrets within a chosen config.
  • Service token management: Instruct your agent to create a service token for a config or list its existing service tokens for review.
  • Workspace and webhook auditing: Have your agent identify the authenticated user, list workplace users, and review webhooks configured for a project.

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 Doppler 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 Doppler 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: ['doppler']
    }
);

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

Configure the agent with the MCP URL

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

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

List Activity Logs

List workplace activity logs with pagination support.

Get Activity Log

Retrieve detailed information about a specific activity log entry.

Add Webhook

Tool to create a new webhook for a Doppler project.

Get Authenticated User Info

Tool to retrieve information about the authenticated user or token.

Get Config Log

Tool to retrieve a specific config log from Doppler.

List Config Logs

Tool to retrieve configuration change logs for a specific config in a project.

Rollback Config Log

Tool to rollback a config to a selected log version.

Clone Config

Tool to clone a branch config including all its secrets.

Create Config

Tool to create a branch config.

Delete Config

Tool to delete a config permanently.

Get Config

Tool to retrieve a specific Doppler config by project and config name.

List Doppler Configs

Tool to list configurations from a Doppler project.

Lock Config

Lock a Doppler config to prevent it from being renamed or deleted.

Unlock Config

Tool to unlock a config.

Update Config

Rename an existing Doppler config within a project.

Create Encrypted Share Link

Create a Doppler Share link for an end-to-end encrypted secret.

Create Plain Text Share Link

Tool to generate a Doppler Share link by sending a plain text secret.

Create Service Token

Tool to create a new service token for a Doppler config.

Delete Service Token

Tool to delete an existing service token from a Doppler config.

Delete Webhook

Tool to delete an existing webhook.

Disable Webhook

Tool to disable an existing Doppler webhook.

Revoke Dynamic Secret Lease

Revoke a dynamic secret lease immediately before its TTL expires.

Enable Webhook

Tool to enable a previously disabled webhook.

Create Environment

Create a new environment in a Doppler project.

Delete Environment

Tool to delete an environment.

Get Environment

Retrieves detailed metadata for a specific Doppler environment within a project.

List Environments

Tool to list all environments in a Doppler project.

Rename Environment

Rename an environment's display name within a Doppler project.

Get Webhook

Tool to retrieve an existing webhook by its slug.

Get Workplace User

Tool to retrieve a specific workplace user by their workplace_user id.

Remove Group Member

Remove a member from a Doppler group.

List Integrations

Tool to retrieve all existing integrations in Doppler.

List Invites

Tool to list open workplace invites.

List Change Requests

List existing change requests in the Doppler workplace.

List Project Members

Tool to list all members of a Doppler project including users, groups, service accounts, and invites.

List Service Tokens

Tool to list all service tokens for a specific Doppler config.

List Workplace Users

Tool to list all users in the Doppler workplace.

List Webhooks

Tool to list all webhooks configured for a Doppler project.

Remove Project Member

Tool to remove a member from a project.

Get Project Member

Retrieve a specific project member's details including their role and environment access permissions.

List Project Permissions

List all available project-level permissions in Doppler.

Get Project Role

Retrieve detailed information about a specific project role in Doppler, including its permissions, display name, identifier, creation timestamp, and whether it's a custom or built-in role.

List Project Roles

Tool to list all available project roles in Doppler.

Create Project

Tool to create a project.

Delete Project

Tool to delete a project permanently.

Get Project Details

Tool to retrieve details of a specific Doppler project by its identifier.

List Doppler Projects

Tool to list all Doppler projects in your workspace.

Delete Secret

Tool to delete a secret from a Doppler config.

Download Secrets

Tool to download secrets from a Doppler config in various formats.

Get Secret

Tool to retrieve a specific secret from a Doppler project config.

List Doppler Secrets

Tool to list all secrets for a specific Doppler config within a project.

List Secret Names

Tool to retrieve the list of secret names from a specific Doppler config.

Update Doppler Secrets

Tool to update secrets in a Doppler config.

Update Secret Note

Tool to update a note for a secret in Doppler.

Update Project

Tool to update an existing Doppler project's name or description.

Update Secret Note

DEPRECATED: Use DopplerSecretsUpdateNote instead.

Update Webhook

Tool to update an existing webhook configuration in Doppler.

Update Workplace Settings

Tool to update workplace settings in Doppler.

Get Workplace Information

Tool to retrieve workplace information from Doppler.

Get Workplace Role

Tool to retrieve workplace role information from Doppler.

List Workplace Roles

Tool to list all workplace roles in your Doppler workspace.

List Workplace Permissions

Retrieves all available workplace permissions in Doppler.

FAQ

Frequently asked questions

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

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

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