How to integrate Reply io MCP with Google ADK

This guide walks you through connecting Reply io to Google ADK using the Composio tool router. By the end, you'll have a working Reply io agent that can list all active campaigns this week, show contacts added to sales lists, delete a campaign by campaign id through natural language commands. This guide will help you understand how to give your Google ADK agent real control over a Reply io account through Composio's Reply io MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Reply io

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Reply.io is an AI-powered sales engagement platform for automating sales outreach across multiple channels. Boosts lead conversion and sales productivity through integrated workflows.

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Introduction

This guide will help you understand how to give your Google ADK agent real control over a Reply io account through Composio's Reply io MCP server.

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

Also integrate Reply io with

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

TL;DR

Here's what you'll learn:

Get a Reply io account set up and connected to Composio
Install the Google ADK and Composio packages
Create a Composio Tool Router session for Reply io
Build an agent that connects to Reply io through MCP
Interact with Reply io using natural language

What is Google ADK?

Google ADK (Agents Development Kit) is Google's framework for building AI agents powered by Gemini models. It provides tools for creating agents that can use external services through the Model Context Protocol.

Key features include:

Gemini Integration: Native support for Google's Gemini models
MCP Toolset: Built-in support for Model Context Protocol tools
Streamable HTTP: Connect to external services through streamable HTTP
CLI and Web UI: Run agents via command line or web interface

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

The Reply io MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Reply io account. It provides structured and secure access to your sales engagement platform, so your agent can manage campaigns, handle contacts, organize sequences, and automate routine sales operations on your behalf.

Campaign and sequence management: Effortlessly list, browse, and delete campaigns or sequences to keep your outreach organized and up to date.
Contact and list organization: Let your agent fetch, review, and organize your Reply io contacts and contact lists for targeted sales actions.
Email account administration: Retrieve all connected email accounts or remove outdated ones, making sure your sales tools stay streamlined.
User and access control: Easily remove users or generate unique identifiers for tasks, maintaining security and clarity in your team’s workflow.
Automated data retrieval: Quickly pull up paginated lists of campaigns, sequences, email accounts, or contact lists to inform your sales strategies and next steps.

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 step09 STEPS

Prerequisites

Before starting, make sure you have:

A Google API key for Gemini models
A Composio account and API key
Python 3.9 or later installed
Basic familiarity with Python

Getting API Keys for Google and Composio

Google API Key

Go to Google AI Studio and create an API key.
Copy the key and keep it safe. You will put this in GOOGLE_API_KEY.

Composio API Key and User ID

Log in to the Composio dashboard.
Go to Settings → API Keys and copy your Composio API key. Use this for COMPOSIO_API_KEY.
Decide on a stable user identifier to scope sessions, often your email or a user ID. Use this for COMPOSIO_USER_ID.

Install dependencies

bash

pip install google-adk composio python-dotenv

Inside your virtual environment, install the required packages.

What's happening:

google-adk is Google's Agents Development Kit
composio connects your agent to Reply io via MCP
python-dotenv loads environment variables

Set up ADK project

bash

adk create my_agent

Set up a new Google ADK project.

What's happening:

This creates an agent folder with a root agent file and .env file

Set environment variables

bash

GOOGLE_API_KEY=your-google-api-key
COMPOSIO_API_KEY=your-composio-api-key
COMPOSIO_USER_ID=your-user-id-or-email

Save all your credentials in the .env file.

What's happening:

GOOGLE_API_KEY authenticates with Google's Gemini models
COMPOSIO_API_KEY authenticates with Composio
COMPOSIO_USER_ID identifies the user for session management

Import modules and validate environment

python

import os
import warnings

from composio import Composio
from dotenv import load_dotenv
from google.adk.agents.llm_agent import Agent
from google.adk.tools.mcp_tool.mcp_session_manager import StreamableHTTPConnectionParams
from google.adk.tools.mcp_tool.mcp_toolset import McpToolset

load_dotenv()

warnings.filterwarnings("ignore", message=".*BaseAuthenticatedTool.*")

GOOGLE_API_KEY = os.getenv("GOOGLE_API_KEY")
COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
COMPOSIO_USER_ID = os.getenv("COMPOSIO_USER_ID")

if not GOOGLE_API_KEY:
    raise ValueError("GOOGLE_API_KEY is not set in the environment.")
if not COMPOSIO_API_KEY:
    raise ValueError("COMPOSIO_API_KEY is not set in the environment.")
if not COMPOSIO_USER_ID:
    raise ValueError("COMPOSIO_USER_ID is not set in the environment.")

What's happening:

os reads environment variables
Composio is the main Composio SDK client
GoogleProvider declares that you are using Google ADK as the agent runtime
Agent is the Google ADK LLM agent class
McpToolset lets the ADK agent call MCP tools over HTTP

Create Composio client and Tool Router session

python

composio_client = Composio(api_key=COMPOSIO_API_KEY)

composio_session = composio_client.create(
    user_id=COMPOSIO_USER_ID,
    toolkits=["reply_io"],
)

COMPOSIO_MCP_URL = composio_session.mcp.url,
print(f"Composio MCP URL: {COMPOSIO_MCP_URL}")

What's happening:

Authenticates to Composio with your API key
Declares Google ADK as the provider
Spins up a short-lived MCP endpoint for your user and selected toolkit
Stores the MCP HTTP URL for the ADK MCP integration

Set up the McpToolset and create the Agent

python

composio_toolset = McpToolset(
    connection_params=StreamableHTTPConnectionParams(
        url=COMPOSIO_MCP_URL,
        headers={"x-api-key": COMPOSIO_API_KEY}
    )
)

root_agent = Agent(
    model="gemini-2.5-flash",
    name="composio_agent",
    description="An agent that uses Composio tools to perform actions.",
    instruction=(
        "You are a helpful assistant connected to Composio. "
        "You have the following tools available: "
        "COMPOSIO_SEARCH_TOOLS, COMPOSIO_MULTI_EXECUTE_TOOL, "
        "COMPOSIO_MANAGE_CONNECTIONS, COMPOSIO_REMOTE_BASH_TOOL, COMPOSIO_REMOTE_WORKBENCH. "
        "Use these tools to help users with Reply io operations."
    ),
    tools=[composio_toolset],
)

print("\nAgent setup complete. You can now run this agent directly ;)")

What's happening:

Connects the ADK agent to the Composio MCP endpoint through McpToolset
Uses Gemini as the model powering the agent
Lists exact tool names in instruction to reduce misnamed tool calls

Run the agent

bash

# Run in CLI mode
adk run my_agent

# Or run in web UI mode
adk web

Execute the agent from the project root. The web command opens a web portal where you can chat with the agent.

What's happening:

adk run runs the agent in CLI mode
adk web . opens a web UI for interactive testing

Complete Code

Here's the complete code to get you started with Reply io and Google ADK:

python

import os
import warnings

from composio import Composio
from composio_google import GoogleProvider
from dotenv import load_dotenv
from google.adk.agents.llm_agent import Agent
from google.adk.tools.mcp_tool.mcp_session_manager import StreamableHTTPConnectionParams
from google.adk.tools.mcp_tool.mcp_toolset import McpToolset

load_dotenv()
warnings.filterwarnings("ignore", message=".*BaseAuthenticatedTool.*")

GOOGLE_API_KEY = os.getenv("GOOGLE_API_KEY")
COMPOSIO_API_KEY = os.getenv("COMPOSIO_API_KEY")
COMPOSIO_USER_ID = os.getenv("COMPOSIO_USER_ID")

if not GOOGLE_API_KEY:
    raise ValueError("GOOGLE_API_KEY is not set in the environment.")
if not COMPOSIO_API_KEY:
    raise ValueError("COMPOSIO_API_KEY is not set in the environment.")
if not COMPOSIO_USER_ID:
    raise ValueError("COMPOSIO_USER_ID is not set in the environment.")

composio_client = Composio(api_key=COMPOSIO_API_KEY, provider=GoogleProvider())

composio_session = composio_client.create(
    user_id=COMPOSIO_USER_ID,
    toolkits=["reply_io"],
)

COMPOSIO_MCP_URL = composio_session.mcp.url


composio_toolset = McpToolset(
    connection_params=StreamableHTTPConnectionParams(
        url=COMPOSIO_MCP_URL,
        headers={"x-api-key": COMPOSIO_API_KEY}
    )
)

root_agent = Agent(
    model="gemini-2.5-flash",
    name="composio_agent",
    description="An agent that uses Composio tools to perform actions.",
    instruction=(
        "You are a helpful assistant connected to Composio. "
        "You have the following tools available: "
        "COMPOSIO_SEARCH_TOOLS, COMPOSIO_MULTI_EXECUTE_TOOL, "
        "COMPOSIO_MANAGE_CONNECTIONS, COMPOSIO_REMOTE_BASH_TOOL, COMPOSIO_REMOTE_WORKBENCH. "
        "Use these tools to help users with Reply io operations."
    ),  
    tools=[composio_toolset],
)

print("\nAgent setup complete. You can now run this agent directly ;)")

Conclusion

You've successfully integrated Reply io with the Google ADK through Composio's MCP Tool Router. Your agent can now interact with Reply io using natural language commands.

Key takeaways:

The Tool Router approach dynamically routes requests to the appropriate Reply io tools
Environment variables keep your credentials secure and separate from code
Clear agent instructions reduce tool calling errors
The ADK web UI provides an interactive interface for testing and development

You can extend this setup by adding more toolkits to the toolkits array in your session configuration.

TOOLS

Supported Tools

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

Add Contact to Sequence

Move an existing contact to a sequence in Reply.

Archive Sequence

Tool to archive a sequence.

Clear Contact Status

Tool to clear statuses from contacts.

Connect Exchange Account via OAuth

Tool to initiate OAuth connection for an Exchange email account.

Connect Gmail Account

Tool to initiate Gmail account connection via OAuth.

Create Contact

Tool to create a new contact in Reply.

Create Sequence Step

Tool to add a new step to an existing sequence.

Delete Contact

Tool to delete a contact.

Delete Email Account

Tool to delete a specific email account.

Delete Schedule

Tool to delete a schedule.

Delete Sequence

Tool to delete a sequence.

Delete User

Tool to delete a user.

Generate ULID

Get Contact by ID

Tool to retrieve a contact by ID.

Get Contact Status

Tool to get contact status.

Get Current User

Tool to get the current authenticated user's ID.

Reply.io Get Disconnected Email Accounts

Tool to list email accounts that are currently disconnected due to authentication or connection errors.

Get Sequence By ID

Tool to retrieve detailed information about a sequence by its ID.

Get Sequence Contacts Extended

Tool to retrieve all contacts enrolled in a sequence with additional details.

Get Sequence Step by ID

Tool to retrieve details of a specific sequence step.

List Contacts Basic

Tool to list contacts.

Reply.io List Email Accounts

Tool to list all email accounts.

Reply.io List Lists

Tool to list all contact lists.

List Sequences

Tool to retrieve a paginated list of sequences.

List Sequence Steps

Tool to retrieve all steps in a sequence.

Pause Sequence

Tool to pause a running sequence.

Remove Contact From Sequence

Tool to remove a contact from a sequence.

Bulk Remove Contacts from Sequence

Tool to bulk remove multiple contacts from a sequence at once.

Search Contacts by Email

Tool to search contacts by email.

Set Contact Status

Tool to set the status of one or more contacts.

Start Sequence

Tool to start a sequence.

Update Contact

Tool to update an existing contact's information.

Update Email Account

Tool to update an existing email account with custom SMTP/IMAP settings.

FRAMEWORKS

How to build Reply io MCP Agent with another framework

OpenAI Agents SDK

Use Reply io MCP with OpenAI Agents SDK

Claude Agent SDK

Use Reply io MCP with Claude Agent SDK

Claude Code

Use Reply io MCP with Claude Code

Claude Cowork

Use Reply io MCP with Claude Cowork

Codex

Use Reply io MCP with Codex

OpenClaw

Use Reply io MCP with OpenClaw

Hermes

Use Reply io MCP with Hermes

CLI

Use Reply io MCP with CLI

LangChain

Use Reply io MCP with LangChain

Vercel AI SDK

Use Reply io MCP with Vercel AI SDK

Mastra AI

Use Reply io MCP with Mastra AI

LlamaIndex

Use Reply io MCP with LlamaIndex

CrewAI

Use Reply io MCP with CrewAI

MORE TOOLKITS

Explore Other Toolkits

Toolkit marketplace

Aeroleads

Api Key

Aeroleads is a B2B lead generation platform for finding business emails and phone numbers. Grow your sales pipeline faster with powerful prospecting tools.

Autobound

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Autobound is an AI-powered sales engagement platform that crafts hyper-personalized outreach and insights. It helps sales teams boost response rates and close more deals through tailored content and recommendations.

Better proposals

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Better Proposals is a web-based tool for crafting and sending professional proposals. It helps teams impress clients and close deals faster with slick, easy-to-use templates.

Bidsketch

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Bidsketch is a proposal software that helps businesses create professional proposals quickly and efficiently. It streamlines the proposal process, saving time while boosting client win rates.

FAQ

Frequently asked questions

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

Yes, you can. Google ADK 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 Reply io tools.

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

Start with Reply io.It takes 30 seconds.

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

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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 Reply io MCP with Google ADK

Connect Reply io without auth hassles

Introduction

Also integrate Reply io with

TL;DR

What is Google ADK?

What is the Reply io 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 Google and Composio

Install dependencies

Set up ADK project

Set environment variables

Import modules and validate environment

Create Composio client and Tool Router session

Set up the McpToolset and create the Agent

Run the agent

Complete Code

Conclusion

Supported Tools

How to build Reply io MCP Agent with another framework

OpenAI Agents SDK

Claude Agent SDK

Claude Code

Claude Cowork

Codex

OpenClaw

Hermes

CLI

LangChain

Vercel AI SDK

Mastra AI

LlamaIndex

CrewAI

Explore Other Toolkits

Aeroleads

Autobound

Better proposals

Bidsketch

Frequently asked questions

What are the differences in Tool Router MCP and Reply io MCP?+

Can I use Tool Router MCP with Google ADK?+

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

How safe is my data with Composio Tool Router?+

Start with Reply io.It takes 30 seconds.

Teams ship real agents on Composio