How to integrate Chaser MCP with CrewAI

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Introduction

This guide walks you through connecting Chaser to CrewAI using the Composio tool router. By the end, you'll have a working Chaser agent that can create a new invoice for customer abc ltd, list all customers with overdue invoices, update email address for customer by external id through natural language commands.

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

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

Also integrate Chaser with

TL;DR

Here's what you'll learn:
  • Get a Composio API key and configure your Chaser connection
  • Set up CrewAI with an MCP enabled agent
  • Create a Tool Router session or standalone MCP server for Chaser
  • Build a conversational loop where your agent can execute Chaser operations

What is CrewAI?

CrewAI is a powerful framework for building multi-agent AI systems. It provides primitives for defining agents with specific roles, creating tasks, and orchestrating workflows through crews.

Key features include:

  • Agent Roles: Define specialized agents with specific goals and backstories
  • Task Management: Create tasks with clear descriptions and expected outputs
  • Crew Orchestration: Combine agents and tasks into collaborative workflows
  • MCP Integration: Connect to external tools through Model Context Protocol

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

The Chaser MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Chaser account. It provides structured and secure access to your accounts receivable data, so your agent can create and manage invoices, update customer records, generate credit notes, and retrieve key financial details on your behalf.

  • Automated invoice management: Create, update, and track invoices programmatically—making it easy for your agent to help you stay on top of accounts receivable.
  • Customer information handling: Retrieve, create, and update customer records so your assistant can help onboard new clients or keep customer details up-to-date.
  • Credit note processing: Generate and fetch credit notes, allowing your agent to handle adjustments and reconciliations quickly and accurately.
  • Organization data retrieval: Access up-to-date information about your organization, including IDs, currency settings, and compliance details, for seamless financial operations.
  • Efficient accounts review: Instantly pull lists of customers or credit notes to review outstanding balances, statuses, and financial health—all through conversational prompts.

Supported Tools & Triggers

Tools
Create Contact PersonTool to create a new contact person for a customer in Chaser.
Create InvoiceTool to create a new invoice record in the organization.
Create OverpaymentCreates a new overpayment record in Chaser for tracking customer overpayments.
Delete Contact PersonTool to delete a contact person from a customer record in Chaser.
Get Contact Person by IDTool to get a specific contact person by ID for a customer.
Get Credit Note by IDRetrieve detailed information for a specific credit note by its ID.
Get Credit NotesRetrieves a list of credit notes from Chaser.
Get Current OrganisationTool to retrieve information about the current organisation associated with the API credentials.
Get Customer by IDRetrieve detailed information for a specific customer by their Chaser customer ID.
Get CustomersTool to retrieve a list of all customers associated with the organization.
Get Invoice by IDTool to retrieve detailed information for a specific invoice by its ID.
Get OrganizationTool to retrieve information about the connected organizations.
Get OverpaymentRetrieve detailed information for a specific overpayment by its ID.
Get StatusTool to check the status of the Chaser API.
List Contact PersonsTool to retrieve contact persons for a specific customer.
List InvoicesTool to retrieve invoices with pagination and filtering.
List OverpaymentsTool to retrieve overpayments from Chaser with pagination and filtering.
Create Credit NoteCreates a new credit note record in Chaser for tracking customer credits.
Create CustomerTool to create a new customer record in Chaser.
Update Credit NoteUpdate an existing credit note in Chaser.
Update CustomerTool to update an existing customer's information using their unique Chaser customer ID.
Update InvoiceUpdate an existing invoice in Chaser by its internal ID.
Update Contact PersonTool to update a contact person for a customer in Chaser.
Update OverpaymentTool to update an overpayment record in Chaser.
Upload Invoice PDFUpload a PDF file to an existing invoice in Chaser.
Bulk Upsert CustomersTool to bulk upsert up to 100 customers in a single operation.
Bulk Upsert Contact PersonsTool to bulk insert or update contact persons for a customer.
Bulk Upsert Credit NotesTool to bulk upsert up to 100 credit notes in a single request.
Bulk Upsert InvoicesTool to bulk upsert up to 100 invoices in a single request.
Bulk Upsert OverpaymentsTool to bulk upsert up to 100 overpayments in Chaser, matching by overpayment_id.

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

Prerequisites

Before starting, make sure you have:
  • Python 3.9 or higher
  • A Composio account and API key
  • A Chaser connection authorized in Composio
  • An OpenAI API key for the CrewAI LLM
  • Basic familiarity with Python

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

bash
pip install composio crewai crewai-tools[mcp] python-dotenv
What's happening:
  • composio connects your agent to Chaser via MCP
  • crewai provides Agent, Task, Crew, and LLM primitives
  • crewai-tools[mcp] includes MCP helpers
  • python-dotenv loads environment variables from .env

Set up environment variables

bash
COMPOSIO_API_KEY=your_composio_api_key_here
USER_ID=your_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 with Composio
  • USER_ID scopes the session to your account
  • OPENAI_API_KEY lets CrewAI use your chosen OpenAI model

Import dependencies

python
import os
from composio import Composio
from crewai import Agent, Task, Crew
from crewai_tools import MCPServerAdapter
import dotenv

dotenv.load_dotenv()

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

if not COMPOSIO_API_KEY:
    raise ValueError("COMPOSIO_API_KEY is not set")
if not COMPOSIO_USER_ID:
    raise ValueError("COMPOSIO_USER_ID is not set")
What's happening:
  • CrewAI classes define agents and tasks, and run the workflow
  • MCPServerHTTP connects the agent to an MCP endpoint
  • Composio will give you a short lived Chaser MCP URL

Create a Composio Tool Router session for Chaser

python
composio_client = Composio(api_key=COMPOSIO_API_KEY)
session = composio_client.create(user_id=COMPOSIO_USER_ID, toolkits=["chaser"])

url = session.mcp.url
What's happening:
  • You create a Chaser only session through Composio
  • Composio returns an MCP HTTP URL that exposes Chaser tools

Initialize the MCP Server

python
server_params = {
    "url": url,
    "transport": "streamable-http",
    "headers": {"x-api-key": COMPOSIO_API_KEY},
}

with MCPServerAdapter(server_params) as tools:
    agent = Agent(
        role="Search Assistant",
        goal="Help users search the internet effectively",
        backstory="You are a helpful assistant with access to search tools.",
        tools=tools,
        verbose=False,
        max_iter=10,
    )
What's Happening:
  • Server Configuration: The code sets up connection parameters including the MCP server URL, streamable HTTP transport, and Composio API key authentication.
  • MCP Adapter Bridge: MCPServerAdapter acts as a context manager that converts Composio MCP tools into a CrewAI-compatible format.
  • Agent Setup: Creates a CrewAI Agent with a defined role (Search Assistant), goal (help with internet searches), and access to the MCP tools.
  • Configuration Options: The agent includes settings like verbose=False for clean output and max_iter=10 to prevent infinite loops.
  • Dynamic Tool Usage: Once created, the agent automatically accesses all Composio Search tools and decides when to use them based on user queries.

Create a CLI Chatloop and define the Crew

python
print("Chat started! Type 'exit' or 'quit' to end.\n")

conversation_context = ""

while True:
    user_input = input("You: ").strip()

    if user_input.lower() in ["exit", "quit", "bye"]:
        print("\nGoodbye!")
        break

    if not user_input:
        continue

    conversation_context += f"\nUser: {user_input}\n"
    print("\nAgent is thinking...\n")

    task = Task(
        description=(
            f"Conversation history:\n{conversation_context}\n\n"
            f"Current request: {user_input}"
        ),
        expected_output="A helpful response addressing the user's request",
        agent=agent,
    )

    crew = Crew(agents=[agent], tasks=[task], verbose=False)
    result = crew.kickoff()
    response = str(result)

    conversation_context += f"Agent: {response}\n"
    print(f"Agent: {response}\n")
What's Happening:
  • Interactive CLI Setup: The code creates an infinite loop that continuously prompts for user input and maintains the entire conversation history in a string variable.
  • Input Validation: Empty inputs are ignored to prevent processing blank messages and keep the conversation clean.
  • Context Building: Each user message is appended to the conversation context, which preserves the full dialogue history for better agent responses.
  • Dynamic Task Creation: For every user input, a new Task is created that includes both the full conversation history and the current request as context.
  • Crew Execution: A Crew is instantiated with the agent and task, then kicked off to process the request and generate a response.
  • Response Management: The agent's response is converted to a string, added to the conversation context, and displayed to the user, maintaining conversational continuity.

Complete Code

Here's the complete code to get you started with Chaser and CrewAI:

python
from crewai import Agent, Task, Crew, LLM
from crewai_tools import MCPServerAdapter
from composio import Composio
from dotenv import load_dotenv
import os

load_dotenv()

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.")

# Initialize Composio and create a session
composio = Composio(api_key=COMPOSIO_API_KEY)
session = composio.create(
    user_id=COMPOSIO_USER_ID,
    toolkits=["chaser"],
)
url = session.mcp.url

# Configure LLM
llm = LLM(
    model="gpt-5",
    api_key=os.getenv("OPENAI_API_KEY"),
)

server_params = {
    "url": url,
    "transport": "streamable-http",
    "headers": {"x-api-key": COMPOSIO_API_KEY},
}

with MCPServerAdapter(server_params) as tools:
    agent = Agent(
        role="Search Assistant",
        goal="Help users with internet searches",
        backstory="You are an expert assistant with access to Composio Search tools.",
        tools=tools,
        llm=llm,
        verbose=False,
        max_iter=10,
    )

    print("Chat started! Type 'exit' or 'quit' to end.\n")

    conversation_context = ""

    while True:
        user_input = input("You: ").strip()

        if user_input.lower() in ["exit", "quit", "bye"]:
            print("\nGoodbye!")
            break

        if not user_input:
            continue

        conversation_context += f"\nUser: {user_input}\n"
        print("\nAgent is thinking...\n")

        task = Task(
            description=(
                f"Conversation history:\n{conversation_context}\n\n"
                f"Current request: {user_input}"
            ),
            expected_output="A helpful response addressing the user's request",
            agent=agent,
        )

        crew = Crew(agents=[agent], tasks=[task], verbose=False)
        result = crew.kickoff()
        response = str(result)

        conversation_context += f"Agent: {response}\n"
        print(f"Agent: {response}\n")

Conclusion

You now have a CrewAI agent connected to Chaser through Composio's Tool Router. The agent can perform Chaser operations through natural language commands.

Next steps:

  • Add role-specific instructions to customize agent behavior
  • Plug in more toolkits for multi-app workflows
  • Chain tasks for complex multi-step operations

How to build Chaser MCP Agent with another framework

FAQ

What are the differences in Tool Router MCP and Chaser MCP?

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

Can I use Tool Router MCP with CrewAI?

Yes, you can. CrewAI 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 Chaser tools.

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

Yes, absolutely. You can configure which Chaser 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.

How safe is my data with Composio Tool Router?

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 Chaser data and credentials are handled as safely as possible.

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