How to integrate Brex MCP with CrewAI

This guide walks you through connecting Brex to CrewAI using the Composio tool router. By the end, you'll have a working Brex agent that can create a new card for our intern, get the latest account statement pdf, add an expense for last week's conference through natural language commands. This guide will help you understand how to give your CrewAI agent real control over a Brex account through Composio's Brex MCP server. Before we dive in, let's take a quick look at the key ideas and tools involved.

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Brex

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Brex provides corporate credit cards and spend management tailored for startups and tech businesses. It helps optimize company cash flow, streamline accounting, and accelerate business growth.

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Introduction

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

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

Also integrate Brex with

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

TL;DR

Here's what you'll learn:

Get a Composio API key and configure your Brex connection
Set up CrewAI with an MCP enabled agent
Create a Tool Router session or standalone MCP server for Brex
Build a conversational loop where your agent can execute Brex 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 Brex MCP server, and what's possible with it?

The Brex MCP server is an implementation of the Model Context Protocol that connects your AI agent and assistants like Claude, Cursor, etc directly to your Brex account. It provides structured and secure access to your company's financial tools, so your agent can perform actions like managing cards, tracking expenses, creating budgets, and retrieving account details on your behalf.

Card creation and management: Instantly issue new cards, assign them to users or vendors, and control spending limits via your agent.
Automated expense tracking: Let your agent create and log expenses, helping you keep company finances organized and up to date.
Budget and department setup: Quickly create budgets for teams or projects and set up new departments without manual effort.
Account and statement retrieval: Fetch detailed account information and download statements whenever you need financial insights or records.
User and location management: Add new users or locations to your Brex account, making it easy to scale as your business grows.

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 step08 STEPS

Prerequisites

Before starting, make sure you have:

Python 3.9 or higher
A Composio account and API key
A Brex 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 Brex 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 Brex MCP URL

Create a Composio Tool Router session for Brex

python

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

url = session.mcp.url

What's happening:

You create a Brex only session through Composio
Composio returns an MCP HTTP URL that exposes Brex 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 Brex 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=["brex"],
)
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 Brex through Composio's Tool Router. The agent can perform Brex 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

TOOLS

Supported Tools

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

Add Webhook Group Members

Add webhook subscription members to a webhook group.

Archive Budget

Archive a budget to mark it as inactive and prevent future expenses.

Archive Spend Limit

Archive a spend limit in Brex.

Create Budget

Create a new budget for departments or projects.

Create Spend Limit (Budget V1)

Tool to create a new Spend Limit (Budget) in Brex.

Create Card

Create a new card and assign it to a user.

Create Department

Create a new department.

Create Document Upload for Referral

Create a document upload URL for a referral and return a pre-signed S3 upload URL.

Create Expense

Create a new expense.

Create Custom Field

Create a new custom field in Brex.

Create Field Values

Create custom field values for a specific Brex field.

Create Location

Create a new location.

Create Referral Request

Tool to create a new referral to Brex for onboarding.

Create Spend Limit

Tool to create a spend limit in Brex.

Create Job Title

Create a new job title.

Create User

Create a new user in the Brex account.

Create Vendor

Create a new vendor in Brex for payment operations.

Create Webhook Group

Tool to create a webhook group for targeting webhook subscriptions.

Create Webhook Subscription

Delete Field

Tool to delete a custom field by Brex ID.

Delete Field Values

Delete custom field values for a specific field.

Delete Vendor

Delete a vendor by ID.

Get Account Statements

Get finalized statements for the primary cash account.

Get Budget Details

Get detailed information about a specific budget.

Get Card Details

Get detailed information about a specific card.

Get Card Expense

Tool to retrieve detailed information about a specific card expense by its ID.

Get Card Number

Get card number, CVV, and expiration date for a specific card.

Get Card Transactions

Get settled card transactions for the primary card account.

Get Company Cash Accounts

Retrieve all cash (deposit) accounts for the company.

Get Company Details

Get company information associated with the OAuth2 access token.

Get Department By ID

Get detailed information about a specific department by ID.

Get Expense

Tool to get details of a specific expense by ID.

Get Field By ID

Tool to retrieve a custom field by its Brex ID.

Get Field Value By ID

Tool to retrieve a specific field value by field ID and field value ID.

Get Legal Entity

Tool to retrieve a legal entity by its ID from Brex.

Get Location By ID

Get detailed information about a specific location by ID.

Get Referral By ID

Tool to retrieve a specific referral by its ID from Brex.

Get Spend Limit By ID

Tool to get detailed information about a specific spend limit by its ID.

Get Spend Limits

Get spend limits configuration.

Get Title by ID

Get detailed information about a specific job title by ID.

Get Transaction by ID

Get details of a specific transaction by ID.

Get Card Transactions

Get card transactions from the primary Brex account.

Get Transactions by Amount Range

Get card transactions filtered by amount range and date period.

Search Transactions by Description

Search and filter card transactions by description text.

Get User Limit

Retrieves the monthly spending limit and available balance for a specific Brex user.

Get User Profile

Get user profile information from Brex Team API.

Get Vendor By ID

Tool to get vendor details by ID.

Get Webhook Group

Tool to retrieve details of a specific webhook group by ID.

Get Webhook Subscription

Tool to retrieve details of a specific webhook subscription by ID.

List Budget Programs

Tool to list all budget programs in the organization.

List Budgets

List all budgets and show available amounts across all cards.

List Card Accounts

Tool to list all card accounts for the company.

List Cards

List all cards associated with the account.

List Card Statements

Tool to list finalized statements for primary card accounts.

List Departments

List all departments in the organization.

List Expenses

Tool to list expenses from the Brex platform.

List Field Values

Tool to list values under a custom field.

List Legal Entities

Tool to list all legal entities in the Brex account with pagination support.

List Locations

List all locations in the organization.

List Referrals

Tool to list all referrals created in the Brex account.

List Job Titles

List all job titles in the organization.

List Transfers

Lists transfers for the account.

List Trips

Lists trips according to the filters passed in the query string.

List Users

List all users in the Brex account.

List Vendors

List all vendors.

List Webhook Group Members

Tool to list all members of a webhook group.

List Webhook Groups

Tool to list all webhook groups.

List Webhook Secrets

Tool to retrieve webhook signing secrets for validating incoming webhook messages from Brex.

List Webhook Subscriptions

Tool to list all registered webhook subscriptions.

Create Receipt Match

Creates a receipt match request and returns a pre-signed S3 upload URI.

Create Receipt Upload for Expense

Creates a receipt upload request for a specific card expense and returns a pre-signed S3 upload URL.

Set User Limit

Set or update the monthly spending limit for a Brex user.

Transfer Card

Transfer a card to a different user.

Update Budget

Update an existing budget's configuration in Brex.

Update Spend Limit (V1)

Tool to update a Spend Limit (budget) using the v1 API.

Update Card Limits

Update spending limits and controls for a Brex card.

Update Card Status

Update the status of a Brex card by locking, unlocking, or terminating it.

Update Expense

Tool to update an expense by its ID.

Update Field

Tool to update a custom field in Brex.

Update Field Values

Tool to update custom field values in Brex for a specific field.

Update Spend Limit

Updates an existing Brex spend limit by its ID.

Update User

Update user details.

Update Vendor

Tool to update vendor information in Brex.

Update Webhook Subscription

Updates an existing Brex webhook subscription's configuration.

FRAMEWORKS

How to build Brex MCP Agent with another framework

OpenAI Agents SDK

Use Brex MCP with OpenAI Agents SDK

Claude Agent SDK

Use Brex MCP with Claude Agent SDK

Claude Code

Use Brex MCP with Claude Code

Claude Cowork

Use Brex MCP with Claude Cowork

Codex

Use Brex MCP with Codex

OpenClaw

Use Brex MCP with OpenClaw

Hermes

Use Brex MCP with Hermes

CLI

Use Brex MCP with CLI

Google ADK

Use Brex MCP with Google ADK

LangChain

Use Brex MCP with LangChain

Vercel AI SDK

Use Brex MCP with Vercel AI SDK

Mastra AI

Use Brex MCP with Mastra AI

LlamaIndex

Use Brex MCP with LlamaIndex

MORE TOOLKITS

Explore Other Toolkits

Toolkit marketplace

Stripe

Api KeyOauth2

Stripe is a global online payments platform offering APIs for managing payments, customers, and subscriptions. Trusted by businesses for secure, efficient, and scalable payment processing worldwide.

Alpha vantage

Api Key

Alpha Vantage is a financial data platform offering real-time and historical stock market APIs. Get instant, reliable access to equities, forex, and technical analysis data for smarter trading decisions.

Altoviz

Api Key

Altoviz is a cloud-based billing and invoicing platform for businesses. It streamlines online payments, expense tracking, and customizable invoice management.

Benzinga

Api Key

Benzinga provides real-time financial news and data APIs for market coverage. It helps you track breaking news and actionable market insights instantly.

FAQ

Frequently asked questions

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

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 Brex tools.

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

Start with Brex.It takes 30 seconds.

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

Start building

Customer stories

Teams ship real agents on Composio

GET STARTED FOR FREE BOOK A DEMO

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 Brex MCP with CrewAI

Connect Brex without auth hassles

Introduction

Also integrate Brex with

TL;DR

What is CrewAI?

What is the Brex 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

Create a Composio Tool Router session for Brex

Initialize the MCP Server

Create a CLI Chatloop and define the Crew

Complete Code

Conclusion

Supported Tools

How to build Brex MCP Agent with another framework

OpenAI Agents SDK

Claude Agent SDK

Claude Code

Claude Cowork

Codex

OpenClaw

Hermes

CLI

Google ADK

LangChain

Vercel AI SDK

Mastra AI

LlamaIndex

Explore Other Toolkits

Stripe

Alpha vantage

Altoviz

Benzinga

Frequently asked questions

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

Can I use Tool Router MCP with CrewAI?+

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

How safe is my data with Composio Tool Router?+

Start with Brex.It takes 30 seconds.

Teams ship real agents on Composio