How to integrate Brex MCP with Hermes

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Introduction

Hermes is a 24/7 autonomous agent that lives on your computer or server — it remembers what it learns and evolves as your usage grows.

This guide explains the easiest and most robust way to connect your Brex account to Hermes. You can do this through either Composio Connect CLI or Composio Connect MCP. For personal use we recommend the CLI, but you won't go wrong with MCP either.

Also integrate Brex with

What is Composio Connect?

Composio Connect is a consumer offering that lets anyone plug 1,000+ applications directly into their agent harness — including Hermes. It can:

  • Search and load tools from relevant toolkits on-demand, reducing context usage.
  • Chain multiple tools to accomplish complex workflows via a remote workbench, without excessive back-and-forth with the LLM.
  • Manage app authentication end-to-end with zero manual overhead.

Integrating Brex with Hermes

Using Composio Connect CLI

1. Install the Composio CLI

Run the install script directly, or paste https://composio.dev/hermes into your Hermes chat box to have it installed for you.

bash
curl -fsSL https://composio.dev/install | bash
Hermes authenticating with Composio

2. Authenticate

Once the CLI is installed, ask Hermes to authenticate with Composio.

3. Connect to Brex

Ask your agent to connect to Brex, or simply request any Brex-related task. Hermes will prompt you to authenticate and authorize access.

4. Done. You're all set with a new Brex connection.


Using Composio Connect MCP

1. Get your MCP URL and API Key

Go to dashboard.composio.dev and copy your Connect MCP URL and API key.

Copy MCP URL and API key from Composio dashboard

2. Open the Hermes config file

bash
nano ~/.hermes/config.yaml

3. Add the Composio Connect MCP server

bash
mcp_servers:
  composio:
    url: "https://connect.composio.dev/mcp"
    headers:
      x-consumer-api-key: "YOUR_COMPOSIO_API_KEY"
    connect_timeout: 60
    timeout: 180

Save with Ctrl + O, Enter, then exit with Ctrl + X.

4. Restart your Hermes agent

Once restarted, ask your agent to connect to Brex or request any Brex-related task. It will prompt you to authenticate and authorize access.

5. Done!

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.

Supported Tools & Triggers

Tools
Add Webhook Group MembersAdd webhook subscription members to a webhook group.
Archive BudgetArchive a budget to mark it as inactive and prevent future expenses.
Archive Spend LimitArchive a spend limit in Brex.
Create BudgetCreate a new budget for departments or projects.
Create Spend Limit (Budget V1)Tool to create a new Spend Limit (Budget) in Brex.
Create CardCreate a new card and assign it to a user.
Create DepartmentCreate a new department.
Create Document Upload for ReferralCreate a document upload URL for a referral and return a pre-signed S3 upload URL.
Create ExpenseCreate a new expense.
Create Custom FieldCreate a new custom field in Brex.
Create Field ValuesCreate custom field values for a specific Brex field.
Create LocationCreate a new location.
Create Referral RequestTool to create a new referral to Brex for onboarding.
Create Spend LimitTool to create a spend limit in Brex.
Create Job TitleCreate a new job title.
Create UserCreate a new user in the Brex account.
Create VendorCreate a new vendor in Brex for payment operations.
Create Webhook GroupTool to create a webhook group for targeting webhook subscriptions.
Create Webhook SubscriptionRegister a new webhook subscription to receive real-time notifications for Brex events.
Delete FieldTool to delete a custom field by Brex ID.
Delete Field ValuesDelete custom field values for a specific field.
Delete VendorDelete a vendor by ID.
Get Account StatementsGet finalized statements for the primary cash account.
Get Budget DetailsGet detailed information about a specific budget.
Get Card DetailsGet detailed information about a specific card.
Get Card ExpenseTool to retrieve detailed information about a specific card expense by its ID.
Get Card NumberGet card number, CVV, and expiration date for a specific card.
Get Card TransactionsGet settled card transactions for the primary card account.
Get Company Cash AccountsRetrieve all cash (deposit) accounts for the company.
Get Company DetailsGet company information associated with the OAuth2 access token.
Get Department By IDGet detailed information about a specific department by ID.
Get ExpenseTool to get details of a specific expense by ID.
Get Field By IDTool to retrieve a custom field by its Brex ID.
Get Field Value By IDTool to retrieve a specific field value by field ID and field value ID.
Get Legal EntityTool to retrieve a legal entity by its ID from Brex.
Get Location By IDGet detailed information about a specific location by ID.
Get Referral By IDTool to retrieve a specific referral by its ID from Brex.
Get Spend Limit By IDTool to get detailed information about a specific spend limit by its ID.
Get Spend LimitsGet spend limits configuration.
Get Title by IDGet detailed information about a specific job title by ID.
Get Transaction by IDGet details of a specific transaction by ID.
Get Card TransactionsGet card transactions from the primary Brex account.
Get Transactions by Amount RangeGet card transactions filtered by amount range and date period.
Search Transactions by DescriptionSearch and filter card transactions by description text.
Get User LimitRetrieves the monthly spending limit and available balance for a specific Brex user.
Get User ProfileGet user profile information from Brex Team API.
Get Vendor By IDTool to get vendor details by ID.
Get Webhook GroupTool to retrieve details of a specific webhook group by ID.
Get Webhook SubscriptionTool to retrieve details of a specific webhook subscription by ID.
List Budget ProgramsTool to list all budget programs in the organization.
List BudgetsList all budgets and show available amounts across all cards.
List Card AccountsTool to list all card accounts for the company.
List CardsList all cards associated with the account.
List Card StatementsTool to list finalized statements for primary card accounts.
List DepartmentsList all departments in the organization.
List ExpensesTool to list expenses from the Brex platform.
List Field ValuesTool to list values under a custom field.
List Legal EntitiesTool to list all legal entities in the Brex account with pagination support.
List LocationsList all locations in the organization.
List ReferralsTool to list all referrals created in the Brex account.
List Job TitlesList all job titles in the organization.
List TransfersLists transfers for the account.
List TripsLists trips according to the filters passed in the query string.
List UsersList all users in the Brex account.
List VendorsList all vendors.
List Webhook Group MembersTool to list all members of a webhook group.
List Webhook GroupsTool to list all webhook groups.
List Webhook SecretsTool to retrieve webhook signing secrets for validating incoming webhook messages from Brex.
List Webhook SubscriptionsTool to list all registered webhook subscriptions.
Create Receipt MatchCreates a receipt match request and returns a pre-signed S3 upload URI.
Create Receipt Upload for ExpenseCreates a receipt upload request for a specific card expense and returns a pre-signed S3 upload URL.
Set User LimitSet or update the monthly spending limit for a Brex user.
Transfer CardTransfer a card to a different user.
Update BudgetUpdate an existing budget's configuration in Brex.
Update Spend Limit (V1)Tool to update a Spend Limit (budget) using the v1 API.
Update Card LimitsUpdate spending limits and controls for a Brex card.
Update Card StatusUpdate the status of a Brex card by locking, unlocking, or terminating it.
Update ExpenseTool to update an expense by its ID.
Update FieldTool to update a custom field in Brex.
Update Field ValuesTool to update custom field values in Brex for a specific field.
Update Spend LimitUpdates an existing Brex spend limit by its ID.
Update UserUpdate user details.
Update VendorTool to update vendor information in Brex.
Update Webhook SubscriptionUpdates an existing Brex webhook subscription's configuration.

Way Forward

With Brex connected, Hermes can now act on your behalf whenever it detects a relevant task or you ask it to.

From here, you can extend Hermes further:

  • Connect more apps: Calendar, Slack, Notion, Linear, and hundreds of others are available through the same Composio Connect setup. Each new integration compounds what Hermes can do for you.
  • Build workflows across tools: Once multiple apps are connected, Hermes can chain actions together — turn an email into a calendar invite, a Slack message into a Linear ticket, or a meeting note into a follow-up draft.
  • Let it learn your patterns: The more you use Hermes, the better it gets at anticipating how you'd handle recurring tasks. Give it feedback on drafts and decisions, and it will adapt.

If you run into trouble or want to share what you've built, join the community or check out the Docs for deeper configuration options.

How to build Brex MCP Agent with another framework

FAQ

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

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.

Can I use Tool Router MCP with Hermes?

Yes, you can. Hermes 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.

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

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.

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 Brex data and credentials are handled as safely as possible.

Used by agents from

Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai
Context
Letta
glean
HubSpot
Agent.ai
Altera
DataStax
Entelligence
Rolai

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