Brex for AI agents

Brex provides corporate credit cards and spend management tools that finance teams use to track transactions, manage budgets, and process employee expenses. Connect it once through Arc0, and your agent, or Claude, ChatGPT and Cursor, can use it through one MCP endpoint, limited to what each user approved.

Connect Brex See the 84 actions ↓

Finance and accountingOAuth 2.0MCP + RESTbrex.com

AUDIT LOG · BREXPOLICY: acme-support

09:41:07 · claude · u_8f2read

brex.list_cards

List Cards✓ allowed · 212ms

09:41:08 · claude · u_8f2read

brex.list_trips

List Trips✓ allowed · 164ms

09:41:09 · claude · u_8f2write

brex.create_card

Create Card✓ approved · approved by user

09:41:12 · claude · u_8f2destructive

brex.delete_field

Delete Field✕ blocked · policy: deny

EVERY BREX CALL, ON THE RECORD

01 · USE CASES

What agents do in Brex.

Look up card transactions

Read-only pull of a card's recent transactions and expense details before reconciling spend for the month.

Create an expense record

Create an expense entry for a transaction after the user confirms the category and vendor.

Require approval before archiving a budget

Treat archiving a budget or spend limit as needing confirmation since it affects what employees can spend.

02 · ACTIONS

84 Brex actions, graded by risk.

Every Brex action is tagged read, write or destructive, so one policy covers the whole app and new actions inherit the right default.

read

Look things up. Allowed by default.

brex.list_cards
List Cards
brex.list_trips
List Trips
brex.list_users
List Users
brex.get_expense
Get Expense
brex.list_titles
List Job Titles
brex.get_referral
Get Referral By ID
brex.list_budgets
List Budgets
brex.list_vendors
List Vendors
brex.list_expenses
List Expenses
brex.get_user_limit
Get User Limit
brex.list_locations
List Locations
brex.list_referrals
List Referrals
brex.list_transfers
List Transfers
brex.get_card_number
Get Card Number
brex.get_field_by_id
Get Field By ID
brex.get_title_by_id
Get Title by ID

+ 31 MORE

write

Create and change things. Allow, or ask the user first.

brex.create_card
Create Card
brex.create_user
Create User
brex.update_user
Update User
brex.create_field
Create Custom Field
brex.create_title
Create Job Title
brex.update_field
Update Field
brex.create_budget
Create Budget
brex.create_vendor
Create Vendor
brex.update_budget
Update Budget
brex.update_vendor
Update Vendor
brex.create_expense
Create Expense
brex.update_expense
Update Expense
brex.create_document
Create Document Upload for Referral
brex.create_location
Create Location
brex.create_budget_v1
Create Spend Limit (Budget V1)
brex.update_budget_v1
Update Spend Limit (V1)

+ 16 MORE

destructive

Delete, cancel or archive. Ask first, or deny outright.

brex.delete_field
Delete Field
brex.delete_vendor
Delete Vendor
brex.archive_budget
Archive Budget
brex.archive_spend_limit
Archive Spend Limit
brex.delete_field_values
Delete Field Values

03 · HOW IT WORKS

Brex in three steps.

01Your users connect BrexThey sign in to Brex on Arc0 Connect, under your brand, and approve the access you ask for.
02You set the rulesReads run, writes like “create Card” can wait for the user, and “delete Field” can be denied outright.
03Any agent can actYour agent calls Brex through the Arc0 SDK or MCP, and so can Claude, ChatGPT and Cursor. Every call lands on the audit log.

POLICY.TS

await arc0.policies.set('brex', {
  read: 'allow',
  write: 'ask',        // create_card
  destructive: 'deny',  // delete_field
})

# Claude Code: the same connection, one URL
$ claude mcp add --transport http arc0 \
    https://mcp.arc0.ai/u/u_8f2

04 · AUTH AND DATA

How Brex connects.

Users sign in to Brex on Arc0 Connect and approve the scopes you request. Build with Arc0’s Brex OAuth app, or bring your own so the Brex consent screen names you. Tokens refresh automatically, and you can export them whenever you want.

The same Brex connection serves your agent over MCP and your own backend over REST and the proxy, so a user connects once. How Arc0 handles credentials →

AUTH: API key · OAuth 2.0
CREDENTIALS: Per-tenant encrypted vault
MODEL SEES: Results only, never credentials
AUDIT LOG: Every call, on every plan

05 · WORKS WITH

Use Brex from any agent.

Claude

ChatGPT

Cursor

Codex

VS Code

OpenAI Agents SDK

Claude Agent SDK

Vercel AI SDK

Mastra

LangGraph

06 · RELATED

More finance and accounting apps.

Stripe433 actions 44API4 actions

Zoho Books265 actions

Maxio177 actions

ALL FINANCE AND ACCOUNTING APPS →

07 · FAQ

Brex and Arc0, answered.

Q01

Can I use Brex with Claude, ChatGPT or Cursor?

Yes. Connect Brex to Arc0 once, then add your Arc0 MCP URL to Claude, ChatGPT, Cursor, Claude Code or any other remote-MCP client. Each assistant only gets the Brex actions you allow.

Q02

How do users connect Brex?

Q03

Which Brex actions can my agent take?

84 in total: 47 read, 32 write and 5 destructive, such as “create Card”. Your policies decide which of them each agent may call.

Q04

Can I stop my agent from deleting things in Brex?

Yes. Actions like “delete Field” are graded destructive. Set destructive actions to deny, or to ask so the user approves each one, and blocked calls still show up on the audit log.

Q05

Can my own backend call Brex too?

Yes. The same Brex connection is available over REST and through the Arc0 proxy, so your product and your agent share one connection per user.

Get started

Plug Brex into your agent.

Your users connect Brex once, under your brand. Your agent gets 84 actions behind your policies, with every call on the record.

Connect Brex Browse all apps →

Free to build · MCP + REST · Audit log on every plan