AI agents for Brex
A Monmo AI agent works in Brex the way a finance coordinator who owns month-end would. It chases cardholders for missing receipts and memos, watches spend against each budget, flags charges that look wrong and prepares bills for payment. It uses an account your Brex admin connects, reads without asking, and asks before it pays a bill, issues a card or changes a limit.
Updated 2026-11-13 · Free to start. Paid plans from $15 a month.
What agents do in Brex
Chase missing receipts and memos
Every Friday the agent lists card expenses with no receipt or memo, grouped by cardholder, and drafts a short Slack message to each person naming the merchant, the date and the amount. Sending asks first.
AskEvery Friday at 3, list Brex expenses missing a receipt or memo and draft a Slack reminder to each cardholder.
Find the receipt for an expense
Many receipts already sit in someone's inbox. The agent searches Gmail for the order confirmation that matches each charge by merchant, amount and date, and prepares it to attach. Attaching asks first.
AskFor last week's Brex expenses with no receipt, search my Gmail for matching confirmations and show me what you found.
Watch spend against budgets
Each Monday it compares what each team has spent with its Brex budget for the month and lists the budgets past 80 percent, with the largest charges behind each one.
AskEvery Monday, show me which Brex budgets are over 80 percent for the month and the three biggest charges in each.
Flag charges that look wrong
It looks for the same merchant charging twice in a day, a new vendor with a large first charge, software billed on two different cards, and spend outside the policy you describe, and explains each one.
AskCheck this month's Brex card spend for duplicate charges, the same software on two cards and anything over 500 without a memo.
Prepare bills for payment
From supplier invoices in your inbox it drafts each bill in Brex with the vendor, amount, due date and the purchase it relates to. You approve the payment run; nothing is paid without that card.
AskDraft Brex bills for the four supplier invoices emailed this week and show me the payment run before anything is scheduled.
Get expenses ready for the books
Before close it checks that each expense has a category and department, suggests codes for the ones that do not, and lists what will sync to QuickBooks or NetSuite. Applying the codes asks first.
AskList October's Brex expenses with no category or department and suggest one for each, based on how we coded that merchant before.
Handle a card or limit request
When someone asks in Slack for a new card or a higher limit, it checks their past spend and the budget it would come from and prepares the request. Issuing a card or raising a limit is your call.
AskAlex asked for a 2,000 travel card for the Berlin trip. Check the travel budget and prepare the request for me to approve.
How it connects
- 1A Brex account admin connects Brex once, from your own company account. The agent sees the cards, expenses, budgets and bills that connection may see, and only the last four digits of any card.
- 2You choose which agents may use Brex. Your finance or operations agent needs it; nobody else on the team does.
- 3Reading expenses, budgets and statements needs no approval. Paying a bill, issuing or locking a card, changing a limit or budget, and messaging a cardholder each ask first.
More in Accounting and payments
Other apps of this kind that agents work in, each with its own page.
Questions people ask
Can an AI agent chase employees for Brex receipts?
Yes. A Monmo agent lists the expenses missing a receipt or memo, finds what it can in Gmail itself, and drafts a short reminder to each cardholder. You see every reminder on one card before it goes out in Slack or email, and you can drop anyone from the list.
Can an AI agent pay bills or raise card limits in Brex?
Not without you. The agent prepares the bill or the request and shows the vendor or person, the amount and the reason on its own card. When you allow it, the change is made through the Brex connection, or in its own browser when the connection does not cover something. Declined requests stay undone.
Is it safe to connect Brex to an AI agent?
The agent works through the access your Brex admin gives the connection, so it cannot see or do more than that. It never sees full card numbers. Looking things up needs no approval; anything that moves money or changes a card, limit or budget does. You can watch it work and remove access at any time.
Can it help us close the month faster with Brex?
It takes on the chasing and checking. Before close the agent finds expenses without receipts, memos or codes, suggests categories from your past coding, and lists what is ready to sync to your accounting software. You still review and lock the period; the agent hands you a short list instead of a long one.