Mercury for AI agents

Mercury is business banking software, used here only for read-only lookups of accounts, balances, transactions, cards, recipients, and statements, with no ability to move money. 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 Mercury See the 30 actions ↓

Finance and accountingOAuth 2.0 (MCP)MCP + RESTmercury.com

AUDIT LOG · MERCURYPOLICY: acme-support

09:41:07 · claude · u_8f2read

mercury.list_credit

Listcredit✓ allowed · 212ms

09:41:08 · claude · u_8f2read

mercury.get_user

Getuser✓ allowed · 164ms

EVERY MERCURY CALL, ON THE RECORD

01 · USE CASES

What agents do in Mercury.

Check an account's balance

Look up a business account's current balance before answering a cash-flow question.

Pull recent transactions

List recent transactions on an account to reconcile spend, a read-only view since Mercury blocks all writes here.

Review a pending money-movement request

Check the status of a pending send-money approval request without approving or changing it.

02 · ACTIONS

30 Mercury actions, graded by risk.

Every Mercury 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.

mercury.get_user
Getuser
mercury.get_users
Getusers
mercury.get_account
Getaccount
mercury.get_invoice
Getinvoice
mercury.get_webhook
Getwebhook
mercury.list_credit
Listcredit
mercury.get_accounts
Getaccounts
mercury.get_customer
Getcustomer
mercury.get_treasury
Gettreasury
mercury.get_webhooks
Getwebhooks
mercury.get_recipient
Getrecipient
mercury.list_invoices
Listinvoices
mercury.get_attachment
Getattachment
mercury.get_recipients
Getrecipients
mercury.list_customers
Listcustomers
mercury.get_transaction
Gettransaction

+ 14 MORE

write

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

No write actions.

destructive

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

No destructive actions.

03 · HOW IT WORKS

Mercury in three steps.

01Your users connect MercuryThey sign in to Mercury on Arc0 Connect, under your brand, and approve the access you ask for.
02You set the rulesReads run, and writes like “updates” can wait for the user to approve.
03Any agent can actYour agent calls Mercury 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('mercury', {
  read: 'allow',
  write: 'ask',        
  destructive: 'deny',  
})

# 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 Mercury connects.

Mercury runs its own MCP server behind OAuth. Arc0 registers the client, users approve access on Arc0 Connect, and your agent reaches Mercury through the same endpoint, policies and audit log as every other app.

The same Mercury 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: OAuth 2.0 (MCP)
CREDENTIALS: Per-tenant encrypted vault
MODEL SEES: Results only, never credentials
AUDIT LOG: Every call, on every plan

05 · WORKS WITH

Use Mercury 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

Mercury and Arc0, answered.

Q01

Can I use Mercury with Claude, ChatGPT or Cursor?

Yes. Connect Mercury 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 Mercury actions you allow.

Q02

How do users connect Mercury?

Q03

Which Mercury actions can my agent take?

30 in total: 30 read, 0 write and 0 destructive. Your policies decide which of them each agent may call.

Q04

Can I make my agent read-only in Mercury?

Yes. Allow read actions and deny writes in the Mercury policy. Your agent can still look things up, and any write it attempts is blocked and logged.

Q05

Can my own backend call Mercury too?

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

Get started

Plug Mercury into your agent.

Your users connect Mercury once, under your brand. Your agent gets 30 actions behind your policies, with every call on the record.

Connect Mercury Browse all apps →

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