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Billsby for AI agents

Billsby is subscription billing software that manages customers, plans, invoices, and usage-based charges, used by SaaS companies to run recurring billing without building it themselves. 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 BillsbySee the 10 actions ↓
Finance and accountingAPI keyMCP + RESTbillsby.com
AUDIT LOG · BILLSBYPOLICY: acme-support
09:41:07 · claude · u_8f2read
billsby.list_products
List Products✓ allowed · 212ms
09:41:08 · claude · u_8f2read
billsby.get_customer
Get Customer✓ allowed · 164ms
09:41:09 · claude · u_8f2write
billsby.create_customer
Create Customer✓ approved · approved by user
EVERY BILLSBY CALL, ON THE RECORD
01 · USE CASES

What agents do in Billsby.

01

Look up a customer's subscription

Get a customer's active subscriptions and shipping address to answer a billing support question.

02

List plans before an upgrade

List product plans to confirm which options are available before suggesting an upgrade to a customer.

03

Update customer details carefully

Update a customer's contact information only after they confirm the new details are correct.

02 · ACTIONS

10 Billsby actions, graded by risk.

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

read

8

Look things up. Allowed by default.

  • billsby.get_customer
    Get Customer
  • billsby.list_products
    List Products
  • billsby.list_customers
    List Customers
  • billsby.get_subscription
    Get Subscription
  • billsby.list_product_plans
    List Product Plans
  • billsby.list_subscriptions
    List Subscriptions
  • billsby.list_customer_subscriptions
    List Customer Subscriptions
  • billsby.get_subscription_shipping_address
    Get Subscription Shipping Address

write

2

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

  • billsby.create_customer
    Create Customer
  • billsby.update_customer
    Update Customer

destructive

0

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

  • No destructive actions.
03 · HOW IT WORKS

Billsby in three steps.

  1. 01Your users connect BillsbyThey add their Billsby api key on Arc0 Connect, under your brand. It goes straight into the vault.
  2. 02You set the rulesReads run, and writes like “create Customer” can wait for the user to approve.
  3. 03Any agent can actYour agent calls Billsby 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('billsby', {
  read: 'allow',
  write: 'ask',        // create_customer
  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 Billsby connects.

Users add their Billsby api key on Arc0 Connect. It is encrypted in the vault, never shown to the model, and each user can rotate or revoke it at any time.

The same Billsby 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
CREDENTIALS
Per-tenant encrypted vault
MODEL SEES
Results only, never credentials
AUDIT LOG
Every call, on every plan
05 · WORKS WITH

Use Billsby 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 actions44API4 actionsAirwallex7 actionsAiwyn Tax10 actionsAltoviz67 actionsCoupa384 actionsZoho Books265 actionsMaxio177 actions
ALL FINANCE AND ACCOUNTING APPS →
07 · FAQ

Billsby and Arc0, answered.

Q01

Can I use Billsby with Claude, ChatGPT or Cursor?

Yes. Connect Billsby 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 Billsby actions you allow.

Q02

How do users connect Billsby?

Users add their Billsby api key on Arc0 Connect. It is encrypted in the vault, never shown to the model, and each user can rotate or revoke it at any time.

Q03

Which Billsby actions can my agent take?

10 in total: 8 read, 2 write and 0 destructive, such as “create Customer”. Your policies decide which of them each agent may call.

Q04

Can I make my agent read-only in Billsby?

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

Q05

Can my own backend call Billsby too?

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

Get started

Plug Billsby into your agent.

Your users connect Billsby once, under your brand. Your agent gets 10 actions behind your policies, with every call on the record.

Connect BillsbyBrowse all apps →

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