Billy
Read and manage invoices, bills, contacts and products in your Billy accounting account.
Connect to Billy accounting software to view invoices, bills, bank statements and ledger postings. Create new contacts and draft invoices for review. Requires a Billy account and API access.
Try asking Muse: "Show me all unpaid invoices from the last 30 days and create a draft invoice for a new customer."
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Source: Found in the official MCP Registry (io.usefulapi/billy) · First listed October 28, 2026
Last 24 hours
Each bar is one check, every 15 minutes. Green means it answered. Last checked 6 min ago.
Is it safe to connect?
What Muse can see: It does not ask you to sign in, so it cannot see your accounts. It only sees what Muse sends it from your request.
Before it acts: Read what Muse plans to do before you approve it, and remove the app from Muse when you stop using it.
musedirectory.ai is not part of Meta. More about how Muse handles your information
How to add it to Muse
Not in Muse's Connectors list yet, but Muse can still use it. Copy the request below and paste it into Muse. Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
https://billy.usefulapi.io/mcpNot in Muse's Connectors list yet. Muse can still use it: its page gives you a request to paste into Muse.
Also use it in ChatGPT or Claude
Billy is a remote MCP server, so any assistant that can add a custom connector by link can use it. Same link, same tools.
Add it to ChatGPT
- 1
Open ChatGPT settings
In ChatGPT, open Settings, then Connectors (called Apps & Connectors on some accounts).
- 2
Turn on developer mode
Under Advanced settings, switch on Developer mode. That is what lets you add a connector by link.
- 3
Create the connector
Choose Create, give it a name, paste the link as the MCP server URL, and save. If it needs a sign-in, ChatGPT asks for it here.
- 4
Use it in a chat
Start a chat, open the tools menu, pick the connector, and ask. ChatGPT asks before it runs a tool the first time.
Custom connectors need a paid ChatGPT plan, and on Team, Enterprise and Edu accounts only an admin can add them. Our "Working" label means the server answered us; it cannot tell whether your plan lets you add it. All connectors that work in ChatGPT
Add it to Claude
- 1
Open Claude settings
In Claude, open Settings, then Connectors.
- 2
Add a custom connector
Choose Add custom connector, give it a name, and paste the link.
- 3
Connect and use it
If it needs a sign-in, Claude sends you to it. Then turn the connector on in a chat from the tools menu and ask.
Custom connectors are available on paid Claude plans; on Team and Enterprise accounts an admin may need to add them. Our "Working" label means the server answered us; it cannot tell whether your plan lets you add it. All connectors that work in Claude
https://billy.usefulapi.io/mcpWhat people ask Muse to do
Technical details: safety screening, tools, response time and recent checks
Response time at the last check: 157ms. Worked in 100% of checks over 30 days.
Screening · October 29, 2026
Screened, no issues found
Screening looks for known threats and hidden instructions at the time of the check, and runs again weekly and whenever the tool list changes. It cannot see the server's code, so only connect what you need and review what Muse asks to do. How screening works.
Tools · 15
billy_get_organizationThe Billy company the access token belongs to: id, name, address, registration (CVR) number, base currency, VAT settings, fiscal year, default payment terms, invoice numbering, default accounts. Good first call. GET /organization.billy_list_contactsList customers and suppliers: name, type, address, CVR/registration number, EAN, payment terms, customer/supplier flags. The API has no documented search filter, so `search` is applied to the returned page only (case-insensitive on name, contact number and registration number); pbilly_get_contactOne contact by id, with its contact persons (names and e-mail addresses). GET /contacts/{id}.billy_list_invoicesList sales invoices and credit notes (newest first by default): number, date, due date, state (draft/approved/voided), amount, tax, balance, isPaid, contactId, currency. Filter by state, customer, number, date, period, paid status or free text. Paged. GET /invoices.billy_get_invoiceOne invoice by id with its lines (product, description, quantity, unit price, amount, tax) and its payment associations. GET /invoices/{id}.billy_list_billsList bills (purchase invoices from suppliers): supplier, dates, state (draft/approved/voided), amount, balance, isPaid, supplier invoice number. Filter by state, supplier, dates or paid status. Paged. GET /bills.billy_get_billOne supplier bill by id with its lines. GET /bills/{id}.billy_list_productsList products and services usable as invoice lines: name, product number, description, sales account, archived flag. The API has no documented search filter, so `search` is applied to the returned page only (name, productNo). Paged. GET /products.billy_get_productOne product by id with its unit prices per currency. GET /products/{id}.billy_list_accountsThe chart of accounts: account number, name, group, nature, VAT rate, bank-account flag and bank details (IBAN, bank name) of bank accounts. With is_bank_account=true this lists the bank accounts whose ids billy_list_bank_lines needs. Paged. GET /accounts.billy_list_tax_ratesThe company's VAT rates: name, rate (as a fraction, 0.25 = 25 percent), whether it applies to sales or purchases, active flag. Paged. GET /taxRates.billy_list_bank_linesList the bank-statement lines of ONE bank account (read only; nothing is matched or reconciled): date, description, amount, side (debit/credit), reconciled flag, receipt state. Get the account id from billy_list_accounts with is_bank_account=true. Paged. GET /bankLines.billy_list_postingsList ledger postings (the bookkeeping entries): date, text, account, amount, side (debit/credit), currency, voided flag. Filter by account, date or period. Read only. Paged. GET /postings.billy_create_contactWRITE: create ONE new contact (customer and/or supplier) in the company's Billy account. It does not check for duplicates (call billy_list_contacts first) and nothing is sent to the contact. Not idempotent: a repeat call creates a second contact. POST /contacts.billy_create_draft_invoiceWRITE: create ONE invoice in the DRAFT state for an existing contact. The invoice is NOT approved, booked, numbered into the ledger or sent: the user reviews it in Billy and approves and sends it there. The invoice number is assigned by Billy. No payment is created. Not idempotenRecent checks
Link
https://billy.usefulapi.io/mcpQuestions about Billy in Muse
How do I connect Billy to Muse?
Not in Muse's Connectors list yet, but Muse can still use it. Paste this into Muse: "Use Billy to help me. It is a free service with an MCP server at https://billy.usefulapi.io/mcp. It does not need an API key. Ask me before you share anything with it." Muse asks before it shares anything with the app's site. Meta does not review apps used this way, so only use ones you trust. We tested this in the Muse app on September 24, 2026: Muse used an app's link directly this way and returned a live answer.
Is Billy working right now?
At the last check (October 29, 2026, 11:45 UTC) the endpoint was working, answering in 157ms. Over the last 7 days it answered 100% of health checks. It is checked every 15 minutes.
Is Billy safe to connect to Muse?
It was screened on October 29, 2026 with the result "screened, no issues found". Screening checks the domain against threat feeds and reads the tools for hidden instructions and requests for passwords or card numbers. It cannot see the server's code, so grant only the access you need.
What can Billy do in Muse?
It exposes 15 tools, including billy_get_organization, billy_list_contacts, billy_get_contact, billy_list_invoices. For example, you could ask Muse: "Show me all unpaid invoices from the last 30 days and create a draft invoice for a new customer."
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This listing was added from public sources (Found in the official MCP Registry (io.usefulapi/billy)). If you build Billy, claim it to correct the details and get your badge.
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