# Billy Muse connector

From musedirectory.ai, the independent directory of Meta Muse connectors. Not affiliated with Meta.

## Billy

Read and manage invoices, bills, contacts and products in your Billy accounting account.

- Record: https://musedirectory.ai/connector/billy
- Category: Finance & Bills
- Developer: usefulapi (https://usefulapi.io/billy/)
- Muse status: Extra setup. Not in Muse's Connectors list yet. Muse can still use it: its page gives you a request to paste into Muse.
- Health: Working, 157ms, checked 2026-10-29T11:45:46Z
- Endpoint: https://billy.usefulapi.io/mcp
- Auth: No account needed; Pricing: unknown
- Screening: Screened, no issues found (2026-10-29T12:36:08Z)
- Source: Found in the official MCP Registry (io.usefulapi/billy) https://registry.modelcontextprotocol.io/v0/servers?search=io.usefulapi%2Fbilly

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.

Example request: "Show me all unpaid invoices from the last 30 days and create a draft invoice for a new customer."

How to connect: 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.

Tools:
- billy_get_organization: The 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_contacts: List 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); p
- billy_get_contact: One contact by id, with its contact persons (names and e-mail addresses). GET /contacts/{id}.
- billy_list_invoices: List 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_invoice: One invoice by id with its lines (product, description, quantity, unit price, amount, tax) and its payment associations. GET /invoices/{id}.
- billy_list_bills: List 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_bill: One supplier bill by id with its lines. GET /bills/{id}.
- billy_list_products: List 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_product: One product by id with its unit prices per currency. GET /products/{id}.
- billy_list_accounts: The 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_rates: The 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_lines: List 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_postings: List 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_contact: WRITE: 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_invoice: WRITE: 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 idempoten

Screening checks:
- MCP handshake: pass (Answered in 13ms)
- Domain against threat feeds (Cloudflare security DNS): pass (billy.usefulapi.io, usefulapi.io not flagged)
- Published packages against the OSV malicious-package database: n/a (No npm or PyPI package published)
- Hidden instructions or invisible characters in tool text: pass (15 tools read, nothing found)
- Inputs asking for passwords, card numbers or seed phrases: pass (None found)
- Domain and redirects: pass (No redirects off the domain)
- AI review of purpose and tool behavior: pass (No concerns)