Read clients, invoices, expenses, bank transactions and time entries in billey. For freelancers and small companies that keep their books in billey and want an AI assistant to read them. Hosted by usefulapi — connect from Claude, ChatGPT, Cursor, or any MCP client.
Team and Enterprise: an Owner adds the connector for the organization first.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"billey": {
"url": "https://billey.usefulapi.io/mcp"
}
}
}Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"billey": {
"type": "http",
"url": "https://billey.usefulapi.io/mcp"
}
}
}No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run these commands. The second one opens the login page:
Other MCP clients (Windsurf, Cline, Zed and more): add the URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser. Do not add an Authorization header: see Before you connect.
List invoices with their status and dates. Open one invoice for its client summary and line items.
billey_list_invoices billey_get_invoice
List expenses with amounts, dates, the vendor summary and the account. Read the vendors for their contact and payment details.
billey_list_expenses billey_list_vendors
List imported bank transactions with amount, counterparty and match state.
billey_list_bank_transactions
List the projects, then list the time entries with their hours, hourly rate and date.
billey_list_projects billey_list_time_entries
List clients in pages, and use updated_after to read only changes. Open one client for its contact and payment details.
billey_list_clients billey_get_client
The login page asks for your billey personal access token.
Create it in billey → your book's Settings → API tokens (two-factor authentication must be on). Grant clients:read and the reads you need. The token is shown once. It is used only to call the API for you and to derive a private account id.
Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your billey personal access token. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
Turn on the billey connector, then ask in plain words. The AI picks the tools.
| Tool | Type | What it does |
|---|---|---|
billey_list_clients | read | List clients List the clients of the book (name, contact, payment terms, collection method). Returns cursor pagination: follow links.next. Use updated_after to sync only changes. billey API: GET /api/v1/clients. |
billey_get_client | read | Get a client Get one client by id, with its contact and payment details. billey API: GET /api/v1/clients/{client}. |
billey_list_invoices | read | List invoices List invoices with status, dates, totals (decimal strings), the client summary and line items. Filter with updated_after for changes since a time. Returns cursor pagination. billey API: GET /api/v1/invoices. |
billey_get_invoice | read | Get an invoice Get one invoice by id, with its client summary and line items. billey API: GET /api/v1/invoices/{invoice}. |
billey_list_quotes | read | List quotes List quotes (offers) with status, dates, totals and line items. Returns cursor pagination. billey API: GET /api/v1/quotes (needs the quotes:read ability). |
billey_list_expenses | read | List expenses List expenses (purchase costs) with amounts, dates, the vendor summary and the account. Returns cursor pagination. billey API: GET /api/v1/expenses. |
billey_list_vendors | read | List vendors List vendors (suppliers) with their contact and payment details. Returns cursor pagination. billey API: GET /api/v1/vendors. |
billey_list_bank_transactions | read | List bank transactions List imported bank transactions (amount, executed date, counterparty, match and allocation state). Returns cursor pagination. billey API: GET /api/v1/bank-transactions (needs transactions:read). |
billey_list_products | read | List products List products and services from the book's catalogue (unit price, VAT percentage, SKU). Returns cursor pagination. billey API: GET /api/v1/products (needs products:read). |
billey_list_projects | read | List projects List projects with their client summary. Returns cursor pagination. billey API: GET /api/v1/projects (needs projects:read). |
billey_list_time_entries | read | List time entries List logged time entries (hours and hourly rate as decimal strings, date, project). Returns cursor pagination. billey API: GET /api/v1/time-entries (needs time-entries:read). |
billey_usage_status | Usage status (free-tier meter) Report the caller's current usage: the plan, calls used this month, the limit of the plan (the free monthly cap or the Pro fair use limit), remaining, and whether the limit is reached. Read-only; does not count against the meter. | |
billey_request_feature | Request a missing feature Tell usefulapi that the user needs something the billey tools cannot do yet (a missing tool, field or filter). Call it only when the user asks for something none of the tools can do, and tell the user that you send the request. Do not call it for errors or for normal requests. Do not include personal data, credentials or customer records. Stored with the product name and the client type (for example Claude or Cursor), without the user's account. At most 5 requests per day. Does not count against the meter. | |
billey_upgrade | Upgrade to Pro (unlimited*) Get Pro: unlimited tool calls (fair use limit: 10,000 a month) on billey (the free tier caps monthly usage). Plans: "monthly" — $9/month; "yearly" — $90/year (2 months free). Cancel any time: Pro then runs to the end of the paid period, so it also suits a one-time job. *A fair use limit applies. For heavy use (near Pro's limit): "plus" or "plus_yearly" — Pro+, $39/month or $390/year, unlimited tool calls (fair use limit: 100,000 a month); an existing Pro subscription changes to Pro+ in place (needs confirm: true; the price difference for the rest of the period is charged at once). Otherwise returns a short link to open in your browser (it opens Stripe Checkout); after payment the account upgrades automatically. Does not count against the meter. | |
billey_cancel_subscription | Cancel the Pro subscription Cancel the caller's billey Pro subscription at the end of the paid period (no refund for the current period; Pro continues until then, then the free tier applies). Requires confirm: true. Run billey_upgrade later to undo the cancel before the period ends. Does not count against the meter. |
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Proper user | $9/mo · $90/yr | Unlimited* |
*Pro fair use limit: 10,000 tool calls a month on this server. For more, write to [email protected].
Pro covers this billey server only. Subscribe with billey_upgrade (it returns a Stripe Checkout link). Cancel any time with billey_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running billey_upgrade before then undoes the cancel. Or write to [email protected].
Review invoices and their line items. Review expenses and their vendors. Find bank transactions to match. Check the hours logged on a project. Sync client changes into another tool. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by billey. The server calls the billey API with your own billey access, so it sees only the data that your account can see.
Yes. In Claude, add this server's URL as a custom connector. In ChatGPT, add it as a custom MCP server in Plugins. Then log in once. Cursor, VS Code, Claude Code and Codex work too. See the setup steps.
The login page asks for your billey personal access token. See Before you connect for where to find it.
No. Add only the URL. Do not add an Authorization header or an API key to the client config. The server signs you in with OAuth: the login page asks for your billey personal access token. If the config has such a header, remove it: some clients then send that header instead of the login token, and every call fails with 401.
The login stores them encrypted in the authorization grant of your connection. The server uses them to call the billey API for you and to derive a private account id for usage metering. usefulapi does not show them on any page or in any reply. To stop all access, remove the connector and change or delete these credentials in billey.
All 11 billey tools are marked read-only.
The Free plan gives 50 tool calls / month. Pro costs $9/mo or $90/yr, with unlimited tool calls (fair use limit: 10,000 tool calls a month), for this billey server only. Cancel any time: Pro then runs to the end of the paid period. Run billey_usage_status to see how many calls you used.
Ask the AI to run billey_upgrade: it returns a Stripe Checkout link. To cancel, run billey_cancel_subscription. Pro continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with billey_request_feature. We store the text with the server name, the type of AI client and the tool you tried, not with your account, and read every request when we plan new tools. You can send up to 5 requests per day.
Any client that supports remote MCP servers (Streamable HTTP) with OAuth login: Claude (web and desktop), Claude Code, ChatGPT, Codex, Cursor, VS Code, Windsurf and others.
This is a Model Context Protocol endpoint — meant to be connected from an AI client, not opened in a browser. An invalid_token response at the URL is the auth gate working as designed; clients authenticate automatically.
Need a tool this server does not have, or a connection to another system? We build custom integrations and MCP servers.