Read Yuki administrations, open invoices, ledger balances, contacts and documents. For accountants and businesses that keep their books in Yuki and want quick answers from their administration. 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": {
"yuki": {
"url": "https://yuki.usefulapi.io/mcp"
}
}
}Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"yuki": {
"type": "http",
"url": "https://yuki.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.
The AI lists unpaid sales invoices with amounts and due dates, within a date range if you like, and finds the contact behind each one.
yuki_list_outstanding_debtor_items yuki_search_contacts
The AI lists the purchase invoices you still have to pay, with amounts, references and due dates, so you can plan payments.
yuki_list_outstanding_creditor_items
The AI reads the chart of accounts, the balance of every ledger account on a date, and the transactions booked on one account.
yuki_get_gl_account_scheme yuki_get_gl_account_balance yuki_list_gl_account_transactions
The AI gives the net revenue of an administration in a date range, and lists the administrations a key reaches, which suits accountants.
yuki_get_net_revenue yuki_list_administrations
The AI searches the document archive for invoices, receipts and statements, shows the details and gives a short-lived download link.
yuki_search_documents yuki_get_document yuki_get_document_download_url
The login page asks for your Yuki web service access key.
In Yuki open Settings → Integrations → Web services and choose Add new API key (needs the Management or Backoffice role; the key can be limited to one administration). Copy the key. It is used only to read your Yuki data on your behalf; revoke it in Yuki at any time.
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 Yuki web service access key. 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 Yuki connector, then ask in plain words. The AI picks the tools.
| Tool | Type | What it does |
|---|---|---|
yuki_list_domains | read | List domains List the Yuki domains (customer environments) this access key can reach: id, name and URL. Accountant keys reach many domains. Accounting.Domains. |
yuki_list_administrations | read | List administrations List the administrations (companies with their own books) this access key can reach: id, name, address, Chamber of Commerce and VAT numbers, start date. Use the ids in the other tools. Accounting.Administrations. |
yuki_list_outstanding_debtor_items | read | List open sales invoices (debtors) Open items on the debtors list (unpaid sales invoices): date, description, contact, open and original amount, reference, due date. Optionally within a date range. Accounting.OutstandingDebtorItems / OutstandingDebtorItemsByDate. |
yuki_list_outstanding_creditor_items | read | List open purchase invoices (creditors) Open items on the creditors list (unpaid purchase invoices): date, description, contact, open and original amount, reference, due date. Optionally within a date range. Accounting.OutstandingCreditorItems / OutstandingCreditorItemsByDate. |
yuki_get_gl_account_balance | read | Get general ledger balances The balance of every general ledger account of an administration on a date (yyyy-mm-dd): account code, description, amount. Accounting.GLAccountBalance. |
yuki_list_gl_account_transactions | read | List general ledger transactions The transactions booked on one general ledger account in a date range: date, description, amount, contact, project. Get account codes from yuki_get_gl_account_scheme. Accounting.GLAccountTransactions. |
yuki_get_net_revenue | read | Get net revenue The net revenue (turnover) of an administration in a date range, by transaction date. Accounting.NetRevenue. |
yuki_get_gl_account_scheme | read | Get chart of accounts The general ledger accounts (chart of accounts) of an administration: code, description, type. Use the codes in yuki_list_gl_account_transactions. AccountingInfo.GetGLAccountScheme. |
yuki_list_projects | read | List projects Projects of an administration (code, description, company, contact, period, budgets), optionally filtered. AccountingInfo.GetProjects. |
yuki_search_contacts | read | Search contacts Search the contacts (customers and suppliers) of a domain by name, city, postcode, tag, email, website, phone, code, Chamber of Commerce number, VAT number or bank account. Returns at most 100 contacts per page; ask for the next page_number until the reply is empty. Contact.SearchContacts. |
yuki_list_document_folders | read | List archive folders The folders of the document archive (id, name). With an accountant key that reaches several domains, pass domain_id so the archive of that domain is read (default: the key's only domain). Archive.DocumentFolders. |
yuki_list_document_folder_tabs | read | List archive folder tabs The tabs inside one archive folder (id, name). Archive.DocumentFolderTabs. |
yuki_list_documents | read | List archive documents Documents in the archive (invoices, receipts, bank statements...) with id, subject, type, contact, dates, amount. Narrow by archive folder or by document type, and by creation date range. Page with number_of_records and start_record. Archive.Documents / DocumentsInFolder / DocumentsByType. |
yuki_search_documents | read | Search archive documents Search archive documents by text in the creator, contact, subject, tag or type (or all). Optionally limit to a folder or tab and a date range. Archive.SearchDocuments. |
yuki_get_document | read | Get document Details of one archive document by id (subject, type, contact, dates, amounts, folder). Archive.FindDocument. |
yuki_get_document_download_url | read | Get document download link A presigned download URL for the file of one archive document (the link works for a short time; open it in a browser). Archive.DocumentDownloadUrl. |
yuki_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. | |
yuki_request_feature | Request a missing feature Tell usefulapi that the user needs something the Yuki 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. | |
yuki_upgrade | Upgrade to Pro (unlimited*) Get Pro: unlimited tool calls (fair use limit: 10,000 a month) on Yuki (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. | |
yuki_cancel_subscription | Cancel the Pro subscription Cancel the caller's Yuki 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 yuki_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 account | $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 Yuki server only. Subscribe with yuki_upgrade (it returns a Stripe Checkout link). Cancel any time with yuki_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running yuki_upgrade before then undoes the cancel. Or write to [email protected].
Chase open sales invoices. Review open purchase invoices. Check ledger balances. Report net revenue. Find archived documents. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by Yuki. The server calls the Yuki API with your own Yuki 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 Yuki web service access key. 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 Yuki web service access key. 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 Yuki 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 Yuki.
All 16 Yuki 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 Yuki server only. Cancel any time: Pro then runs to the end of the paid period. Run yuki_usage_status to see how many calls you used.
Ask the AI to run yuki_upgrade: it returns a Stripe Checkout link. To cancel, run yuki_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 yuki_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.