Read invoices, expenses and PDFs; create invoices and record expenses in F-sąskaita. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the F-sąskaita connector, then ask in plain words. The AI picks the tools.
For businesses in Lithuania that issue invoices and record expenses in F-sąskaita.
List the finalized invoices, newest first. Open one invoice to see its seller, buyer, lines, totals and share link.
List the invoices, then download the PDF of the one you need. Files over 3 MB are refused.
Read the business profile and the currency codes first. Then create and finalize the invoice. After a network error, list invoices before you retry.
Changes dataRead the invoice, then resend all of its fields with the same invoice number. The PDF is regenerated.
Changes dataReview the expenses and their totals. Then record a new expense with the receipt or supplier invoice file.
Changes dataThe login page asks for your F-sąskaita business API token.
Create it in F-sąskaita under Settings → Integrations → API. The API needs a Premium plan. The token belongs to one business and is shown only once. It is used only to call the API on your behalf and to derive a private account id.
Team and Enterprise: an Owner adds the connector for the organization first.
No Add custom MCP server option? It depends on your account or workspace settings: see OpenAI's guide.
Run this command, then run /mcp in Claude Code to log in:
Add to Cursor or add this to ~/.cursor/mcp.json:
{
"mcpServers": {
"f-saskaita": {
"url": "https://f-saskaita.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"f-saskaita": {
"type": "http",
"url": "https://f-saskaita.usefulapi.io/mcp"
}
}
} Run these commands. The second one opens the login page:
Windsurf, Cline, Zed and other MCP clients: add this URL as a remote MCP server (Streamable HTTP). The client then opens the login page in your browser.
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 F-sąskaita business API 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.
| 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 F-sąskaita server only. Subscribe with fsaskaita_upgrade (it returns a Stripe Checkout link). Cancel any time with fsaskaita_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running fsaskaita_upgrade before then undoes the cancel. Or write to [email protected].
fsaskaita_get_profilefsaskaita_list_currenciesfsaskaita_list_invoicesfsaskaita_get_invoicefsaskaita_download_invoice_pdffsaskaita_list_expensesfsaskaita_get_expensefsaskaita_download_expense_filefsaskaita_create_invoicefsaskaita_update_invoicefsaskaita_create_expensefsaskaita_update_expensefsaskaita_usage_statusfsaskaita_request_featurefsaskaita_upgradefsaskaita_cancel_subscriptionReview recent invoices and their totals. Download an invoice PDF for a client. Create a new invoice with its lines. Correct an invoice without renumbering it. Record an expense with its receipt. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by F-sąskaita. The server calls the F-sąskaita API with your own F-sąskaita 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 F-sąskaita business API 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 F-sąskaita business API 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 F-sąskaita 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 F-sąskaita.
Yes, if you approve it. 4 of the 12 F-sąskaita tools can create or change data. The other 8 are marked read-only. Most MCP clients ask you to approve a tool call before it runs.
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 F-sąskaita server only. Cancel any time: Pro then runs to the end of the paid period. Run fsaskaita_usage_status to see how many calls you used.
Ask the AI to run fsaskaita_upgrade: it returns a Stripe Checkout link. To cancel, run fsaskaita_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 fsaskaita_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.