Look up customers, invoices, products and subscriptions in WeFact. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the WeFact connector, then ask in plain words. The AI picks the tools.
For Dutch and Belgian entrepreneurs and accountants who send invoices from WeFact.
List invoices by status or date range. Open one to read its lines, paid amount and outstanding amount.
List customers with a search term or customer group. Open one for its address, VAT number and contacts.
List products and services with their price excluding VAT and VAT rate. Open one for its description and price period.
List the recurring subscriptions, active by default, with customer, product, price and next invoice date.
The login page asks for your WeFact API key.
Find it in WeFact → Settings → API. The API must be switched on there. If you use the API whitelist, the usefulapi servers must be allowed, or remove the whitelist. Your key is used only to call the API on your behalf and to derive a private account id; it is never shown to anyone.
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": {
"wefact": {
"url": "https://wefact.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"wefact": {
"type": "http",
"url": "https://wefact.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 WeFact API 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.
| 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 WeFact server only. Subscribe with wefact_upgrade (it returns a Stripe Checkout link). Cancel any time with wefact_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running wefact_upgrade before then undoes the cancel. Or write to [email protected].
wefact_list_debtorswefact_get_debtorwefact_list_invoiceswefact_get_invoicewefact_list_productswefact_get_productwefact_list_subscriptionswefact_usage_statuswefact_request_featurewefact_upgradewefact_cancel_subscriptionFind unpaid invoices and the amount outstanding. Look up a customer and their details. Check products and their VAT rates. Review active subscriptions and next invoice dates. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by WeFact. The server calls the WeFact API with your own WeFact 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 WeFact API 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 WeFact API 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 WeFact 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 WeFact.
All 7 WeFact 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 WeFact server only. Cancel any time: Pro then runs to the end of the paid period. Run wefact_usage_status to see how many calls you used.
Ask the AI to run wefact_upgrade: it returns a Stripe Checkout link. To cancel, run wefact_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 wefact_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.