Read and update articles, customers and stock in KASSA.AT. Hosted by usefulapi: connect it to Claude, ChatGPT, Cursor or any MCP client.
Turn on the KASSA.AT connector, then ask in plain words. The AI picks the tools.
For Austrian shops and businesses that run a KASSA.AT cash register.
Search the articles by text, article number or bar code. Each article shows its price, VAT percent and unit. Then list the categories an article belongs to.
Find one customer by the number you assigned, or search all customers with a text query.
List the warehouses, then read the current stock of an article in one of them. Inventory lookups are rate limited by KASSA.AT.
Find the inventory record of an article in a warehouse, then record a stock movement. A positive quantity adds stock and a negative one removes it.
Changes dataCreate an article with a VAT percent of 0, 10, 13 or 20, or change fields of an article or customer. Nothing is deleted.
Changes dataThe login page asks for your KASSA.AT company subdomain and KASSA.AT API token.
The subdomain is the part before .kassa.at in your KASSA.AT address. Your token 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": {
"kassa-at": {
"url": "https://kassa-at.usefulapi.io/mcp"
}
}
} Add to VS Code or add this to .vscode/mcp.json:
{
"servers": {
"kassa-at": {
"type": "http",
"url": "https://kassa-at.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 KASSA.AT company subdomain and KASSA.AT 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 | 10,000 tool calls / month |
| Pro+per user | $39/mo · $390/yr | 100,000 tool calls / month |
Each paid plan covers this KASSA.AT server only. Ask your AI to run kassa_upgrade and choose Pro or Pro+, billed monthly or yearly (it returns a Stripe Checkout link). If you already have Pro, ask to change it to Pro+. The change requires your confirmation, keeps your billing interval and charges the price difference for the rest of the period immediately. Cancel any time with kassa_cancel_subscription: your paid plan continues to the end of the paid period, with no refund for the current period, and asking to resume the same plan with kassa_upgrade before then undoes the cancel. Or write to [email protected].
kassa_list_articleskassa_list_article_categorieskassa_list_customerskassa_find_customer_by_numberkassa_list_warehouseskassa_list_inventorieskassa_get_inventory_stockkassa_create_articlekassa_update_articlekassa_create_customerkassa_update_customerkassa_record_stock_movementkassa_usage_statuskassa_request_featurekassa_upgradekassa_cancel_subscriptionLook up articles with prices and VAT. Find a customer by customer number. Check the stock of an article in a warehouse. Add received goods to stock. Create or update articles and customers. See what you can do for the details.
No. usefulapi is an independent service. It is not affiliated with or endorsed by KASSA.AT. The server calls the KASSA.AT API with your own KASSA.AT 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 KASSA.AT company subdomain and KASSA.AT API token. See Before you connect for where to find them.
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 KASSA.AT company subdomain and KASSA.AT 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 KASSA.AT 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 KASSA.AT.
Yes, if you approve it. 5 of the 12 KASSA.AT tools can create or change data. The other 7 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 10,000 tool calls / month. Pro+ costs $39/mo or $390/yr, with 100,000 tool calls / month. Each subscription covers this KASSA.AT server only. Cancel any time: your paid plan then runs to the end of the paid period. Run kassa_usage_status to see how many calls you used.
Ask the AI to run kassa_upgrade and choose Pro or Pro+, billed monthly or yearly: it returns a Stripe Checkout link. If you already have Pro, ask to change it to Pro+. After you confirm, your existing subscription changes in place, keeps its billing interval and charges the price difference for the rest of the period immediately. To cancel, run kassa_cancel_subscription. Your paid plan continues to the end of the paid period.
Tell the AI what you wanted to do. It can send the request with kassa_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.