AI assistant
An AI assistant over your payments and documents, via MCP
Zettl is a remote MCP server at https://zettlapp.com/mcp. Add it to an MCP-capable AI assistant such as Claude and ask in your own words: which payments lack a document, what you spent, which invoices are unpaid.
How it works
Add the connector
In the assistant, add a custom connector with the address https://zettlapp.com/mcp.
Sign in and allow
Sign in with your Zettl account (OAuth 2.1) and allow access to one company: read only, or changes too.
Ask
The assistant reads invoices, payments, documents, clients and connected accounts, finds payments without a document and summarizes income and expenses.
Let it work
With changes allowed it can match a document to a payment, undo a match, set a payment's category and change an invoice's status.
Good to know
- The assistant acts with your permissions and sees only the company you granted.
- The assistant never sees bank credentials or the API token.
- Revoke a connection under Settings → Banks & integrations → AI connections; it takes effect immediately.
- The MCP connector is part of the Firma plan (350 Kč a month).
Frequently asked questions
Short answers on this topic.
What is MCP?
The Model Context Protocol, an open standard through which an AI assistant works with another app's data. Zettl offers it as a remote server, so there is nothing to install.
Which assistants does it work with?
With assistants that can connect a remote MCP server with OAuth sign-in, such as Claude.
Can the assistant change anything without my permission?
Only if you tick “Also allow changes” when connecting. Without it the connection is read-only and the assistant does not even see the tools for changes.
Read next
- Matching payments with documentsZettl looks for the receipt or invoice for each Fio banka payment by amount, date and vendor. Whatever is left unmatched, you see at once.
- Monthly files for your accountantZettl shows which payments still lack a document and downloads the month's receipts as one PDF with a summary. The Fio statement as PDF, payments as CSV.
- Fio API for bookkeepingHow to connect Fio banka with an API token: Zettl downloads your account movements every day and matches them with documents. Read-only, no right to send payments.