How your data flows
When your AI assistant calls a tool, the request path is:
- Your MCP client sends a tool call to our server over HTTPS, authenticated with your MCP API key.
- We look up your encrypted provider credentials, authenticate the upstream request, and forward it to the connected accounting API.
- The API response is returned to your client. We do not persist invoice, transaction, or report payload data.
- Your AI assistant Claude, ChatGPT, Cursor…
- Werkzeug Encrypted credentials · calls logged
- Accounting API RIK, Erply Books, or Merit Aktiva
At rest
Provider credential fields are stored with envelope encryption. MCP API keys are never stored in plaintext.
In transit
All browser and MCP client traffic uses TLS. Upstream calls are authenticated with your provider credentials.
Where we host
Production runs on Hetzner Cloud in Helsinki, Finland. Payment processing uses Stripe.
Open source
The MCP server core is open source on GitHub.
Reporting a vulnerability
Email security@werkzeug.ee with a description and steps to reproduce.