How to have an AI agent automatically mail paper invoices

Short answer

An agent (Claude, Cursor, a custom script) can mail an invoice as a paper letter through the hosted MCP server or the REST API with no human involved — just an address and content, and Postbot prints, envelopes, and mails it via Česká pošta. The first letter needs no credit; repeat sends run on prepaid credit.

Steps

  1. Connect your agent to Postbot. Add the hosted MCP server (/mcp) to the agent as a remote tool, or use the REST API with an API key — no installation.
  2. The agent calls send_letter_cz. It passes the recipient's address and the invoice content (PDF, markdown, or text) and chooses ordinary or registered.
  3. We print and mail the invoice. Česká pošta delivers it to the mailbox; registered letters come with a tracking number.

Frequently asked questions

Does the agent need credit up front?

The first letter can be sent without credit — an unfunded call returns a payment link for the exact amount. Repeat invoice sends need prepaid credit tied to the API key.

How does the agent know an invoice arrived?

The get_letter_status tool returns delivery status by tracking number, which Česká pošta assigns to registered letters.

Does the MCP server need installing?

No — the hosted server at /mcp works with no installation, just add it to the agent as a remote tool (Streamable HTTP). A self-host option (bunx @postbot/mcp) is optional.

Can an invoice be sent with proof of delivery?

Yes — choose registered and you'll get a tracking number to follow delivery.