Send Letters via API - automated & legally secure
Send physical letters directly from your application or through your AI agent. We handle printing, enveloping and shipping within Germany - paid in real-time via USDC.
Comparison vs. Manual
| Feature | AgentBureau | Classic |
|---|---|---|
| Time required | < 1 second | 15 minutes |
| Costs (incl. postage) | 3.00 USDC | ~1.10 € + Staff |
| Scalability | Unlimited | Low |
| AI Capable | Yes (x402) | No |
How automated letter sending works
Request
Call the endpoint with an Idempotency-Key. Get a 402 Payment Required response with an intent ID.
Pay
Send USDC on Base to the provided wallet address. This registers your payment intent on-chain.
Authorize
Sign the intent ID with your wallet. This cryptographically binds the payment to your request.
Verify
Retry with your transaction hash and signature. Your service is executed within our SLA.
Why the AgentBureau Letter API?
In Germany, physical mail is often still unavoidable - be it for terminations, correspondence with authorities or invoices. The AgentBureau Letter API builds the bridge between modern Web3 technologies and the classic postal system.
Pingen Backend
We use Pingen as a reliable partner for printing and delivering your letters.
Tracking & Status
Each letter receives a tracking ID so that you and your agent always know where the shipment is.
No account necessary
No monthly fees or minimum sales. Only pay for the letter you actually send.