Stripe and Tempo launched the Machine Payments Protocol on March 18, 2026. PostalForm was part of the launch story because physical mail is a useful test for agentic commerce: the agent is not only buying a digital file or API response, it is paying for a real-world task to be fulfilled.
Stripe’s launch post named PostalForm as a service that helps agents pay to print and send physical mail. For us, that was the clearest public signal that agentic payments are moving beyond demos and into useful workflows.
Why mail is a good MPP use case
Agents frequently encounter workflows that end outside the browser:
- A letter has to be mailed to cancel an account.
- A dispute packet needs to be sent with documentation.
- A notice or form packet has to reach a physical address.
- A user needs status after the document enters fulfillment.
MPP gives an approved agent a payment protocol for that kind of task. The agent can request the resource, receive a payment challenge, authorize payment through the supported rails, and retry with the credential required to complete the order.
What PostalForm adds around the payment
Payment is only one piece of the mail workflow. PostalForm also needs to handle document rendering, address validation, printable preview, idempotent order creation, routing, fulfillment status, and refunds or support paths when something goes wrong.
That is why our MPP work sits beside safer human-review flows. Hosted checkout remains the right default when a person should inspect and approve the mailing. MPP is for runtimes where the owner has explicitly allowed autonomous spending.
Source note
Stripe’s Introducing the Machine Payments Protocol announcement publicly named PostalForm as an MPP use case for agent-paid physical mail.