Machine-Readable Invoices and Cryptographic Receipts for Agents

A machine-readable invoice states what is owed in a form an agent can parse and pay; a cryptographic receipt is signed proof of what was paid and for what, that a third party can verify. For agent commerce both are essential: with no human to read a PDF or vouch for a transaction, the request for payment and the proof of it must be data, signed, and checkable — so an economic action between machines leaves evidence rather than a claim.

Invoice

Machine-readable request for payment

Receipt

Signed, verifiable proof of payment

Why

No human to read or vouch

Result

Evidence, not a claim

Evidence by default

In human commerce a receipt is a courtesy; in agent commerce it is the mechanism of trust. A signed receipt lets the payer prove it paid, the payee prove it was owed, and an auditor reconstruct the exchange — none of which can rest on either party’s word, because neither party is a person whose word a court would take at face value in the moment.

Questions

Why not just log the transaction?

A log is an assertion by one side. A signed receipt is verifiable by anyone, so it proves the exchange to a third party who trusts neither participant.

How do invoices and receipts relate to the ledger?

The receipt is the proof of an action; the ledger is the append-only record of it. Together they let a stranger audit what happened.