Payment proof
Rail, asset, amount, payee, nonce, expiry, transaction/signature, and payment binding where supported.
Receipts and proof
Paid agent work needs an audit trail humans and agents can read.
A receipt should say what was requested, what was paid, what was fulfilled, what proof exists, and whether reconciliation confirmed it.
Invocation proof
Resource, method, payload hash, output summary, result hash, provider request id, and idempotency key.
Operator state
Confirmed, failed, missing, replay-blocked, refund/credit queue, reconciliation drift, and payout packet state.
External trust: public proof endpoints are intentionally safe to read. Private logs, secrets, customer payloads, and sensitive settlement internals stay out of public artifacts.