Question: signed receipts for selected x402 resource / payment-result handoffs?

Hi — I found x402scan while looking at x402 ecosystem infrastructure where paid API/resource calls, facilitator records, scan results, or transaction-linked resource outputs may need evidence that survives outside the original runtime.

I’m building BoundaryAttest, a small open-source project for portable signed receipts around selected claims, actions, artifacts, or handoffs that cross trust boundaries:

https://github.com/cullenmeyers/BoundaryAttest

The idea is not to replace x402scan, x402 discovery documents, facilitator records, payment records, transaction history, API logs, embedded wallet flows, or normal client/server observability. The receipt only proves a narrow claim:

a specific signer signed a specific claim, and the signed claim has not been altered.

x402scan seemed relevant because it sits near the exact boundary I’m studying: x402 resources can be discovered, priced, paid for just-in-time, called by agents/users, and then the result or scan record may later be handed to another workflow, customer, agent, reviewer, or dispute/debugging process.

A BoundaryAttest receipt could potentially bind selected events like:

• x402 resource URL or endpoint reference;
• discovery document hash;
• payment requirement hash;
• facilitator reference;
• payment/settlement reference;
• request digest;
• response/result hash;
• x402scan resource/check record hash, if relevant;
• status, such as discovered, payment-required, paid, settled, executed, failed, scanned, exported, or handed off;
• timestamp/event ID;
• signer/public key ID.

The strongest use case would be when an x402-paid resource result, scan/export record, facilitator-linked payment result, or downstream artifact is handed to another system or reviewer, and they should not have to fully trust a local screenshot, copied JSON, client-side log, or unverifiable dataset row.

BoundaryAttest would not prove the API result was correct, the payment was legally sufficient, the resource was safe, the seller was trustworthy, or the provider runtime was uncompromised. It would only prove that a specific claim about a selected x402 resource/payment/result/handoff was signed and has not been altered after export.

Does this kind of portable signed receipt fit anything you imagine around x402scan, x402 resource discovery, facilitator records, paid resource calls, or scan-result exports? Or are current discovery documents, payment records, transaction records, and x402scan data enough for the current scope?

No pressure if it is not relevant — I’m mainly trying to learn whether signed receipts are useful where APIs already settle value per request.

This is an exploratory proposal rather than an implementation task, and it names no files, tests, or entry points. First review x402scan's current resource discovery, facilitator/payment records, and scan-result export scope, then define whether portable signed receipts belong in the project and what concrete behavior would count as done.