Question: should autonomous x402 payments have a pre-spend risk hook?

[jackinehu]

I am validating a small buyer-side x402 guardrail and would value blunt feedback from a wallet-native agent project like Franklin.

The narrow use case:

Before an autonomous agent pays an unknown x402 endpoint, call a cheap preflight API that returns strict JSON:

• verdict: allow | caution | block
• decision.shouldPay
• decision.requiresHumanReview
• reason codes
• Bazaar discovery evidence

Endpoint:
POST https://api-production-2800.up.railway.app/v1/x402-risk

Buyer guide:
https://api-production-2800.up.railway.app/v1/buyer-guide

Free preview before paying:
https://api-production-2800.up.railway.app/v1/payment-preview

Payment help:
https://api-production-2800.up.railway.app/v1/payment-help

Example:
https://github.com/jackinehu/AgentSpendGuard/blob/main/examples/x402-buyer-agent-policy.ts

Question for Franklin:
Would a pre-spend hook like this fit before Franklin pays unknown x402 resources, or would wallet-side caps/allowlists make this unnecessary?

I am not asking for promotion. I am trying to find out whether this is a real buyer-agent need or a false problem.

[egoriklok]

Yes. I would put a pre-spend risk hook before the x402 payment attempt, not only after a failed charge.

Free public snapshot:

• The hook should return allow / caution / block with reason codes before wallet spend.
• Minimum fields: endpoint identity, quoted amount + unit, policy/version hash, spend cap source, receipt expectation, revocation/dispute path, and whether human review is required.
• After payment, the wallet/tooling should attach charge evidence and settlement receipt so the agent can learn from the outcome.

No invoice, no payment link, no private endpoint; this is only the public readiness answer.