Plan your agent payment stack
Build a shareable agent payment plan with counterparties, operational owners, unknowns and a prioritized sandbox checklist.
Evidence, not endorsement
A research and planning tool, not a vendor certification. Sources describe specific products, not every service offered by a company. Unknown means not established by the sources reviewed, not unsupported. grug402 sandbox tests do not test these vendors. Operational owners are suggested team contacts, not legal liability assignments.
Editorial review: 2026-10-08. Evidence older than 90 days needs rechecking; source check dates are not release dates.
A deterministic planning tool
Choose retailer, commerce platform or IT team; select a goal and up to nine participants. Leave roles generic when a provider is undecided.
The interactive planner supports editing, removing and resetting selections, a public share link containing selection IDs only, and a Markdown checklist download. It never executes payments.
Selecting vendors does not establish pairwise interoperability. Confirm protocol version, consent, recipient, accepted payment methods, settlement behavior and recovery with each provider.
Suggested operational owners are team contacts, not legal liability determinations.
Questions to resolve
Who may authorize spend, and what budget, resource and recipient is that approval bound to?
Who reconciles an uncertain payment before a retry?
Who handles paid-but-not-delivered incidents, support, cancellation and refunds?
Relevant sandbox tests — not vendor results
These are controlled grug402 scenarios. A passing sandbox request does not certify a company, integration, checkout or refund process.
- P1: A payment that completes — Establish a baseline before diagnosing failure cases. Suggested owner: Payments engineering.
- P1: Keep a spend within its limit — A quoted price can exceed the buyer's permitted per-call spend. Suggested owner: Agent product and security.
- P1: Bind approval to the right service — A payment must not be redirected to an unexpected resource host. Suggested owner: Agent product and security.
- P1: Interpret the amount correctly — A decimals mismatch can change the economic amount dramatically. Suggested owner: Payments engineering and treasury.
- P1: Check the intended recipient — A valid-looking request may name the wrong receiving address. Suggested owner: Payments engineering.
- P1: Retry without a duplicate charge — Lost responses should not cause the same purchase intent to be paid again. Suggested owner: Application engineering.
- P1: Handle paid-but-not-delivered — Settlement can succeed while the application fails to deliver. Suggested owner: Payments and customer operations.
- P2: Resolve an uncertain settlement — A server error does not establish whether money moved. Reconcile before retrying. Suggested owner: Payments operations and facilitator operator.
- P1: Establish safe edge behavior — Challenges and personalized paid responses need deliberate cache controls. Suggested owner: CDN and application engineering.
- P2: Avoid stale payment instructions — A cached challenge can advertise an expired quote or outdated payment terms. Suggested owner: CDN and payments engineering.
- P1: Prevent paid content leaking from cache — A shared cache can serve one payer's content to another visitor. Suggested owner: CDN and security.
- P2: Allow valid payment credentials through — Security policy may reject a legitimate payment retry. Suggested owner: Network and security.
- P2: Coordinate edge and settlement timeouts — A timeout can leave the buyer unsure whether the service was paid. Suggested owner: Network and payments operations.