micropayment
A micropayment is a payment small enough that the cost of collecting it matters. On the machine-payment rails that is not a figure of speech: each rail publishes a minimum amount it will accept. The minimums differ, so the rail an endpoint settles on decides what it can charge for.
The floor is published rather than folkloric. Stripe's machine-payments documentation lists a minimum for card payments made through shared payment tokens and a separate, lower minimum for stablecoin payments, each figure on its own page. This entry links that page instead of repeating the figures, because a floor moves and a link does not.
The consequence is a design constraint rather than a detail. An endpoint charging per call has to charge at least the floor of the rail it settles on. The rail therefore decides whether pricing a single call is possible at all, which is the practical reason stablecoin rails appear in this space beside card rails.
The word is also used loosely for any small amount, which is why the floor is worth naming. A payment below a rail's minimum is not a small payment on that rail; it is not a payment on that rail.
→ probe402 records the amount each tracked endpoint quoted at each check, in the asset and unit the endpoint stated — open an endpoint from the endpoint list.
Sources
- Machine paymentsStripe documentation
- The Machine Payments Protocol specification siteMachine Payments Protocol
Related pay-per-call API · stablecoin · machine payment