seven agent payment protocols since february — here's the layer they all skip

the HN thread mapping the agent protocol ecosystem is worth reading. MCP, A2A, ACP, UCP, and payment rails — seven competing protocols since february 2026. stripe shipped MPP. coinbase and AWS put x402 in production. A2A includes a payments component (a2pay) built on ERC-7579 smart accounts.

the pattern here is consolidation pressure. seven protocols is not a stable state. some of these will win, some will lose, and the teams building on the wrong rail in 2026 will be doing a migration in 2027.

but there's a layer none of the seven protocols address, and it's the same gap regardless of which rail wins.

the accountability layer is orthogonal to the rails

whether your agent pays via MPP, x402, a2pay, or some combination — the payment execution problem is being solved aggressively by well-funded teams. stripe, coinbase, aws, and now stellar are all building payment primitives for agents.

what they're not building: the layer that proves a specific spend was within the agent's mandate. the signed receipt that links a payment to the upstream intent that authorized it. the creditworthiness signal that lets a counterparty evaluate whether this agent has a good payment history before accepting a transaction.

these are independent of the rails. they're the trust and accountability layer that sits above the payment execution layer.

why this matters during protocol consolidation

if you build your accountability layer on top of one protocol's specific receipt format, you're coupled to that protocol's survival. if x402 wins and you built on MPP receipts, you have a migration problem.

MnemoPay's Agent FICO and receipt model is designed to be rails-agnostic. it doesn't care whether the underlying transaction happened on Base, Stripe, or a2pay — it captures the intent signal and execution context at the layer above the payment execution.

672+ tests, v1.0.0-beta.1, 1.4K weekly npm downloads. the SDK is live while the protocol wars play out.

dev portal: https://mnemopay.com