COMPARISON
API Economy
Governance
x402 vs AP2
A settlement rail vs a governance spec.
These are not the same kind of thing. x402 settles money. AP2 specifies how an agent payment system should behave — audit, spend limits, verifiability — without picking a rail. Production stacks generally implement AP2 principles on top of x402 (and other rails).
x402
vs
AP2
Side-by-side
The dimensions that actually matter.
| Dimension | x402 | AP2 |
|---|---|---|
| Layer | Settlement rail | Governance spec |
| Owner | Coinbase + Cloudflare (open) | |
| Status | Live on Base mainnet | Specification |
| Multi-rail? | Stablecoin only | Rail-agnostic by design |
| What it ships | A working HTTP + crypto rail | A set of compliance principles |
| Implementations | Multiple facilitators (Coinbase, xpay, Corbits, etc.) | Stripe, Visa, x402-stack implementations |
Decision matrix
Which one, when.
x402
You ship x402 when…
- You actually need money to move between machines.
- You want sub-second, programmable, on-chain settlement.
- You are building the rail layer of an agent stack.
AP2
You implement AP2 when…
- Enterprise procurement asks "are you AP2-aligned?"
- You need a multi-rail governance vocabulary your finance team accepts.
- You are designing your control plane to outlive any single rail.
both
Use both when…
- You want AP2-aligned governance running on x402 settlement.
- You expect to add card rails (MPP, Stripe, Visa) later without rewriting policy.
- You need verifiable receipts for compliance + reconciliation.
Bottom line
AP2 is the spec. x402 is one of the rails AP2 anticipates. Asking "x402 or AP2" is like asking "TCP or HIPAA" — they live at different layers and you usually want both.
How xpay fits
xpay is an AP2-aligned implementation: audit trails (live), 6-dimensional spending limits (live), verifiable settlement (in development), running today on x402 with MPP and ACP support arriving alongside the rails.