Side by side
x402 vs AP2
Every row read live from the directory · updated 2026-08-30
Framing these as rivals misreads both. x402 is a narrow, shipped primitive: a server answers HTTP 402 with a price, the caller pays stablecoin, the request retries. AP2 is a broader mandate framework for agent-led purchasing across payment rails — and its crypto extension was built with Coinbase, so it can carry x402 rather than replace it.
The practical question is not which one wins but which layer you are working at. If you are metering an API call, that is x402's whole job. If you are handling a delegated purchase with authorisation and dispute semantics attached, that is what AP2 specifies. The table below compares them on the axes the directory tracks for both.
x402
EarlyOpen payment protocol enabling agents and apps to pay for APIs over HTTP using stablecoins.
Agent Payments Protocol (AP2)
ActiveOpen protocol from Google for secure agent-led payments across traditional and crypto rails, with a crypto-native x402 extension built with Coinbase, Ethereum Foundation, and MetaMask.
On the same axes
| x402 | Agent Payments Protocol (AP2) | |
|---|---|---|
| What it is | API / SDK | API / SDK |
| Chains | Base, Ethereum, Multichain, Solana | Ethereum, Base, Multichain |
| Interfaces | sdk | mcp, sdk |
| Standards | x402 | x402, mcp, a2a |
| Open source | Yes | Yes |
| Listing status | Early | Active |
| Last activity | 2026-08-26 | 2026-04-28 |
| Last release | 2026-04-13 | 2026-04-28 |
| Install proofA reproduced install means the documented setup was actually run, not that the project is safe. | Reproduced install | Self-reported install |
| VerificationSelf-reported is not verified. Only Verified and Audited are earned states. | Unverified | Verified |
| Sato ScoreHow open, active and verifiable the project is — not a safety, quality or returns grade. | 83 | 72 |
| GitHub starsA popularity signal, not a quality one. Listed last for that reason. | 149 | 2,937 |
Pick x402 if
- ·You are charging for a request — an API call, a query, a compute job — and want the smallest thing that works.
- ·You want an agent to pay without an account, a key, or a prior relationship with the seller.
- ·You want implementations available today: this directory tracks fifty listings that support x402.
Pick Agent Payments Protocol (AP2) if
- ·You need the mandate and authorisation layer around a purchase, not just the transfer.
- ·You need to span traditional and crypto rails rather than settle only in stablecoin.
- ·You are building toward merchant checkout, where the card networks' agent specs matter as much as the chain.
What this cannot tell you
Both are early, and neither listing's adoption figures are independently verified — self-reported volume is never presented as fact on this site. AP2's higher star count reflects a specification repository from a large vendor, not deployed usage; x402's lower one sits under a protocol with more shipped implementations in this directory. Star counts are the least meaningful row in the table, which is exactly why they are not the first one.
Related
Cite this page
Sato Hub. "x402 vs AP2." Sato Hub, updated 2026-08-30, accessed 2026-08-31. https://satohub.ai/compare/x402-vs-ap2This page is refreshed daily. Citations include the date so a reader can tell which snapshot a claim came from.
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