x402 vs AP2
Same axes, every row read live from the directory. No winner declared.
- x402 Sato Score87
- Agent Payments Pr… Sato Score72
- Updated2026-10-15
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 HTTP 402 payment protocol, now at the x402 Foundation: agents pay per request in stablecoins, and by a newly merged spec, in bitcoin over Lightning.
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 | Payment Rail | Payment Rail |
| Chains | Base, Ethereum, Solana, Bitcoin, Multichain | Ethereum, Base, Multichain |
| Interfaces | sdk | mcp, sdk |
| Standards | x402 | x402, mcp, a2a |
| Open source | Yes | Yes |
| Listing status | Early | Active |
| Last commit or release | 2026-10-07 | 2026-06-17 |
| Last release | 2026-09-29 | 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. | 87 | 72 |
| GitHub starsA popularity signal, not a quality one. Listed last for that reason. | 6,683 | 3,207 |
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.
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Reference
QuestionsWhat people ask about this pageShowHide
Questions this comparison answers
- Is x402 or Agent Payments Protocol (AP2) more actively maintained?
- X402 is an open-source tool/service by x402 Foundation on Base, Ethereum, Solana and 2 more chains, last commit or release 2026-10-07, with a Sato Score of 87 out of 100 as of 2026-10-15. Agent Payments Protocol (AP2) is an open-source tool/service by Google on Ethereum, Base and Multichain, last commit or release 2026-06-17, with a Sato Score of 72 out of 100 as of 2026-10-15. Activity is a recency signal from public commits, releases and posts, not a quality judgment.
- Which one is open source?
- x402: Yes. Agent Payments Protocol (AP2): Yes. "Unknown" means Sato Hub found no license statement.
- Does Sato Hub declare a winner?
- No. Every row is read live from the directory and the page names what the data cannot settle. 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.
SourcesWhere the data comes fromShowHide
Sources — both projects' repositories and docs
Cite this pagePlain text, APA or BibTeXShowHide
Cite this page
Sato Hub. "x402 vs AP2." Sato Hub, updated 2026-10-15, accessed 2026-10-15. https://satohub.ai/compare/x402-vs-ap2Data last refreshed 2026-10-15; this page is rebuilt daily. Citations carry the date so a reader can tell which snapshot a claim came from. Catalog data is licensed CC-BY-4.0.
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