s402 vs x402
Both belong to the HTTP 402 family group on this map. The map lists them as complementary: sites and agents commonly implement both. x402 is a prerequisite of s402.
| s402 s402 | x402 | |
|---|---|---|
| Lifecycle step | 7 Pay: Settle the bill | 7 Pay: Settle the bill |
| Answers | How can an agent pay a Sui-native resource using six payment schemes (including prepaid batching and escrow), while staying wire-compatible with plain x402 clients? | How can an HTTP client pay per-request or per-resource, in stablecoins, without accounts, API keys, or signup? |
| Governed by | Single open-source project (s402-protocol on GitHub); no standards body, no foundation; explicitly a 'profile' of x402 rather than a competing standards effort | x402 Foundation, a Series of LF Projects, LLC (Linux Foundation); operational launch announced 2026-07-14; Executive Director Michael Hursta from 2026-10-01; 50+ members |
| Status (issuer's words) | Archived repository (observed 2026-10-16) | Open, neutral standard for internet-native payments |
| Phase | deprecated | living |
| Version | Wire Format Specification v1, Draft, dated March 2026 (repository has continued past this to align with x402 v2) (2026-03) | x402 protocol specification v2, transports-v2/http.md |
| Form / transport | HTTP header | HTTP header |
| Found at | none — no /.well-known/s402.json was found; discovery is per-request via the 402 envelope, matching x402's model | none — signalled per-request via the 402 status code, not a fixed well-known path |
| Adoption | unmeasured | claimed — x402 Foundation (x402.org live dashboard) |
| Evidence | 4 verified | 5 verified |
| Primary use case | Accept payments from agents | Accept payments from agents |
| Last verified | 2026-10-19 (current) | 2026-10-19 (current) |
| Specification | https://raw.githubusercontent.com/s402-protocol/core/main/docs/specification.md | https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/http.md |
When to use which
- Choose s402 when your question is “How can an agent pay a Sui-native resource using six payment schemes (including prepaid batching and escrow), while staying wire-compatible with plain x402 clients?” and you accept its maturity: phase deprecated, adoption unmeasured. It is no longer maintained; prefer its successor.
- Choose x402 when your question is “How can an HTTP client pay per-request or per-resource, in stablecoins, without accounts, API keys, or signup?” and you accept its maturity: phase living, adoption claimed (x402 Foundation (x402.org live dashboard)).