Gap note
x402 gaps
x402 is a gap note assembled on 2026-10-21. It quotes primary pages for settlement asset, spend controls, revocation, protocol composition, license, governance body, and cross-company use. A line that says not documented uses the day that page was read. The note does not rank the listing.
Last verified 2026-10-21
Sources
x402 listing · Protocol compatibility · Gaps JSON
| Dimension | Status |
|---|---|
| Settlement asset | Documented |
| Spend controls | Omitted |
| Revocation | Omitted |
| Protocol composition | Documented |
| License | Documented |
| Governance body | Documented |
| Cross-company use | Documented |
Settlement asset
Documented
The x402.org FAQ says stablecoin payments are the primary use case, and that the protocol is extensible to traditional payment methods.
x402 site · Read 2026-10-21
The same FAQ says x402 supports EVM compatible chains, Solana, and more.
x402 site · Read 2026-10-21
The Linux Foundation announcement says payment types range from traditional cards to stablecoins.
Linux Foundation announcement of the x402 Foundation, 14 July 2026 · Read 2026-10-21
Spend controls
No checked source for this dimension in this note.
Revocation
No checked source for this dimension in this note.
Protocol composition
Documented
The A2A x402 extension v0.2 spec defines an A2A extension for x402 payments, including an embedded flow inside AP2.
A2A x402 payments extension v0.2 · Read 2026-10-21
AP2's site links a human not present sample that uses x402.
AP2 protocol documentation · Read 2026-10-21
The MPP documentation index includes a guide for using MPP with x402.
MPP protocol site · Read 2026-10-21
Mastercard's 2026-10-20 article says Agent Pay for Machines builds on x402.
Mastercard Agent Pay for Machines at Cloudflare Connect, 2026-10-20 · Read 2026-10-21
ERC-8004 says examples show x402 payments enriching feedback, and that payments are outside the ERC.
ERC-8004 Trustless Agents · Read 2026-10-21
License
Documented
Apache-2.0. The GitHub license API reported this SPDX identifier on 2026-10-21.
GitHub repository x402-foundation/x402 · Read 2026-10-21
Governance body
Documented
The Linux Foundation announcement on 14 July 2026 says Coinbase contributed the protocol and the x402 Foundation stewards it.
Linux Foundation announcement of the x402 Foundation, 14 July 2026 · Read 2026-10-21
Cross-company use
Documented
The Linux Foundation announcement on 14 July 2026 says Coinbase contributed the protocol and the x402 Foundation stewards it.
Linux Foundation announcement of the x402 Foundation, 14 July 2026 · Read 2026-10-21
Mastercard's 2026-10-20 article says Agent Pay for Machines builds on x402.
Mastercard Agent Pay for Machines at Cloudflare Connect, 2026-10-20 · Read 2026-10-21
AP2's site links a human not present sample that uses x402.
AP2 protocol documentation · Read 2026-10-21
Questions
- What does not documented mean?
- Not documented means the cited page does not state the fact. The line names that page and the day it was read. It is not a claim that the fact is false.
- What does omitted mean?
- Omitted means this note has no checked source for that dimension. The dimension was left out rather than filled in.
- Does the index rank these products?
- No. The table can be sorted by name, by dimension status, or by checked date. Sort order is not a score.
- Where is the machine readable file?
- GET /data/gaps.json. The file includes every note, the cited sources, and the read dates.