Primary Source Map

How to read these sources

Start with the x402 Foundation docs for current protocol behavior, then read the GitHub specs for scheme-level validation requirements. Use Coinbase docs for CDP facilitator details and migration notes. Use IETF and MDN for the underlying HTTP status-code context.

Provider docs such as Stripe, Cloudflare, Solana, and chain-specific guides are useful evidence of adoption and implementation patterns, but they may describe provider-specific facilitators, products, or network support. Do not generalize those details to every x402 integration without checking the protocol docs.

Source categories

For implementation, the most important pages are HTTP 402, Client / Server, Facilitator, Networks & Token Support, and the seller and buyer quickstarts. For migration, use the Coinbase v1-to-v2 matrix. For risk review, read exact, upto, batch settlement, payment identifier, and signed offers/receipts.

For market context, Coinbase and Cloudflare explain why the protocol exists and where it might go. Those pages are useful for framing, but production engineers should still build from the specs and current SDK docs.

Verification policy

Every page on x402docs.com links back to primary sources near the claims they support. When a source changes, the safest update path is to edit the central source registry first, then review every page that cites it.

This site avoids pretending that a provider-specific endpoint, feature, or launch claim is protocol-wide. If a page names a provider, it should say whose docs support that statement.

• Protocol claim: cite x402 Foundation docs or specs.
• HTTP status claim: cite RFC 9110 or MDN.
• Provider feature: cite that provider documentation.
• Ecosystem adoption: cite official provider or chain pages, not anonymous summaries.