Module server 

Available on crate feature server only.

Axum middleware for enforcing x402 payments on protected routes (V2-only).

This middleware validates incoming payment headers using a configured x402 facilitator, verifies the payment, executes the request, and settles valid payments after successful execution. If the handler returns an error (4xx/5xx), settlement is skipped.

Returns a 402 Payment Required response if the request lacks a valid payment.

See X402Middleware for full configuration options. For low-level interaction with the facilitator, see facilitator::FacilitatorClient.

Settlement Modes

• SettlementMode::Sequential (default): verify → execute → settle.
• SettlementMode::Concurrent: verify → (settle ∥ execute) → await settle.
• SettlementMode::Background: verify → spawn settle (fire-and-forget) → execute → return.

Re-exports

pub use cors::X402_EXPOSED_HEADERS;

pub use cors::ensure_expose_headers;

pub use hooks::DynPaygateHooks;

pub use hooks::NoopPaygateHooks;

pub use hooks::PaygateHooks;

pub use hooks::ProtectedRequestOutcome;

pub use layer::SettlementMode;

pub use layer::X402LayerBuilder;

pub use layer::X402Middleware;

pub use paygate::BackgroundSettlementTracker;

pub use paygate::Paygate;

pub use paygate::PaygateBuilder;

pub use paygate::PaygateError;

pub use paygate::ResourceTemplate;

pub use paygate::VerificationError;

pub use paygate::VerifiedPayment;

pub use paygate::settlement_to_header;

pub use pricing::DynamicPriceTags;

pub use pricing::PriceTagSource;

pub use pricing::StaticPriceTags;

pub use status::reason_to_status;

pub use upto::UptoActualAmount;

Modules

cors

CORS helpers for exposing x402 response headers to browser clients.

facilitator

A r402_core::facilitator::Facilitator implementation that interacts with a remote x402 Facilitator over HTTP.

hooks

Paygate-level lifecycle hooks.

layer

Axum middleware for enforcing x402 payments on protected routes.

paygate

Core payment gate logic for enforcing x402 payments (V2-only).

pricing

Price tag sources for the x402 payment gate.

status

Maps x402 error reasons to HTTP status codes.

upto

HTTP-level support for the x402 “upto” scheme.