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 facilitator::FacilitatorClient;

pub use facilitator::FacilitatorClientError;

pub use hooks::DynPaygateHooks;

pub use hooks::PaygateHooks;

pub use hooks::ProtectedRequestOutcome;

pub use middleware::SettlementMode;

pub use middleware::X402Layer;

pub use middleware::X402Middleware;

pub use paygate::Paygate;

pub use paygate::PaygateBuilder;

pub use paygate::PaygateError;

pub use paygate::ResourceTemplate;

pub use paygate::VerifiedPayment;

pub use paygate::X402_EXPOSED_HEADERS;

pub use paygate::ensure_expose_headers;

pub use paygate::reason_to_status;

pub use paygate::settlement_to_header;

pub use pricing::DynamicPriceTags;

pub use pricing::PriceTagSource;

pub use pricing::StaticPriceTags;

pub use tracker::BackgroundSettlementTracker;

pub use upto::SETTLEMENT_OVERRIDES_HEADER;

pub use upto::UptoActualAmount;

pub use upto::marshal_settlement_overrides;

pub use upto::resolve_response_settlement_amount;

pub use upto::set_settlement_overrides;

pub use upto::set_settlement_overrides_on_response;

pub use upto::settlement_overrides_header_name;

pub use upto::take_settlement_overrides_header;

Modules

facilitator

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

hooks

Paygate-level lifecycle hooks.

middleware

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.

tracker

In-flight counter for background settlement tasks.

upto

HTTP-level support for the x402 upto scheme (partial settlement).

Structs

SettlementOverrides

Official partial-settlement overrides (amount atomic / percent / dollar). Official wire shape for partial settlement (upto billing by actual usage).