Crate x402_reqwest 

Reqwest middleware for automatic x402 payment handling.

This crate provides a X402Client that can be used as a reqwest middleware to automatically handle 402 Payment Required responses. When a request receives a 402 response, the middleware extracts payment requirements, signs a payment, and retries the request with the payment header.

Quickstart

use x402_reqwest::{ReqwestWithPayments, ReqwestWithPaymentsBuild, X402Client};
use x402_chain_eip155::V1Eip155ExactClient;
use alloy_signer_local::PrivateKeySigner;
use std::sync::Arc;
use reqwest::Client;

// Create an X402 client and register scheme clients
let signer = Arc::new("PRIVATE_KEY".parse::<PrivateKeySigner>().unwrap());
let x402_client = X402Client::new()
    .register(V1Eip155ExactClient::new(signer));

// Build a reqwest client with x402 middleware
let http_client = Client::new()
    .with_payments(x402_client)
    .build();

// Use the client - payments are handled automatically
let response = http_client
    .get("https://api.example.com/protected")
    .send()
    .await?;

Registering Scheme Clients

The X402Client uses a plugin architecture for supporting different payment schemes. Register scheme clients for each chain/network you want to support:

• [V1Eip155ExactClient] - EIP-155 chains, x402 V1 protocol, “exact” payment scheme
• [V2Eip155ExactClient] - EIP-155 chains, x402 V2 protocol, “exact” payment scheme
• [V1SolanaExactClient] - Solana chains, x402 V1 protocol, “exact” payment scheme
• [V2SolanaExactClient] - Solana chains, x402 V2 protocol, “exact” payment scheme

See X402Client::register for more details on registering scheme clients.

Payment Selection

When multiple payment options are available, the X402Client uses a [PaymentSelector] to choose the best option. By default, it uses [FirstMatch] which selects the first matching scheme. You can implement custom selection logic by providing your own selector.

See X402Client::with_selector for custom payment selection.

Structs

ClientSchemes

Internal collection of registered scheme clients.

ReqwestWithPaymentsBuilder

Builder for creating a reqwest client with x402 middleware.

X402Client

The main x402 client that orchestrates scheme clients and selection.

Traits

ReqwestWithPayments

Trait for adding x402 payment handling to reqwest clients.

ReqwestWithPaymentsBuild

Trait for building the final client from a ReqwestWithPaymentsBuilder.

Functions

parse_payment_required

Parses a 402 Payment Required response into a proto::PaymentRequired.