Module types 

Core types for the x402 protocol

This module defines all the core data structures and types used throughout the x402 protocol implementation. It provides type-safe representations of payment requirements, payment payloads, network configurations, and facilitator responses.

Architecture

The types module is organized as follows:

• network - Network configuration and chain-specific details
• payment - Payment requirements and payload structures
• facilitator - Facilitator configuration and response types
• discovery - Discovery API types for resource discovery
• constants - Protocol constants (networks, schemes, addresses)

Examples

Creating Payment Requirements

use rust_x402::types::{PaymentRequirements, Network};

let mut requirements = PaymentRequirements::new(
    "exact",                                          // scheme
    "base-sepolia",                                   // network
    "1000000",                                        // amount (1 USDC)
    "0x036CbD53842c5426634e7929541eC2318f3dCF7e",   // USDC contract
    "0x209693Bc6afc0C5328bA36FaF03C514EF312287C",   // recipient
    "https://api.example.com/resource",              // resource URL
    "API access payment",                             // description
);

// Set USDC metadata
requirements.set_usdc_info(Network::Testnet)?;

Creating Payment Payload

use rust_x402::types::{PaymentPayload, ExactEvmPayload, ExactEvmPayloadAuthorization};

let authorization = ExactEvmPayloadAuthorization::new(
    "0x857b06519E91e3A54538791bDbb0E22373e36b66",   // from
    "0x209693Bc6afc0C5328bA36FaF03C514EF312287C",   // to
    "1000000",                                        // value
    "1745323800",                                     // validAfter
    "1745323985",                                     // validBefore
    "0xf3746613c2d920b5fdabc0856f2aeb2d4f88ee6037b8cc5d04a71a4462f13480", // nonce
);

let payload = ExactEvmPayload {
    signature: "0x2d6a...".to_string(),
    authorization,
};

let payment = PaymentPayload::new("exact", "base-sepolia", payload);

// Encode to base64 for HTTP header
let encoded = payment.to_base64()?;

Network Configuration

use rust_x402::types::{Network, NetworkConfig, networks};

// Using the Network enum
let network = Network::Testnet;
println!("Network: {}", network.as_str());
println!("USDC: {}", network.usdc_address());

// Using NetworkConfig for detailed info
let config = NetworkConfig::base_sepolia();
println!("Chain ID: {}", config.chain_id);
println!("USDC Contract: {}", config.usdc_contract);

// Using constants
let usdc = networks::get_usdc_address("base-sepolia");
println!("USDC address: {:?}", usdc);

Facilitator Configuration

use rust_x402::types::FacilitatorConfig;
use std::time::Duration;

let config = FacilitatorConfig::new("https://x402.org/facilitator")
    .with_timeout(Duration::from_secs(30));

// Validate the configuration
config.validate()?;

Type Categories

Payment Types

• PaymentRequirements - Describes what payment is required
• PaymentPayload - Contains the actual payment authorization
• ExactEvmPayload - EVM-specific payment data (EIP-3009)
• ExactEvmPayloadAuthorization - Authorization parameters

Response Types

• VerifyResponse - Payment verification result
• SettleResponse - Payment settlement result
• SupportedKinds - Supported payment schemes and networks
• DiscoveryResponse - Resource discovery results

Configuration Types

• FacilitatorConfig - Facilitator client configuration
• NetworkConfig - Chain-specific network configuration
• Network - Simple network enum (Mainnet/Testnet)

Re-exports

pub use constants::networks;

pub use constants::schemes;

pub use discovery::DiscoveryResource;

pub use discovery::DiscoveryResponse;

pub use discovery::PaginationInfo;

pub use facilitator::AuthHeadersFn;

pub use facilitator::AuthHeadersFnArc;

pub use facilitator::AuthHeadersFnBox;

pub use facilitator::FacilitatorConfig;

pub use facilitator::SettleResponse;

pub use facilitator::SupportedKind;

pub use facilitator::SupportedKinds;

pub use facilitator::VerifyResponse;

pub use network::Network;

pub use network::NetworkConfig;

pub use payment::ExactEvmPayload;

pub use payment::ExactEvmPayloadAuthorization;

pub use payment::PaymentPayload;

pub use payment::PaymentRequirements;

pub use payment::PaymentRequirementsResponse;

pub use payment::X402_VERSION;

Modules

constants

Common constants for networks and schemes

discovery

Discovery API types

facilitator

Facilitator configuration and response types

network

Network configuration types

payment

Payment-related types