Crate x402_types 

Core types for the x402 payment protocol.

This crate provides the foundational types used throughout the x402 ecosystem for implementing HTTP 402 Payment Required flows. It is designed to be blockchain-agnostic, with chain-specific implementations provided by separate crates.

Overview

The x402 protocol enables micropayments over HTTP by leveraging the 402 Payment Required status code. When a client requests a paid resource, the server responds with payment requirements. The client signs a payment authorization, which is verified and settled by a facilitator.

Modules

• chain - Blockchain identifiers and provider abstractions (CAIP-2 chain IDs)
• config - Server configuration, CLI parsing, RPC config, and environment variable resolution
• facilitator - Core trait for payment verification and settlement
• networks - Registry of well-known blockchain networks
• proto - Wire format types for protocol messages (V1 and V2)
• scheme - Payment scheme system for extensible payment methods
• timestamp - Unix timestamp utilities for payment authorization windows
• util - Helper types (base64, string literals, money amounts)

Protocol Versions

The crate supports two protocol versions:

• V1 (proto::v1): Original protocol using network names (e.g., “base-sepolia”)
• V2 (proto::v2): Enhanced protocol using CAIP-2 chain IDs (e.g., “eip155:84532”)

Feature Flags

• cli - Enables CLI argument parsing via clap for configuration loading
• telemetry - Enables tracing instrumentation for debugging and monitoring

Modules

chain

Blockchain-specific types and providers for x402 payment processing.

config

Configuration types for x402 infrastructure.

facilitator

Core trait defining the verification and settlement interface for x402 facilitators.

networks

Known blockchain networks and CAIP-2 chain ID management.

proto

Protocol types for x402 payment messages.

scheme

Payment scheme implementations for x402.

timestamp

Unix timestamp utilities for x402 payment authorization windows.

util

Utility types and functions for x402.

Macros

lit_str

Creates a type that represents a specific string literal.