rust

OKX Payments — Rust SDK

Rust SDKs for the x402 and MPP payment protocols. Designed for resource servers (sellers) that need to charge API consumers per request, with support for both single-shot purchases and streaming sessions.

Crates

目录 / Lib alias	Published name (crates.io)	Purpose
x402-core	okxweb3-app-x402-core	x402 protocol core: types, server logic, facilitator client, HMAC signing
x402-evm	okxweb3-app-x402-evm	x402 EVM mechanism (X Layer + EVM-compatible chains)
x402-axum	okxweb3-app-x402-axum	x402 axum middleware (Tower Layer / Service)
mpp-evm	okxweb3-app-mpp	OKX MPP EVM Seller SDK (SA API integration)
payment-router-axum	okxweb3-app-payment-router-axum	Dual-protocol (x402 + MPP) axum router

All crates publish under the okxweb3-app-* naming convention (org prefix

• Agent Payments Protocol product identifier + protocol + variant). Each crate is independently versioned and released — pick only what you need.

Quick install

Only x402 — any axum server that wants per-request payments via the x402 protocol:

[dependencies]
okxweb3-app-x402-axum = "0.2"

Only MPP — OKX merchants integrating the Machine Payments Protocol (channel-based pay-per-use):

[dependencies]
okxweb3-app-mpp = "0.2"

Both protocols — let HTTP clients pick whichever they support; the router auto-detects the request scheme and dispatches to the right backend:

[dependencies]
okxweb3-app-payment-router-axum = "0.2"

See each crate's own README for usage examples.

Examples

Runnable example servers live alongside each protocol:

• x402/examples — x402 photo / metered API servers.
• mpp/examples — MPP charge / session servers, plus a dual-protocol server using payment-router-axum.

cargo run -p x402-examples --example basic_server
cargo run -p mpp-examples --example mpp_photo_server
cargo run -p mpp-examples --example dual_protocol_server

Cargo consumer caveat: submodule fetch

This monorepo contains Solidity submodules under contracts/evm/lib/ (forge-std, OpenZeppelin, Permit2) that Rust consumers don't need. Cargo clones them by default, adding ~500 MB and a hard dependency on GitHub availability.

If you hit network errors resolving mpp-evm or x402-* as a git dependency, enable CLI-backed git fetch (which skips submodules when --recurse-submodules is not requested) in ~/.cargo/config.toml:

[net]
git-fetch-with-cli = true

Or run cargo --offline after a successful first fetch. A cleaner long-term fix is to host the Rust crates in a dedicated repository.

License

Licensed under the Apache License, Version 2.0. Note that this differs from the typical Rust ecosystem default of MIT OR Apache-2.0 dual licensing — please factor that in when choosing whether this SDK is compatible with your project.