tempo-x402-0.2.0 has been yanked.

tempo-x402

Pay-per-request APIs on the Tempo blockchain.

Live Demo · Documentation · crates.io

How It Works

┌────────┐         ┌────────┐         ┌─────────────┐         ┌───────┐
│ Client │         │ Server │         │ Facilitator │         │ Chain │
└───┬────┘         └───┬────┘         └──────┬──────┘         └───┬───┘
    │                  │                     │                    │
    │  GET /resource   │                     │                    │
    │─────────────────>│                     │                    │
    │                  │                     │                    │
    │  402 + payment   │                     │                    │
    │  requirements    │                     │                    │
    │<─────────────────│                     │                    │
    │                  │                     │                    │
    │  [sign EIP-712]  │                     │                    │
    │                  │                     │                    │
    │  GET /resource   │                     │                    │
    │  + X-PAYMENT hdr │                     │                    │
    │─────────────────>│                     │                    │
    │                  │                     │                    │
    │                  │  verify + settle    │                    │
    │                  │────────────────────>│                    │
    │                  │                     │  transferFrom()    │
    │                  │                     │───────────────────>│
    │                  │                     │<───────────────────│
    │                  │<────────────────────│                    │
    │                  │                     │                    │
    │  200 + content   │                     │                    │
    │<─────────────────│                     │                    │

Client requests a paid endpoint. Server returns 402 with price info. Client signs an EIP-712 payment authorization and retries. Server forwards to Facilitator, which verifies the signature and calls transferFrom on-chain to settle the payment. Server returns the content.

Architecture

Three services, one chain:

Component	What it does	Stack
Client	Signs payments, makes requests	Rust (`tempo-x402` crate) or any language with EIP-712
Server	Gates endpoints, returns 402, forwards payments	Rust, actix-web
Facilitator	Verifies signatures, settles on-chain	Rust, actix-web, alloy
Chain	Tempo Moderato (testnet), pathUSD token	EVM, TIP-20

The facilitator holds no funds — it just has approval to call transferFrom on behalf of clients who have pre-approved it.

Install

cargo add tempo-x402

Usage

use alloy::signers::local::PrivateKeySigner;
use x402::{TempoSchemeClient, X402Client};

#[tokio::main]
async fn main() {
    let signer: PrivateKeySigner = "0xYOUR_KEY".parse().unwrap();
    let client = X402Client::new(TempoSchemeClient::new(signer));

    let (response, settlement) = client
        .fetch("https://api.example.com/paid-endpoint", reqwest::Method::GET)
        .await
        .unwrap();

    println!("{}", response.text().await.unwrap());
    if let Some(s) = settlement {
        println!("tx: {}", s.transaction);
    }
}

Crates

Crate	Purpose
`tempo-x402`	Core library — types, signing, HTTP client
`tempo-x402-server`	Resource server with payment middleware
`tempo-x402-facilitator`	Payment verification and settlement

Network

Chain: Tempo Moderato (testnet)
Chain ID: 42431
Token: pathUSD 0x20c0000000000000000000000000000000000000 (6 decimals)
RPC: https://rpc.moderato.tempo.xyz

License

MIT

tempo-x402 0.2.0