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x402 Express Starter

An API that charges per request and an agent that pays for it, via the x402 standard on Cardano preprod.

New to x402 on Cardano? The x402 page has the full picture.

Get started

You need Node.js 20+ and a free Blockfrost project id. No browser wallet is needed, the starter generates its own.

Scaffold the project into a new my-app folder:

Terminal

npx giget@latest gh:cardano-foundation/developer-portal/examples/templates/x402-express my-app

Install dependencies, then generate a preprod wallet:
Terminal
```
cd my-app
npm install
cp .env.example .env
npm run wallet
```
Copy the mnemonic into .env, set your Blockfrost project id and a seller address, and fund the printed address at the preprod faucet.
Run it, in two terminals:
Terminal
```
npm run facilitator
npm run demo
```

The agent pays the route and the terminal prints the receipt with an explorer link. Expect 20 to 60 seconds for on-chain confirmation.

This directory is open source. Open a pull request to update or correct this entry.