Creating x402 Facilitator Services

Build facilitator services that verify payment transactions are valid, settle them on-chain, and optionally catalog discovered resources via the Bazaar extension.

Prerequisites

Before using this skill, ensure:

1. Node.js with TypeScript support
2. An Algorand account with ALGO for covering transaction fees during settlement
3. algosdk installed for transaction signing, simulation, and submission

Core Workflow: What a Facilitator Does

A facilitator is the trusted intermediary between a resource server and the blockchain. It performs two operations:

1. Verify -- Confirms that a payment transaction group is valid (correct amounts, recipients, signatures, timing) without submitting to the network
2. Settle -- Submits the verified transaction group to the Algorand network, co-signing the fee-payer transaction