Creating Python x402 Facilitator Services

Build FastAPI-based facilitator services that verify and settle x402 payments on-chain for Algorand (AVM), with optional multi-network support for EVM and SVM.

Prerequisites

Before using this skill, ensure:

1. Python 3.10+ is installed
2. x402-avm package is available: pip install "x402-avm[avm,fastapi]"
3. Algorand private key is available as a Base64-encoded 64-byte key (32-byte seed + 32-byte pubkey) in AVM_PRIVATE_KEY environment variable
4. Algod node access via AlgoNode (default) or custom node via ALGOD_SERVER / ALGOD_TOKEN

Core Workflow: Facilitator Payment Lifecycle

The facilitator sits between the resource server and the blockchain, handling payment verification and settlement: