End-to-end Radius Network development playbook. Stablecoin-native EVM with sub-second finality and 2.5M TPS. Uses @radiustechsystems/sdk (viem-native) with radiusWalletActions() decorator for wallet clients. wagmi for React wallet integration. Foundry for smart contract development and testing. Covers micropayment patterns (pay-per-visit content, real-time API metering, streaming payments), stablecoin-native fees via Turnstile, batch transactions, ERC-20 operations, SDK event watching, and EVM compatibility differences from Ethereum.