Radr is a Solana-based privacy stack for x402-enabled commerce. Core modules include ShadowPay (x402 ZK private payment rail with PDA escrow and encrypted amounts), ShadowID (anonymous identity with rate-limited credentials), and ShadowMSG (encrypted on-chain messaging). It enables agents and merchants to settle, verify, and communicate on-chain with minimal metadata exposure, providing interoperable rails for automated payments and subscriptions.