Integrates the Base Account SDK for authentication and payments, encompassing Sign in with Base (SIWB), Base Pay, Paymasters, Sub Accounts, Spend Permissions, Prolinks, and batch transactions. Utilize this skill when developing applications requiring wallet authentication, USDC payments, sponsored transactions, smart wallet features, recurring subscriptions, shareable payment links, or any onchain interaction on Base. It supports functionalities like adding "Sign in with Base", implementing a "SIWB button", accepting "USDC payments" via "Base Pay", configuring "paymaster setup" for "gas sponsorship", creating a "smart wallet" with "sub account" and "spend permissions", or generating a "payment link".