Coinbase Developer Platform has announced significant updates to its x402 protocol, now supporting all ERC-20 tokens. This enhancement allows developers to accept on-chain payments for any ERC-20 token, including popular options like USDC, EURC, and meme coins, utilizing EIP-3009 and Permit2 standards. Additionally, the protocol introduces a "Sign-in-with-X" feature, enabling users to log in with their wallets to access purchased content. This functionality supports EVM and Solana wallets, allowing sellers to offer payment-free access to returning customers. Furthermore, the launch of the x402 MCP package allows developers to monetize any MCP tool and integrate it into AI workflows.