Illahi Khan developed the Invy Wallet Holdings Service for the coinbase/x402 repository, enabling users to view token holdings across both Ethereum and Solana. He approached the problem by designing and implementing backend services that aggregate cross-chain wallet data, exposing this information through a well-structured API. Using skills in API integration, full stack development, and JSON, Illahi established a repeatable pattern for cross-chain data services that supports future analytics features. His disciplined code contributions ensured reliable cross-chain data flow, expanding asset visibility for users. The work laid a solid foundation for enhanced portfolio transparency and analytics within the x402 ecosystem.