Worked on the coinbase/x402 repository to enhance the Go SDK by introducing an Extensions field to both SettleResponse and VerifyResponse, aligning these structures with their TypeScript SDK counterparts. This update focused on improving cross-SDK interoperability and enabling richer data contracts for multi-language clients. The approach emphasized careful API design and backend development in Go, ensuring that the SDK could support future metadata extensions and more flexible data handling. No major bugs were addressed during this period, with efforts concentrated on evolving the API surface to reduce integration friction and support seamless workflows across different programming environments and SDKs.