During May 2026, this developer delivered a feature for the assistant-ui/assistant-ui repository that introduced source-document parts support within the AI SDK. The work focused on preserving document sources throughout conversion and serialization processes, enhancing metadata handling, and integrating new React-based UI components to display document provenance to end users. Utilizing TypeScript and JavaScript, the implementation strengthened data integrity and traceability across document workflows. The developer collaborated closely with other team members to ensure seamless integration between the SDK and UI layers, laying a technical foundation for future expansion of source-document features throughout both the user interface and the underlying SDK.