During November 2025, Antonijevic contributed to the hey-api/openapi-ts repository by enhancing the TanStack Query integration with a TypeScript-based solution that introduced type-safe queryOptions configuration. This work improved autocompletion and compile-time safety for developers configuring queries, reducing the risk of misconfiguration and streamlining onboarding. Antonijevic also addressed a bug by updating TypeScript declaration source map URLs, which improved debugging and maintainability of the generated client code. The implementation demonstrated strong skills in API development, testing, and type safety, with careful alignment of test and build workflows to ensure compatibility with the new typings and declarations throughout the project.