During June 2026, contributed to the DefinitelyTyped/DefinitelyTyped repository by enhancing the sdp-transform TypeScript typings to support an array of msid objects, addressing the need for accurate multi-stream SDP representations. This work involved updating type definitions, implementing comprehensive tests to validate the new msid structure, and incrementing the package version to v3.0 to clearly signal a breaking change. The approach emphasized correctness and reliability for downstream consumers integrating with WebRTC pipelines. Demonstrated proficiency in TypeScript, type definition management, and automated testing, ensuring safer upgrades and improved developer experience for projects relying on precise media stream identifier handling.