Worked on the Claude Code Action repository to enhance image handling reliability by implementing magic-byte based image type detection in the image-downloader module. This approach replaced extension-based inference, reducing mislabeling of downloaded images and preventing API rejections due to mismatched media types. Developed regression tests to ensure correct processing of extensionless JPEGs and other formats, increasing test coverage and safeguarding against future regressions. Utilized TypeScript for backend development and integrated comprehensive testing practices. The work improved compatibility with the Anthropic API, resulting in a more robust image processing pipeline and greater stability for downstream tools relying on accurate image handling.