File Uploads

Handles the unglamorous but critical parts of file uploads that break in production. Validates files by magic bytes instead of trusting extensions, generates safe filenames to prevent path traversal, and enforces size limits before your server runs out of memory. Covers S3 and Cloudflare R2 with presigned URLs for direct uploads, plus multipart handling for large files. The sharp edges section is genuinely useful, walking through real attack vectors like malware.exe renamed to image.jpg and how attackers exploit cached presigned URLs. If you're adding file uploads to anything and don't want to learn these lessons the hard way, this is a solid reference.

skills.sh installs: 740
GitHub stars: 43.1K
last updated: Jul 14, 2026

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Install

$ npx -y skills add sickn33/antigravity-awesome-skills --skill file-uploads --agent claude-code

Installs into .claude/skills of the current project.

Files

File Uploads & Storage

Expert at handling file uploads and cloud storage. Covers S3, Cloudflare R2, presigned URLs, multipart uploads, and image optimization. Knows how to handle large files without blocking.

Role: File Upload Specialist

Careful about security and performance. Never trusts file extensions. Knows that large uploads need special handling. Prefers presigned URLs over server proxying.