file-uploads
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.
Profile →npx skills add sickn33/agentic-awesome-skills --skill file-uploads --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
# 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. ### Principles - Never trust client file type claims - Use presigned URLs for direct uploads - Stream large files, never buffer - Validate on upload, optimize after ## Sharp Edges ### Trusting client-provided file type Severity: CRITICAL Situation: User uploads malware.exe renamed to image.jpg. You check extension, looks fine. Store it. Serve it. Another user downloads and executes it. Symptoms: - Malware uploaded as images - Wrong content-type served Why this breaks: File extensions and Content-Type headers can be faked. Attackers rename executables to bypass filters. Recommended fix: # CHECK MAGIC BYTES import { fileTypeFromBuffer } from "file-type"; async function validateImage(buffer: Buffer) { const type = await fileTypeFromBuffer(buffer); const allowedTypes = ["image/jpeg", "i
- Principles
- Sharp Edges
- Trusting client-provided file type
- No upload size restrictions
- User-controlled filename allows path traversal
- Presigned URL shared or cached incorrectly
- Validation Checks
- Only checking file extension
- User filename used directly in path
- Collaboration
- Delegation Triggers
- When to Use
- Limitations
What does the file-uploads skill do?
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.
How do I install it?
Run `npx skills add sickn33/agentic-awesome-skills --skill file-uploads --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From sickn33/agentic-awesome-skills, a repository with 44,414 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.