# 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. Use when: file upload, S3, R2, presigned URL, multipart.

- Skill: `odjaramillo/file-uploads-2` (Agent Skill)
- Install (CLI): `npx skillmds@latest add odjaramillo/file-uploads-2`
- Raw SKILL.md: https://api.skillmd.com/api/skills/odjaramillo/file-uploads-2/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: DevOps & Infra
- Author: odjaramillo (https://skillmd.com/u/odjaramillo)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/odjaramillo/file-uploads-2

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# File Uploads & Storage

**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.

## ⚠️ Sharp Edges

| Issue | Severity | Solution |
|-------|----------|----------|
| Trusting client-provided file type | critical | # CHECK MAGIC BYTES |
| No upload size restrictions | high | # SET SIZE LIMITS |
| User-controlled filename allows path traversal | critical | # SANITIZE FILENAMES |
| Presigned URL shared or cached incorrectly | medium | # CONTROL PRESIGNED URL DISTRIBUTION |