> nestjs-file-uploads

Secure file handling, Validation, and S3 streaming. Use when implementing secure file uploads, validation, or S3 streaming in NestJS. (triggers: **/*.controller.ts, FileInterceptor, Multer, S3, UploadedFile)

fetch
$curl "https://skillshub.wtf/HoangNguyen0403/agent-skills-standard/nestjs-file-uploads?format=md"
SKILL.mdnestjs-file-uploads

File Upload Patterns

Priority: P0 (FOUNDATIONAL)

Secure file upload handling with validation and storage patterns.

  • Magic Bytes: NEVER trust content-type header or file extension.
    • Tool: Use file-type or mmmagic to verify the actual buffer signature.
  • Limits: Set strict limits: { fileSize: 5000000 } (5MB) in Multer config to prevent DoS.

Streaming (Scalability)

  • Memory Warning: Default Multer MemoryStorage crashes servers with large files.
  • Pattern: Use Streaming for any file > 10MB.
    • Library: multer-s3 (direct upload to bucket) or busboy (raw stream processing).
    • Architecture:
      1. Client requests Signed URL from API.
      2. Client uploads directly to S3/GCS (Bypassing API server completely).
      3. Pro Tip: This is the only way to scale file uploads infinitely.

Processing

  • Async: Don't process images/videos in the HTTP Request.
  • Flow:
    1. Upload file.
    2. Push FileUploadedEvent to Queue (BullMQ).
    3. Worker downloads, resizes/converts, and re-uploads.

🚫 Anti-Patterns

  • Do NOT use standard patterns if specific project rules exist.
  • Do NOT ignore error handling or edge cases.

┌ stats

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github stars341
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first seenMar 17, 2026
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┌ repo

HoangNguyen0403/agent-skills-standard
by HoangNguyen0403
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┌ tags

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