Uploads Overview

Laju Go provides two upload mechanisms, each for a different use case. Picking the right one is a matter of file size and whether you need the result back immediately.

The two mechanisms

Multipart FormData

One POST request, CSRF protected, response includes the file URL. Best for small files (< 5MB) where you need to update the database immediately — like avatars and profile photos.

TUS resumable uploads

Chunked, resumable, handles network failures. Best for large files (≥ 100MB, no hard limit) where the upload might fail mid-way — like videos and archives.

When to use which

Your file is…	Use	Why
An avatar, profile photo, or any image < 5MB	Multipart	One POST, immediate DB update, CSRF protected
A video, archive, or any file ≥ 100MB	TUS	Chunked, resumable, handles network failures
A file that needs to update a DB field after upload	Multipart	Response includes URL, persist via form.put()
A file that just needs to be stored and downloaded later	TUS	No DB update needed, async post-processing

Rule of thumb: if the file fits in a single POST and you need the URL back immediately, use multipart. If the file is ≥ 100MB or the upload might fail mid-way, use TUS.

Comparison

Factor	Multipart	TUS
File size	< 5MB	≥ 100MB (no hard limit)
Resumable	No	Yes
DB update needed	Yes (avatar URL)	No
CSRF	Yes	No (TUS has its own protocol)
Requests per upload	1 (POST)	3+ (POST, HEAD, PATCH…)
Endpoint	POST /app/upload	POST /tus/files
Auth	Session + CSRF	Session only

Storage layout

Both mechanisms write to storage/, but in different subdirectories:

storage/
├── avatars/              ← multipart uploads (avatars)
│   └── <userID>_<timestamp>.<ext>
├── uploads/              ← TUS internal format (by upload ID)
│   ├── <upload-id>
│   └── <upload-id>.info
└── completed/            ← TUS post-processed (original filenames)
    └── <original-name>

All files are served publicly via app.Static("/storage", "./storage").

Next

• Avatar upload — multipart FormData, CSRF, validation, two-step persistence
• TUS resumable upload — chunked uploads, retry, pause/resume, post-processing