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Upload Limits ​

SkySend provides several configuration options to control upload behavior.

Maximum File Size ​

The MAX_FILE_SIZE variable controls the maximum allowed upload size. It supports human-readable units:

bash
MAX_FILE_SIZE=2GB      # 2 gigabytes (default)
MAX_FILE_SIZE=500MB    # 500 megabytes
MAX_FILE_SIZE=100MB    # 100 megabytes

Supported units: B, KB, MB, GB

Reverse Proxy

If using a reverse proxy (Nginx, Caddy, etc.), make sure its upload size limit matches. For Nginx, set client_max_body_size.

Maximum Files Per Upload ​

When users upload multiple files, they are zipped client-side before encryption. The MAX_FILES_PER_UPLOAD variable limits the number of files per upload:

bash
MAX_FILES_PER_UPLOAD=32   # default
MAX_FILES_PER_UPLOAD=100  # allow more files

Note: MAX_FILE_SIZE applies to the total payload size (after zip, before encryption), not to individual files.

Expiry Options ​

Control which expiry times users can select:

bash
# Default: 5min, 1h, 1d, 7d
EXPIRE_OPTIONS_SEC=300,3600,86400,604800

# Custom: 1h, 12h, 1d, 3d
EXPIRE_OPTIONS_SEC=3600,43200,86400,259200

# Short-lived only: 5min, 15min, 1h
EXPIRE_OPTIONS_SEC=300,900,3600

The DEFAULT_EXPIRE_SEC must be one of the values in EXPIRE_OPTIONS_SEC.

Download Limits ​

Control which download limits users can select:

bash
# Default options
DOWNLOAD_OPTIONS=1,2,3,4,5,10,20,50,100

# Restrictive: 1-5 only
DOWNLOAD_OPTIONS=1,2,3,4,5

# Generous: allow up to 1000
DOWNLOAD_OPTIONS=1,5,10,50,100,500,1000

The DEFAULT_DOWNLOAD must be one of the values in DOWNLOAD_OPTIONS.

How Limits Are Enforced ​

  1. The frontend fetches server limits via GET /api/config on load
  2. Upload options in the UI are restricted to server-configured values
  3. The server validates all headers against configured limits during upload
  4. Uploads exceeding MAX_FILE_SIZE are rejected before writing to disk
  5. Content-Length header must match the actual body size