Configuration

All configuration is done through environment variables. Every variable has a sensible default, so SnapOtter works out of the box without setting any of them.

Environment variables

Server

Variable	Default	Description
PORT	1349	Port the server listens on.
RATE_LIMIT_PER_MIN	0 (disabled)	Maximum requests per minute per IP. Set to 0 to disable rate limiting.
CORS_ORIGIN	(empty)	Comma-separated allowed origins for CORS, or empty for same-origin only.
LOG_LEVEL	info	Log verbosity. One of: fatal, error, warn, info, debug, trace.
TRUST_PROXY	true	Trust X-Forwarded-For headers from a reverse proxy. Set to false if not behind a proxy.

Authentication

Variable	Default	Description
AUTH_ENABLED	false	Set to true to require login. The Docker image defaults to true.
DEFAULT_USERNAME	admin	Username for the initial admin account. Only used on first run.
DEFAULT_PASSWORD	admin	Password for the initial admin account. Change this after first login.
MAX_USERS	0 (unlimited)	Maximum number of registered user accounts. Set to 0 for unlimited.
SESSION_DURATION_HOURS	168	Login session lifetime in hours (default is 7 days).
SKIP_MUST_CHANGE_PASSWORD	-	Set to any non-empty value to bypass the forced password-change prompt on first login

Storage

Variable	Default	Description
STORAGE_MODE	local	local or s3. Only local storage is currently implemented.
DB_PATH	./data/snapotter.db	Path to the SQLite database file.
WORKSPACE_PATH	./tmp/workspace	Directory for temporary files during processing. Cleaned up automatically.
FILES_STORAGE_PATH	./data/files	Directory for persistent user files (uploaded images, saved results).

Processing limits

Variable	Default	Description
MAX_UPLOAD_SIZE_MB	0 (unlimited)	Maximum file size per upload in megabytes. Set to 0 for unlimited.
MAX_BATCH_SIZE	0 (unlimited)	Maximum number of files in a single batch request. Set to 0 for unlimited.
CONCURRENT_JOBS	0 (auto)	Number of batch jobs that run in parallel. Set to 0 to auto-detect based on available CPU cores.
MAX_MEGAPIXELS	0 (unlimited)	Maximum image resolution allowed in megapixels. Set to 0 for unlimited.
MAX_WORKER_THREADS	0 (auto)	Maximum worker threads for image processing. Set to 0 to auto-detect based on available CPU cores.
PROCESSING_TIMEOUT_S	0 (no limit)	Maximum processing time per request in seconds. Set to 0 for no timeout.
MAX_PIPELINE_STEPS	0 (no limit)	Maximum number of steps in a pipeline. Set to 0 for no limit.
MAX_CANVAS_PIXELS	0 (no limit)	Maximum canvas size in pixels for output images. Set to 0 for no limit.
MAX_SVG_SIZE_MB	0 (unlimited)	Maximum SVG file size in megabytes. Set to 0 for unlimited.
MAX_LOGO_SIZE_KB	500	Maximum custom branding logo size in kilobytes.
MAX_SPLIT_GRID	100	Maximum grid dimension for the image split tool.
MAX_PDF_PAGES	0 (unlimited)	Maximum number of PDF pages for PDF-to-image conversion. Set to 0 for unlimited.

Cleanup

Variable	Default	Description
FILE_MAX_AGE_HOURS	72	How long temporary files are kept before automatic deletion.
CLEANUP_INTERVAL_MINUTES	60	How often the cleanup job runs.

Appearance

Variable	Default	Description
APP_NAME	SnapOtter	Display name shown in the UI.
DEFAULT_THEME	light	Default theme for new sessions. light or dark.
DEFAULT_LOCALE	en	Default interface language.

Docker permissions

Variable	Default	Description
PUID	999	Run the container process as this UID. Set to match your host user for bind mounts (id -u).
PGID	999	Run the container process as this GID. Set to match your host group for bind mounts (id -g).

Docker example

services:
  SnapOtter:
    image: snapotterhq/snapotter:latest
    ports:
      - "1349:1349"
    volumes:
      - SnapOtter-data:/data
      - SnapOtter-workspace:/tmp/workspace
    environment:
      - AUTH_ENABLED=true
      - DEFAULT_USERNAME=admin
      - DEFAULT_PASSWORD=changeme
      - MAX_UPLOAD_SIZE_MB=200
      - CONCURRENT_JOBS=4
      - FILE_MAX_AGE_HOURS=12
    restart: unless-stopped

Volumes

The Docker container uses two volumes:

• /data -- Persistent storage for the SQLite database and user files. Mount this to keep users, API keys, saved pipelines, and uploaded images across container restarts.
• /tmp/workspace -- Temporary storage for images being processed. This can be ephemeral, but mounting it avoids filling up the container's writable layer.