Configuration

All configuration is done through environment variables, typically set in your docker-compose.yaml.

Environment Variables

Variable	Required	Default	Description
`JWT_SECRET`	Yes	—	Long random string (≥ 64 chars). Changing it invalidates all active sessions.
`PORT`	No	`3000`	TCP port the server listens on.
`DATA_DIR`	No	`./data`	Path to persistent data (books, covers, fonts, database).
`CORS_ORIGIN`	No	(same-origin)	Allowed CORS origin, e.g. `https://books.example.com`.

environment:
  JWT_SECRET: "your_very_long_random_secret_here"
  PORT: 3000
  DATA_DIR: /data
  CORS_ORIGIN: https://books.example.com

Important: Never commit your JWT_SECRET to version control.