Configuration

Trelay is configured via environment variables. Use a .env file in the project root (or set variables in your shell or Docker). The app loads .env automatically when present.

Required variables

Variable	Description
API_KEY	Secret used to authenticate API requests and dashboard login. Use a long random string (e.g. openssl rand -hex 32).
JWT_SECRET	Secret used to sign JWT tokens. Use a long random string. Keep it private.

Server

Variable	Description	Default
SERVER_HOST	Bind address	0.0.0.0
SERVER_PORT	HTTP port	8080
SERVER_READ_TIMEOUT	Read timeout (e.g. 10s)	10s
SERVER_WRITE_TIMEOUT	Write timeout (e.g. 30s)	30s
SERVER_SHUTDOWN_TIMEOUT	Graceful shutdown timeout	10s

Database

Variable	Description	Default
DB_DRIVER	sqlite3 or postgres	sqlite3
DB_PATH	SQLite database file path (used when DB_DRIVER=sqlite3)	trelay.db
DB_URL	PostgreSQL connection string (when DB_DRIVER=postgres)	—
DB_MAX_CONNS	Max DB connections (Postgres)	10

Authentication

Variable	Description	Default
TOKEN_EXPIRY	JWT token lifetime (e.g. 24h)	24h

Application

Variable	Description	Default
BASE_URL	Public URL for short links (e.g. https://links.example.com)	http://localhost:8080
DEFAULT_DOMAIN	Default domain for new links (optional)	—
CUSTOM_DOMAINS	Comma-separated list of allowed custom domains	—
STATIC_DIR	Path to frontend build output (serve SPA from server)	—
ANALYTICS_ENABLED	Enable click tracking	true
IP_ANONYMIZATION	Anonymize IP addresses in analytics	true
SLUG_LENGTH	Default length for auto-generated slugs (4–32)	6
MAX_URL_LENGTH	Maximum length of original URLs	2048
RATE_LIMIT_PER_MIN	API rate limit (requests per minute per client)	100

Example .env

# Required
API_KEY=your_secure_api_key_here
JWT_SECRET=your_secure_jwt_secret_here

# Server
SERVER_PORT=8080

# Database (SQLite)
DB_DRIVER=sqlite3
DB_PATH=trelay.db

# Public URL for short links
BASE_URL=https://links.example.com

# Optional
ANALYTICS_ENABLED=true
IP_ANONYMIZATION=true
RATE_LIMIT_PER_MIN=100