gproxy on Zeabur

Recommended settings:

• GPROXY_ADMIN_KEY=your-strong-key
• GPROXY_HOST=0.0.0.0
• GPROXY_PORT=8787
• GPROXY_DATA_DIR=/app/data

Optional:

• GPROXY_DSN=sqlite:///app/data/db/gproxy.db
• GPROXY_PROXY=http://proxy:port

Persist /app/data to keep database and usage data.