If you have an Anthropic API key (from console.anthropic.com), you can paste it into Settings → AI. The app sends classification requests directly to Anthropic using your key — your traffic, your bill, our servers see nothing.
BYOK gives you every AI feature at zero cost to FocusDragon. You pay Anthropic's per-token rate (very cheap for the short classifier prompts we send).
BYOK does NOT include FocusDragon Pro features (Statistics, Locked blocks, Bulletproof Strictness). Those require the $5 Pro unlock or an AI subscription. BYOK and Pro are independent.