Which AI should I use?

Bricklayer does not come with its own AI. You bring one, and Bricklayer drives it safely against your game. During setup you choose between Claude Code, Codex, Gemini, and Bricklayer chat (which uses an OpenRouter key).

Decide in 30 seconds

The free options, honestly

Every free option has a limit. That is normal, and it is fine for learning and small games.

• OpenRouter free models. Easiest start. Capped at 20 requests a minute, and 50 a day on a zero balance.
• Codex on a free ChatGPT account. Good for short, focused sessions. Uses a rolling 5-hour window plus a weekly cap. Choose the ChatGPT sign-in, not the API key option, which is a paid path.
• Antigravity CLI. The most capable free agent, with weekly rate limits. Open your Bricklayer project folder in it; Bricklayer syncs what it writes.
• Ollama. No limits and fully private, but slower and weaker on multi-file work, and it needs a strong computer.

The full comparison, including setup steps and what each is good at, lives in Build without paying for AI.

Can I switch later?

Yes. Run Bricklayer: Choose AI Agent (Ctrl+I) to change your AI or model at any time. Your game and project do not change when you switch.

Does the AI choice change what it can do?

All of them work through the same Bricklayer tools, approvals, and diffs. Stronger models plan better and need fewer retries on bigger features. Smaller free models do best with small, specific requests. See Write prompts that get good results.