$ man model-selection
Engineering · AI Agents
Model Selection
Choosing which AI model to use based on task complexity and cost.
why it matters
Opus is smarter but expensive. Sonnet is fast and cheap. For simple tasks (reformatting, scanning), use Sonnet. For complex reasoning (architecting, debugging), use Opus. Wrong model = wasted money or bad output.
how you use it
The daily tracker logs model usage. Opus sessions cost $12-15. Sonnet sessions cost $3-5. Track your spend. Optimize your model picks. Don't use Opus to count words.
related terms