Optimizing API Costs: Strategic Use of Claude and Open Source Models
The first time I really paid attention to my AI API bill, I'd been running the ACP Agent for about two weeks. The number wasn't catastrophic, but it was on a trajectory that would've been catastrophic by month-end if I hadn't noticed. The problem wasn't the project. The problem was that I'd been using the most expensive model for every task — including tasks a much cheaper model could handle perfectly. Categorizing logs, formatting strings, summarizing structured data: all of these were running through the premium tier when they didn't need to. API costs are the silent leak in AI-native development. They don't break anything, they don't show up as errors, and they only become a problem once they're already a problem. What This Post Covers The strategies I use to keep AI API costs predictable across production projects: matching models to tasks, designing prompts that don't waste tokens, caching aggressively where it makes sense, and...