Most of your Claude Code agents don't need Sonnet

I run about 50 Claude Code agent calls a day. Only 8 of them need the expensive model. The rest? They're writing commit messages, reviewing diffs, running tests, generating docs. Tasks that don't require deep reasoning — just reliable pattern matching. And yet, by default, every single one of those calls hits the same model at the same price. Here's how I fixed that with a 3-tier routing strategy that sends each task to the cheapest model that can handle it. The problem: one model fits none Claude Code's agent system is powerful. You can spin up subagents for code review, testing, commits, debugging — the works. But out of the box, they all use the same model. That's like paying a senior architect to format your README. The fix isn't complicated. You just need to match the model to the task. The 3-tier model strategy I run 17 agents across my development workflow. Here's how they break down: Tier 3: Sonnet (full reasoning) → 8 agents (32%) Tier 2: Haiku (fast + cheap) → 17 agents (68%)