How I Track My AI Spending as a Solo Dev (Without Going Broke)

I ship solo. No team, no finance department, no one reviewing expenses but me. When I started using LLMs heavily in my workflow — Claude for code review, GPT for drafts, a bit of Gemini here and there — I told myself I'd keep a close eye on costs. I had a vague sense of what I was spending. Turns out "a vague sense" doesn't cut it when you're getting invoiced. So I built a system. Or rather, I cobbled one together after getting burned. The Moment That Changed How I Think About This I was three weeks into a heavy coding sprint. I had Claude open basically all day — asking it to review diffs, explain errors, help me write tests. Normal stuff. Then my monthly statement hit. Not catastrophic, but more than I'd mentally budgeted. The frustrating part wasn't the money. It was that I had zero visibility while it was happening. I couldn't have told you whether I'd spent $5 or $50 that day. There was no real-time signal. Just vibes, then an invoice. That's when I started treating AI spending li