My Discord bot has one job: when someone pastes a stack trace into our server's #help channel, it rewrites the trace into a plain-English explanation plus a likely fix. It ran for months on a paid LLM API at a few dollars a month — small money, but the kind that nags you when the workload is trivially bursty: silent for days, then thirty requests in an evening when a game update breaks everyone's mods. So I pointed it at a free endpoint instead. The migration took an afternoon. The consequen...