How I Cut My AI API Costs by 40% Without Changing a Single Prompt

Most developers overpay for AI by sending every query to the same model. Here's how intelligent routing across Anthropic, OpenAI, and Google saved me 40% on API costs. I was spending about $200 a month on Anthropic API calls. Building a product that makes a lot of AI requests — some complex, some dead simple. Every single call went to Claude Sonnet because it was "good enough" and I didn't want to deal with multiple providers. Then I sat down and actually looked at what those calls were doing. About 60-70% of my API calls were simple tasks. Summarise this paragraph. Extract the name from this email. Classify this support ticket. Translate this sentence. These don't need Sonnet. A model like Gemini Flash or Claude Haiku handles them perfectly at a fraction of the cost. The other 30% were genuinely complex — analysing financial data, generating reports, multi-step reasoning. Those needed a capable model. But I was paying Sonnet prices for the simple stuff just because I couldn't be bothe