How I Cut AI API Costs by 45x With a Simple Routing Proxy

Last week I ran a simple test. I sent "Say hi" to two different AI APIs. Claude/OpenAI cost: $0.000179 Through my routing proxy: $0.000004 Same response quality. 45x price difference. The insight I analyzed a month of API traffic from a production app. Here's what I found: 72% of requests were simple tasks: classification, extraction, summarization, translation 18% were medium: multi-step analysis, moderate code generation 10% were genuinely hard: complex reasoning, system design, novel code The simple tasks ran identically on DeepSeek V4 at $0.14/M tokens. We were paying Claude $15/M for the same work. That's a 100x markup on commodity tasks. The solution I built an OpenAI-compatible proxy that classifies each request and routes to the cheapest capable model: Complexity Model Cost/M tokens Simple (~70%) DeepSeek V4 $0.14 / $0.28 Medium (~20%) DeepSeek R1 $0.55 / $2.19 Hard (~10%) Claude Sonnet $3.00 / $15.00 The classifier itself uses DeepSeek (cost: ~$0.001 per classification). If a