| My OpenAI bills were getting out of hand - I was using GPT-4 for everything, even simple tasks that GPT-3.5 could handle
perfectly. So I built CostLens. It's a drop-in replacement that automatically routes requests to cheaper models when possible, but falls
back to premium ones when quality matters. How it works:
js
// Just swap this:
const openai = new OpenAI({ apiKey: 'sk-...' }); // For this:
const costlens = new CostLens();
const openai = costlens.openai({ apiKey: 'sk-...' });
// Everything else stays exactly the same Real savings:
• Simple tasks: GPT-4 → GPT-4o-mini (95% cheaper)
• Complex tasks: Still uses GPT-4 when needed
• My bills dropped ~70% with zero code changes Features:
• Quality detection (auto-retries with better models if response is bad)
• Works with existing code - no prompt changes needed
• Caching with Redis
• Instant mode (no signup required) Try it: npm install costlens The core SDK is free and works locally. I'm also building a dashboard for teams to track their AI spending. NPM: https://www.npmjs.com/package/costlens Anyone else tired of overpaying for AI APIs? What's your biggest cost pain point? |
I'm the dev behind this. Started as a weekend project because I kept getting sticker shock from my OpenAI bills. I'd use GPT-4 for literally everything - even "fix this typo" type requests that cost 20x more than they should.
The breakthrough was realizing most requests don't actually need the expensive models. So I built quality detection that tries the cheap model first, then upgrades only if the response is garbage.
Been using it in production for 3 months now. Went from ~$400/month to ~$120/month with zero changes to my actual prompts or code. The quality detection catches about 15-20% of requests that need the premium models.
Works with both OpenAI and Anthropic - Claude Opus → Claude Haiku saves even more than the OpenAI routing since the price gap is bigger.
Happy to answer any questions! The trickiest part was getting the quality scoring right - too aggressive and you get bad responses, too conservative and you don't save money.
Also working on a team dashboard, but wanted to get the core SDK out there first since it's been so useful for me.