How to test LLM integrations in CI without burning tokens

The problem nobody talks about Every tutorial on building with AI shows you the happy path: call the API, get a response, render it. Ship it. But here's what actually happens when you're building AI features for real: You write integration tests — they call OpenAI. That's real money on every test run. Your CI pipeline runs 20 times a day? That's 20× your token bill and you haven't even shipped a feature yet. Then there's the debugging loop. Something breaks in your response parsing logic. You tweak the code, hit the API, wait 3 seconds, read the response, realize the bug is elsewhere, tweak again. Every single iteration costs tokens and adds latency. You're paying to debug your own code, not even the AI part. And the worst part? AI responses are non-deterministic. Your test passes today, fails tomorrow, because the model decided to phrase something differently. Your CI goes red for no reason. You re-run it and it's green. Nobody trusts the test suite anymore. We hit this exact wall whi