I signed up for a free-tier LLM API, hit a credit-card prompt before I'd made a single call, and assumed it meant I was about to get billed. I was wrong about that one. I was not wrong that the SDK code I wrote next would break twice before I got a real response back. TL;DR: Sakura AI Engine's free tier (3,000 chat completions/month, hosting OpenAI's open-weight gpt-oss-120b ) broke 3 assumptions in a row: that a credit-card prompt on a free plan means billing, that Anthropic's Python SDK a...