Last Tuesday, my free endpoint returned a valid JSON contract. The next call returned a summary. Same prompt. Same model label. No version bump. I almost merged code that expected a schema and instead got a paragraph.
Free tiers are not the enemy. Silent drift is.
When you wire a free AI server into your PR pipeline, you accept three facts: shared compute, changing model configs, and zero guarantee. So you need gates that fail closed. This is the checklist I now run before any AI-generated suggestion touches a merge branch.
I built these gates against an open-source gateway called MonkeyCode. Why? It gives solo devs free model access and a free server for trial workloads. Disclosure: This article was prepared as part of MonkeyCode's product outreach. Convenient, yes. Safe by default? No. So I test every claim.
Gate 1: Pin the response contract
