How I Made Claude Code Auto-Fix Breaking API Changes in CI

AI coding assistants are great at generating code. But what happens when the code they generate breaks your API contract? I built a workflow where Claude Code reads structured CI output, understands the breaking change, and fixes it — automatically. The Problem If you have an OpenAPI spec checked into your repo, there's a good chance nobody is actually reviewing it on pull requests. Linters like Spectral validate the spec in isolation, but they don't compare old vs. new. They'll catch a missing description, but not the fact that you just changed a response field from string to integer — the kind of change that breaks every downstream consumer. I needed something that would: Diff the spec against the base branch on every PR Classify each change as breaking or non-breaking Tell me the exact semver impact Give me a migration guide so I could fix it fast The Solution: Delimit GitHub Action I built Delimit , a GitHub Action that does all of this deterministically. No LLM in the loop, no ext