Does Claude Code respect the “no vendor edits” Magento rule?

Yes — we encode this as a top-level rule in CLAUDE.md with explicit examples: “Never modify vendor/. Always extend via plugins, observers, di.xml preferences, or theme overrides. Reads are fine, writes are forbidden.” Claude Code reads vendor for context (which is critical for understanding extension points) but writes only into app/code/, themes, and your project root. Every PR is checked for vendor-path writes via a pre-commit hook — commits that touch vendor are blocked at git level.