Code Refactor with Diff and Rationale

Choose this endpoint when you need both a concrete diff and a human-readable rationale explaining refactoring decisions — not just a rewritten version. It's particularly useful for preparing code review materials, documenting technical debt cleanup, or understanding why changes were made. Prefer it over a generic code completion endpoint when behavioral preservation and auditability are the priority.

• Code snippet is too large or complex for the model context window
• Ambiguous or mixed-language snippets may produce incorrect diffs
• If the code has side effects that are hard to detect, behavioral preservation cannot be fully guaranteed
• Malformed or unparseable code may cause an empty or incorrect diff
• Model may occasionally hallucinate changes that subtly alter behavior in edge cases