Yes—Claude Opus 4.6 can handle multi-file refactors safely if you enforce an incremental patch strategy and require verification at each step. Multi-file refactors are risky because they involve hidden coupling and require coordinated changes across interfaces and call sites. Opus 4.6 is positioned as strong at coding, code review, and sustained agentic work, which makes it well-suited for refactor workflows—provided you don’t let it do a sweeping rewrite in a single, unreviewable diff.
A safe refactor playbook looks like this:
Inventory: ask the model to list affected files, symbols, and call paths before editing.
Constraints: define invariants (“public API unchanged,” “no new deps,” “performance unchanged”).
Small diffs: limit each patch to a bounded number of files and lines.
Verification: run unit tests, lint, typecheck; feed failures back.
Stop conditions: cap iterations and require human review for risky areas (auth, crypto, persistence).
Require the model to output a unified diff plus a short “why this is safe” explanation and a test plan (exact commands). Then apply the diff in a sandbox, run checks, and only then consider merging. The safety comes from the system: guardrails + tests + review.
If your refactor must follow architectural rules, retrieval makes it much more consistent. Put your architecture docs, module boundaries, and migration guides into Milvus or Zilliz Cloud. Retrieve the relevant constraints for the modules being refactored and include them in the prompt as the authoritative rules. This reduces the common failure mode where refactors “work” but violate layering or style conventions. With Opus 4.6, the best results happen when it has the right evidence and a verification loop that forces correctness.