# Batch Refactor With Sub Agents > Use a sub-agent (like `generalist`) to perform repetitive code transformations across multiple files in a single turn. Use when this capability is needed. - Skill: `tomevault-io/batch-refactor-with-sub-agents` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add tomevault-io/batch-refactor-with-sub-agents` - Raw SKILL.md: https://api.skillmd.com/api/skills/tomevault-io/batch-refactor-with-sub-agents/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: AI & ML - Author: tomevault-io (https://skillmd.com/u/tomevault-io) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tomevault-io/batch-refactor-with-sub-agents --- ## When to Use - Renaming symbols or updating function signatures across many files. - Migrating code from one pattern to another (e.g., manual error handling to a common helper). - Replacing literals with centralized constants across the codebase. - Performing any repetitive "find-and-replace" task that would otherwise require many sequential `replace` calls. ## Procedure 1. **Define the transformation**: Identify the exact "before" and "after" patterns. Create a representative code snippet for the sub-agent to follow. 2. **Locate targets**: Use `grep_search` to find all absolute file paths and line numbers that need modification. 3. **Draft a precise prompt**: Call the `generalist` (or similar) tool with a prompt that includes: - **Goal**: Clear statement of the refactoring objective. - **Scope**: A bulleted list of absolute file paths to modify. - **Example**: A code block showing the `old_string` vs `new_string` transformation. - **Constraints**: Instructions to preserve specific logic (e.g., "preserve original closure logic while changing the call site"). - **Verification**: Instructions to run `cargo check --all-targets` or specific tests after finishing. 4. **Delegate**: Execute the sub-agent call. 5. **Review and Cleanup**: Sub-agents may introduce minor issues like `unused_import` warnings. Perform a final sweep with `cargo clippy` and fix manually or via a second batch call. ## Pitfalls and Fixes - **symptom**: Sub-agent misses some files or applies incorrect logic. - **likely cause**: Prompt was too vague or the transformation was too complex for a single turn. - **fix**: Break the task into smaller, more homogeneous batches (e.g., "refactor all files in directory A first"). - **symptom**: `cargo check` fails after the sub-agent finishes. - **likely cause**: Sub-agent clobbered a symbol or messed up indentation/syntax. - **fix**: Read the modified files and use targeted `replace` calls to fix the syntax errors. ## Verification - Run `cargo check --all-targets` to confirm zero compilation errors. - Run `cargo clippy --all-targets` to find and fix any `unused_import` or style warnings introduced by the refactor. - Run relevant integration tests for the modified files. --- > Source: [r3bl-org/r3bl-open-core](https://github.com/r3bl-org/r3bl-open-core) — distributed by [TomeVault](https://tomevault.io).