How to Safely Use AI Agents for Code Refactoring

AI refactoring agents — tools that rename variables, extract functions, reorganize modules, update imports, and restructure codebases — touch every file in a project and can silently introduce bugs through incorrect transformations, break build systems, or accidentally delete code during file reorganization. SafeClaw by Authensor makes refactoring agents safe by enforcing scope-limited write permissions, mandatory test-gate verification after each transformation, and complete audit trails that enable instant rollback if a refactoring goes wrong. Install with npx @authensor/safeclaw and refactor with confidence.

The Refactoring Agent Risk Profile

Refactoring is uniquely risky because it modifies working code. The agent must change many files while preserving exact behavior:

  ┌──────────────────────────────────────────────────┐
  │  REFACTORING AGENT RISKS                          │
  │                                                    │
  │  Scope Creep:                                      │
  │  └─ Agent refactors beyond the requested scope,    │
  │     touching files that weren't supposed to change │
  │                                                    │
  │  Silent Behavior Change:                           │
  │  └─ Renamed variable has different semantics       │
  │     in a different context, breaking logic         │
  │                                                    │
  │  Incomplete Transformation:                        │
  │  └─ Agent renames 95% of references, misses 5%,   │
  │     code compiles but runtime errors occur         │
  │                                                    │
  │  Build System Breakage:                            │
  │  └─ Module reorganization breaks import paths,     │
  │     webpack configs, or test configurations        │
  │                                                    │
  │  Accidental Deletion:                              │
  │  └─ Agent "cleans up" code by removing what it     │
  │     thinks is dead code, but isn't                 │
  └──────────────────────────────────────────────────┘

SafeClaw Policy for Refactoring Agents

# safeclaw-refactor-agent.yaml
version: "1.0"
agent: refactoring
rules:
  # === FILE READS (broad access needed for refactoring) ===
  - action: file_read
    path: "src/**"
    decision: allow
  - action: file_read
    path: "tests/**"
    decision: allow
  - action: file_read
    path: "package.json"
    decision: allow
  - action: file_read
    path: "tsconfig.json"
    decision: allow
  - action: file_read
    path: "*/.env"
    decision: deny
  - action: file_read
    path: "*/secret*"
    decision: deny
  - action: file_read
    decision: deny

# === FILE WRITES (scoped to refactoring target) ===
  - action: file_write
    path: "src/**"
    decision: allow
  - action: file_write
    path: "tests/**"
    decision: allow   # Tests may need import path updates
  - action: file_write
    path: "package.json"
    decision: deny    # No dependency changes during refactoring
  - action: file_write
    path: ".github/**"
    decision: deny    # No CI/CD changes
  - action: file_write
    path: "*/.config.*"
    decision: deny    # No config file changes
  - action: file_write
    decision: deny

# === TEST VERIFICATION (mandatory after each transformation) ===
  - action: shell_execute
    command: "npm test"
    decision: allow
  - action: shell_execute
    command: "npx tsc --noEmit"
    decision: allow
  - action: shell_execute
    command: "npm run lint"
    decision: allow
  - action: shell_execute
    command: "npm run build"
    decision: allow
  - action: shell_execute
    decision: deny

# === FILE DELETION ===
  - action: file_delete
    path: "src/**"
    decision: require_approval  # Human must approve file deletions
  - action: file_delete
    decision: deny

# === NETWORK ===
  - action: network_request
    decision: deny

The Test-Gate Pattern

The most important safety pattern for refactoring agents: require the agent to run tests after every transformation and halt if tests fail:

refactoring_workflow:
  test_gate:
    after_each_file: false        # Too slow for large refactors
    after_each_transformation: true # Run tests after each logical change
    command: "npm test"
    on_failure: rollback_last_transformation
    max_consecutive_failures: 2   # Halt after 2 failed attempts

  ┌────────┐     ┌──────────┐     ┌───────────┐     ┌────────┐
  │ Read   │────▶│ Transform│────▶│ Test Gate │────▶│ Next   │
  │ Code   │     │ Code     │     │ (npm test)│     │ Step   │
  └────────┘     └──────────┘     └─────┬─────┘     └────────┘
                                        │
                                   FAIL │
                                        ▼
                                  ┌───────────┐
                                  │ Rollback  │
                                  │ Last      │
                                  │ Transform │
                                  └───────────┘

Scope Limiting

Prevent the refactoring agent from touching files outside the requested scope. If the user asks to refactor src/utils/, the agent should not modify src/core/:

# Dynamic scope restriction
refactoring_scope:
  directories:
    - "src/utils/**"
  max_files_modified: 20          # Hard cap on modified files
  max_lines_changed_per_file: 500 # Flag excessive changes
  on_scope_exceeded: halt_and_report

Rollback-Ready Audit Trail

SafeClaw's hash-chained audit log records every file modification with the original content hash, enabling precise rollback:

{
  "timestamp": "2026-02-13T15:30:00Z",
  "action": "file_write",
  "path": "src/utils/helpers.ts",
  "original_hash": "sha256:abc123...",
  "new_hash": "sha256:def456...",
  "transformation": "rename_variable",
  "details": "oldName -> newName",
  "agent": "refactoring",
  "entry_hash": "sha256:..."
}

If the refactoring goes wrong, the audit trail shows exactly which files were modified and their original state, making rollback straightforward. Combined with git, this provides a complete safety net.

Cumulative Change Limits

Prevent the agent from making too many changes in a single session:

limits:
  max_files_modified: 30
  max_total_lines_changed: 5000
  max_file_deletions: 5
  max_session_duration: "30m"
  on_limit_exceeded: halt_and_report

SafeClaw's 446 tests cover refactoring scenarios, and the tool works with Claude and OpenAI under MIT license. Its zero-dependency architecture means the safety layer itself does not interfere with build processes or test runners.

Cross-References

• Code Review Agent Recipe
• Safe Autonomous Coding Agents
• Rollback AI Agent Changes Workflow
• Staging Environment for AI Workflow