Paths: File paths (

shared/

,

references/

,

../ln-*

) are relative to skills repo root. If not found at CWD, locate this SKILL.md directory and go up one level for repo root.

ln-831-oss-replacer

Overview

docs/project/codebase_audit.md

Workflow

Phase 0: Pre-flight Checks

shared/references/ci_tool_detection.md

Worktree & Branch Isolation

shared/references/git_worktree_fallback.md

Phase 1: Load Migration Plan

From Audit Report

docs/project/codebase_audit.md

From Target Module

shared/references/research_tool_fallback.md

Phase 2: Prioritize Replacements

Phase 3: Replace Loop (Keep/Discard)

Per-Module Cycle

FOR each replacement candidate (R1..RN):
  1. INSTALL: Add OSS package
     npm install {package} / dotnet add package / pip install
  2. REWRITE: Update imports + call sites using api_mapping
  3. VERIFY: Run tests
     IF tests FAIL → DISCARD (revert ALL: uninstall package, restore files) → next
  4. TESTS PASS → KEEP
  5. DELETE: Remove old custom module (only after keep)
  6. LOG: Record replacement for report

Atomic Revert on Discard

npm uninstall

dotnet remove package

pip uninstall

git checkout -- {modified_files}

git checkout -- {lock_file}

Safety Rules

Phase 4: Report Results

Report Schema

Configuration

Options:
  # Source
  audit_report: "docs/project/codebase_audit.md"
  target_module: ""

  # Confidence
  min_confidence: "MEDIUM"      # MEDIUM | HIGH

  # Verification
  run_tests: true

  # Safety
  require_test_coverage: true   # Skip modules with no tests
  delete_old_module: true       # Delete custom module after successful replacement

Error Handling

References

• ../ln-645-open-source-replacer/SKILL.md

  (companion: finds candidates)

• shared/references/ci_tool_detection.md

  (test detection)

• shared/references/research_tool_fallback.md

  (MCP tool chain)

Definition of Done

• Migration plan loaded from audit report or target module analyzed
• Candidates prioritized by confidence + LOC
• Each replacement applied atomically: install → rewrite → test → keep/discard
• Discarded replacements fully reverted (package + files + lock)
• Kept replacements: old custom module deleted
• Report returned with candidates total, applied, discarded, LOC removed