Remove Deadcode

Remove Dead Code

Delete code that is provably unreferenced — without breaking anything. The rule is simple: prove it's dead before you delete it. A confident-looking unused symbol is often reached through a barrel export, a test, reflection, or a framework entry point. Verify first. For behavior-preserving complexity reduction (simplify without deleting), use the simplify skill.

Phase 1: Scan (parallel)

Fire independent detectors at once and collect candidates:

• Compiler / linter unused flags — e.g. TypeScript tsc --noUnusedLocals --noUnusedParameters, ESLint no-unused-vars, Go deadcode/staticcheck, Python vulture, Rust cargo +nightly udeps / dead-code warnings.
• Orphaned files — source files not imported by any other file.
• Unused exports — exported symbols never imported elsewhere.
• LSP references — "find all references" returning only the definition.

Delegate broad searches to explore subagents in parallel when the codebase is large; keep each search scoped to one question.

Phase 2: Verify each candidate (before deleting)

For every candidate, confirm it is genuinely dead. Discard it (keep the code) if any of these is true:

• It is re-exported through a barrel/index file that external code imports.
• It is referenced by tests, fixtures, or snapshots.
• It is a framework/tooling entry point (route handler, CLI command, migration, plugin hook, main, serializer) discovered by convention, not import.
• It is reached by reflection, dynamic import, string key, or DI container.
• It is part of a published public API (@public, exported package surface).

Re-run "find references" (LSP) immediately before each edit — the graph may have changed as you removed earlier items.

Phase 3: Delete in conflict-free batches

• Group removals by file: everything in the same file goes in the same batch, so parallel edits never collide.
• Remove the symbol/file and its now-unused imports.
• Stage precisely: git add <specific files> — never git add -A.

Phase 4: Prove the removal is safe

After each batch:

1. Build / type-check the project.
2. Run the test suite (or the affected subset).
3. Re-run the unused-symbol detector — the count should drop, not grow.

If the build or tests break, revert that batch and re-verify Phase 2 for the offending item.

Anti-patterns

• Deleting on a hunch without a references check.
• Bulk-deleting a whole directory because "it looks unused."
• Using git add -A and sweeping up unrelated changes.
• Removing something only reachable from tests, then deleting the tests too to make it look unused — that hides regressions.

Report

List what was removed and the evidence it was dead:

- removed <file/symbol> — <how it was proven unused: no importers / LSP 0 refs / linter>

End with the build + test result so the caller can trust the change.