diff --git a/skills/refactor/SKILL.md b/skills/refactor/SKILL.md
new file mode 100644
index 0000000..ec1f105
--- /dev/null
+++ b/skills/refactor/SKILL.md
@@ -0,0 +1,68 @@
+---
+name: refactor
+description: >
+  Refactor every file that is currently uncommitted in the git working tree -
+  staged, unstaged and untracked - up to the project's coding standards,
+  without changing behaviour. Trigger on /refactor or when the operator asks to
+  clean up, tidy, or polish the current changes before committing. Portable
+  across projects.
+---
+
+The unit of work is the uncommitted change set, not the repository. Behaviour
+stays identical: a refactor that changes what the code does is a bug, not a
+cleanup.
+
+## Step 1: fix the file set
+
+Read the set from git, never from memory of what was edited:
+
+```bash
+git status --porcelain
+```
+
+Take modified, added, renamed and untracked files. Drop deleted files, binaries,
+lockfiles, vendored trees and generated output. Restate the resulting list in
+one line before touching anything; if it is empty, say so and stop.
+
+Never `git stash` and never revert a working-tree file to compare - other agents
+and the operator share this tree. Read the committed version with
+`git show HEAD:<path>` into a temporary file instead.
+
+## Step 2: refactor each file
+
+Read the whole file first, then apply the standards that the surrounding code
+and the project's own config already establish (formatter config, linter rules,
+existing idioms) over any generic preference of your own:
+
+- **Duplication**: fold repeated logic into the helper that already exists;
+  create a new one only when two or more call sites need it now.
+- **Dead weight**: unused imports, variables, parameters, branches that cannot
+  be reached, flags with a single value, abstractions with one implementation.
+- **Naming**: names that state what a thing is, matching the file's convention.
+- **Shape**: split a function that needs a scroll to read; collapse nesting by
+  returning early; replace magic values with a named constant at its use site.
+- **Errors**: never widen a caught exception, never swallow one, never remove a
+  validation or a security check to make the code shorter.
+- **Comments**: invoke the `comments-clean` skill rather than reimplementing its
+  rules here.
+
+Do not reformat regions you have no substantive fix for - cosmetic churn buries
+the real change in the diff. If a file's problem is architectural and cannot be
+fixed inside the change set, report it instead of half-doing it.
+
+## Step 3: keep behaviour provable
+
+- Never fold a bug fix, a feature, or a dependency change into a refactor.
+  Found a real bug? Name it in the report and leave it for a separate change.
+- Run the cheap checks the project already has for the touched files (formatter,
+  linter, the module's own unit tests). Do not start a full suite, a build, or a
+  deploy on your own initiative - propose it and let the operator trigger it.
+- State plainly what was verified and what was not. An unverified refactor is
+  reported as unverified.
+
+## Step 4: report
+
+One line per file: what changed and why it is safe. Then one line naming what
+was deliberately left alone (architectural findings, bugs, files skipped) and
+the exact command the operator can run to validate. Do not commit unless the
+operator asked for a commit.