diff --git a/.claude/commands/README.md b/.claude/commands/README.md
index a819efc..1345527 100644
--- a/.claude/commands/README.md
+++ b/.claude/commands/README.md
@@ -12,6 +12,7 @@
 /git:cm         → Stage and commit (no push)
 /git:cp         → Stage, commit, and push
 /git:pr         → Create pull request
+/git:clean      → Delete merged branches (local + remote)
 ```
 
 ### Quality Gates
diff --git a/.claude/commands/git/clean.md b/.claude/commands/git/clean.md
new file mode 100644
index 0000000..ebb9c20
--- /dev/null
+++ b/.claude/commands/git/clean.md
@@ -0,0 +1,59 @@
+---
+description: Clean up merged branches locally and on remote, keeping only main, dev, and gh-pages.
+---
+
+Clean up stale branches that have been merged or are no longer needed.
+
+## Steps
+
+1. **List local branches** to delete (excluding `main`, `dev`, `gh-pages`):
+
+```bash
+git branch | grep -v -E '^\*|main$|dev$|gh-pages$'
+```
+
+Report what will be deleted. If no branches found, say "No local branches to clean" and skip to step 3.
+
+2. **Delete local branches** that are fully merged:
+
+```bash
+git branch -d <branch-name>
+```
+
+If a branch is not fully merged, report it to the user and ask whether to force-delete. Do NOT force-delete without confirmation.
+
+3. **List remote branches** to delete (excluding `main`, `dev`, `gh-pages`, `HEAD`):
+
+```bash
+git branch -r | grep -v -E 'origin/main$|origin/dev$|origin/gh-pages$|origin/HEAD'
+```
+
+Report what will be deleted. If no branches found, say "No remote branches to clean" and skip to step 5.
+
+4. **Confirm with the user** before deleting remote branches. Show the full list and wait for approval. Then delete:
+
+```bash
+git push origin --delete <branch-names>
+```
+
+5. **Prune stale remote refs**:
+
+```bash
+git remote prune origin
+```
+
+6. **Report final state**:
+
+```bash
+git branch        # local
+git branch -r     # remote
+```
+
+Present a summary:
+
+| Item | Count |
+|------|-------|
+| Local branches deleted | N |
+| Remote branches deleted | N |
+| Remaining local | main, dev |
+| Remaining remote | origin/main, origin/dev, origin/gh-pages |