undo-commit

Reverses one commit without losing the work. Equivalent to git reset --soft HEAD~1 with safety guards.

Pre-flight

git rev-parse --is-inside-work-tree

If not in a git repo, stop:

not a git repo. /undo-commit requires a git repository.

Verify HEAD has a parent (can't undo the initial commit):

git rev-parse HEAD^ 2>/dev/null

If this fails: refused: HEAD is the initial commit. nothing to undo.

Verify HEAD is not a merge commit (undoing a merge is destructive in a non-obvious way — bounce to the user):

git rev-list --parents -n 1 HEAD | awk '{print NF-1}'

If output >= 2: refused: HEAD is a merge commit. use git reset --hard ORIG_HEAD manually if you understand the consequences.

Verify HEAD is not already on the remote (cannot soft-undo a published commit without rewriting public history):

git rev-parse --abbrev-ref --symbolic-full-name @{u} 2>/dev/null

If a tracking branch exists, check whether HEAD is reachable from upstream:

git merge-base --is-ancestor HEAD @{u}

If exit 0 (HEAD already on remote): refused: HEAD is already pushed to <upstream>. /undo-commit only undoes local commits. use git revert <sha> for a published commit.

Confirm

Show what's about to be undone:

git log -n 1 --format='  %h %s%n  %an, %ar%n%n  Files:%n' HEAD
git diff --stat HEAD^..HEAD

Ask via AskUserQuestion:

Undo this commit? Changes will be moved back to the staging area.
- Yes, undo
- No, keep it

On No: print kept. and stop. No action.

Action

On Yes:

git reset --soft HEAD~1

Report

Print:

undone. HEAD now at <new-sha-short>.
prior commit's changes are staged. inspect with: git status, git diff --cached
to re-commit: /commit
to discard: git restore --staged <paths> then git restore <paths>

Rules

• --soft only. Never --mixed, never --hard. The user's work stays in the index where it's visible and recoverable.
• Refuse on initial commit, merge commit, or pushed HEAD. These cases need human judgment.
• One commit per invocation. To undo multiple, run again — the per-invocation confirm forces deliberate steps.
• Print every git command before running it.
• Do not stage, do not commit, do not push. After git reset --soft, control returns to the user.
• This is the only command that mutates history. Treat it as destructive (axiom 3) — never act without the per-item Yes.