git-author-rewrite

name

git-author-rewrite

description

Rewrite all commit authors and committers in a git branch or repository history to a new name/email combination. Use this skill whenever the user mentions changing git commit authors, rewriting git attribution, mass updating committer info, fixing author names/emails across a branch history, or wants to correct commit attribution for an entire repo. Trigger even if the user doesn't explicitly mention "git-author-rewrite" or uses casual phrases like "change who wrote these commits" or "update my email on all past commits".

git-author-rewrite

Rewrite all commit authors in a git branch to a new name/email combination. Useful for correcting attribution across an entire branch history.

Workflow

1. Get current context

# Get repo URL and current branch
git remote get-url origin
git branch --show-current

2. Clone to /tmp/ for safe rewriting

Never rewrite in-place. Always work on a clone:

git clone <repo-url> /tmp/<repo>-rewrite
cd /tmp/<repo>-rewrite
git checkout <branch>

3. Rewrite all commit authors

Use git filter-branch with --env-filter to update both author and committer:

cd /tmp/<repo>-rewrite
git filter-branch --env-filter '
GIT_AUTHOR_NAME="New Name"
GIT_AUTHOR_EMAIL="[e-mail]"
GIT_COMMITTER_NAME="New Name"
GIT_COMMITTER_EMAIL="[e-mail]"
' -- --all

Notes:

• --all rewrites all branches and tags
• The env-filter sets both author and committer to ensure consistency
• WARNING about git-filter-branch is normal; it's acceptable for this use case

4. Verify the rewrite

Check that authors were updated correctly:

git log --format="%h %an <%ae> %s" | head -10

5. Clean up filter-branch artifacts

Remove backup refs and repack:

git for-each-ref --format='%(refname)' refs/original/ | xargs -n 1 git update-ref -d 2>/dev/null
git reflog expire --expire=now --all
git gc --prune=now

6. Apply to original repo (optional, not automatic)

If user wants to replace their local repo:

cd <original-repo>
git remote add rewritten /tmp/<repo>-rewrite
git fetch rewritten
git reset --hard rewritten/master

Important constraints

• Never push unless explicitly asked
• Always work on a clone in /tmp/ to avoid corrupting the working directory
• Verify before applying - once rewritten, commits have new hashes
• This rewrites history - all commit SHAs will change
• Team members will need to re-clone or reset if this is pushed to shared branches

Example

User: "change the author of every commit in this branch to user name Dario clavijo email [e-mail]"

Agent:

1. Gets repo URL and branch name
2. Clones to /tmp/ImpactGuard-rewrite
3. Runs filter-branch with the new author info
4. Verifies with git log
5. Cleans up backup refs
6. Informs user the rewritten repo is at /tmp/ImpactGuard-rewrite and explains how to apply it