Gb Co Authored

Get all commits between the base branch and HEAD:

git log origin/<base>..HEAD --format="%H %ae %s"

Only process commits authored by the current user. Match by email ($MY_EMAIL) or by GitHub username ($MY_LOGIN). Skip all other commits — they belong to other contributors and must not be touched.

4. Check each of my commits for Co-Authored-By

For each of my commits, inspect the full message:

git log -1 --format="%B" <sha>

Check if it contains Co-Authored-By: Claude <[email protected]>.

Build two lists:

• OK: my commits that already have the trailer
• Missing: my commits that need it

If all my commits are OK, inform the user and stop.

5. Show the user what will be rewritten

## Commits missing Co-Authored-By

| # | SHA | Message |
|---|-----|---------|
| 1 | abc1234 | feat: add login page |
| 2 | def5678 | fix: handle null case |

These commits will be rewritten to add the trailer. This requires a force push.
Proceed?

Wait for user confirmation before proceeding.

6. Rewrite commits

Use git rebase with GIT_SEQUENCE_EDITOR to automate the rebase. For each commit that needs the trailer, change pick to reword:

GIT_SEQUENCE_EDITOR="sed -i 's/^pick <short_sha>/reword <short_sha>/'" \
  git rebase -i origin/<base>

Then for each reword step, use GIT_EDITOR to append the trailer to the commit message. Use an env-based editor script:

# Create a temporary script that appends the trailer if missing
cat > /tmp/add-coauthor.sh << 'SCRIPT'
#!/bin/bash
if ! grep -q "Co-Authored-By: Claude" "$1"; then
  echo "" >> "$1"
  echo "Co-Authored-By: Claude <[email protected]>" >> "$1"
fi
SCRIPT
chmod +x /tmp/add-coauthor.sh

GIT_SEQUENCE_EDITOR="sed -i -E 's/^pick (SHORT_SHAS_PIPE_SEPARATED)/reword \1/'" \
  GIT_EDITOR="/tmp/add-coauthor.sh" \
  git rebase -i origin/<base>

Replace SHORT_SHAS_PIPE_SEPARATED with the short SHAs of missing commits joined by | for the sed regex.

7. Force push

git push --force-with-lease

8. Verify

git log origin/<base>..HEAD --format="%H %s" 

Check all commits now have the trailer and report:

## Done

All N commits now have Co-Authored-By trailer.
Force pushed to origin/<branch>.

Rules

• ALWAYS ask for user confirmation before rewriting history
• ALWAYS use --force-with-lease instead of --force
• NEVER touch commits from other authors — only rewrite the current user's commits
• NEVER rewrite commits that already have the trailer
• NEVER change anything in the commit besides appending the trailer
• NEVER proceed without user confirmation — this is a destructive operation
• If rebase fails (conflicts), abort with git rebase --abort and inform the user