Remove Co-Authored-By from Commits

Remove Co-Authored-By from Commits

By default, Claude Code appends a Co-Authored-By trailer to every commit it creates:

Co-Authored-By: Claude <noreply@anthropic.com>

Here are four ways to remove it, from simplest to most automated.

Option 1: Claude Code Setting (Recommended)

Claude Code has a built-in setting to disable the trailer. Add this to your settings file:

{
  "includeCoAuthoredBy": false
}

Where to add it:

• Global (all projects): ~/.claude/settings.json
• Project (shared with team): .claude/settings.json
• Local only (not committed): .claude/settings.local.json

This is the cleanest solution — no hooks, no prompt instructions, just a single setting.

Option 2: Add a CLAUDE.md Instruction

Add this line to your project's CLAUDE.md:

Do not include a Co-Authored-By line in commit messages.

Claude Code reads CLAUDE.md before every task and will follow this instruction when creating commits.

Scope options:

• Per-project: Add to CLAUDE.md in your repo root
• Global: Add to ~/.claude/CLAUDE.md to apply across all projects

Option 3: Git commit-msg Hook

Use a native git hook to strip the trailer automatically — works regardless of who or what creates the commit.

Create the hook

cat > .git/hooks/commit-msg << 'EOF'
#!/bin/sh
# Remove Co-Authored-By lines from commit messages
sed -i.bak '/^Co-Authored-By:/d' "$1"
rm -f "$1.bak"
EOF
chmod +x .git/hooks/commit-msg

This runs after every commit message is finalized and strips any Co-Authored-By: line.

Make it portable with a global git hook

To apply across all repos:

# Set a global hooks directory
mkdir -p ~/.git-hooks
git config --global core.hooksPath ~/.git-hooks

# Create the global commit-msg hook
cat > ~/.git-hooks/commit-msg << 'EOF'
#!/bin/sh
sed -i.bak '/^Co-Authored-By:/d' "$1"
rm -f "$1.bak"
EOF
chmod +x ~/.git-hooks/commit-msg

Option 4: Claude Code Hook

Use a Claude Code PostToolUse hook to amend the most recent commit and strip the trailer after Claude runs a Bash command containing git commit.

Add to .claude/settings.json or ~/.claude/settings.json:

{
  "hooks": {
    "PostToolUse": [
      {
        "matcher": "Bash",
        "hooks": [
          {
            "type": "command",
            "command": "if echo \"$CLAUDE_TOOL_INPUT\" | grep -q 'git commit'; then git log -1 --format='%B' | sed '/^Co-Authored-By:/d' | git commit --amend -F -; fi"
          }
        ]
      }
    ]
  }
}

This watches for git commit commands and immediately amends the commit to remove the trailer.

Removing from Existing Commits

Last commit only

git log -1 --format='%B' | sed '/^Co-Authored-By:/d' | git commit --amend -F -

Multiple recent commits

Use interactive rebase to reword commits:

# Rebase last N commits (e.g., last 5)
git rebase -i HEAD~5

Mark commits as reword, then remove the Co-Authored-By line from each message.

Bulk removal with filter-branch

Warning: This rewrites history. Only use on branches that haven't been shared.

git filter-branch --msg-filter 'sed "/^Co-Authored-By:/d"' HEAD~10..HEAD

Which Option Should You Use?

Recommendation: Use the includeCoAuthoredBy setting — it's the official, built-in way. Add a git commit-msg hook as a belt-and-suspenders safety net if desired.