#!/usr/bin/env bash

# Checks pull request commits for AI agent Co-authored-by trailers.

# Exits non-zero when any are found and prints fix instructions.

set -euo pipefail

base_sha="${1:?usage: check-ai-co-authors.sh <base_sha> <head_sha>}"

head_sha="${2:?usage: check-ai-co-authors.sh <base_sha> <head_sha>}"

# Known AI coding-agent trailer patterns (case-insensitive).

# Each entry is an extended-regex fragment matched against Co-authored-by lines.

AGENT_PATTERNS=(

# Anthropic — Claude Code / Amp

'noreply@anthropic\.com'

# Cursor

'cursoragent@cursor\.com'

# GitHub Copilot

'copilot-swe-agent\[bot\]'

'copilot@github\.com'

# OpenAI Codex

'noreply@openai\.com'

'codex@openai\.com'

# Aider

'aider@aider\.chat'

# Google — Gemini / Jules

'gemini@google\.com'

'jules@google\.com'

# Windsurf / Codeium

'@codeium\.com'

# Devin

'devin-ai-integration\[bot\]'

'devin@cognition\.ai'

'devin@cognition-labs\.com'

# Amazon Q Developer

'amazon-q-developer'

'@amazon\.com.*[Qq].[Dd]eveloper'

# Cline

'cline-bot'

'cline@cline\.ai'

# Continue

'continue-agent'

'continue@continue\.dev'

# Sourcegraph

'noreply@sourcegraph\.com'

# Generic catch-alls for common agent name patterns

'Co-authored-by:.*\b[Cc]laude\b'

'Co-authored-by:.*\b[Cc]opilot\b'

'Co-authored-by:.*\b[Cc]ursor\b'

'Co-authored-by:.*\b[Cc]odex\b'

'Co-authored-by:.*\b[Gg]emini\b'

'Co-authored-by:.*\b[Aa]ider\b'

'Co-authored-by:.*\b[Dd]evin\b'

'Co-authored-by:.*\b[Ww]indsurf\b'

'Co-authored-by:.*\b[Cc]line\b'

'Co-authored-by:.*\b[Aa]mazon Q\b'

'Co-authored-by:.*\b[Jj]ules\b'

'Co-authored-by:.*\bOpenCode\b'

)

# Build a single alternation regex from all patterns.

regex=""

for pattern in "${AGENT_PATTERNS[@]}"; do

if [[ -n "$regex" ]]; then

regex="${regex}|${pattern}"

else

regex="$pattern"

fi

done

# Collect Co-authored-by lines from every commit in the PR range.

violations=""

while IFS= read -r sha; do

message="$(git log -1 --format='%B' "$sha")"

matched_lines="$(echo "$message" | grep -iE "^Co-authored-by:" || true)"

if [[ -z "$matched_lines" ]]; then

continue

fi

while IFS= read -r line; do

if echo "$line" | grep -iqE "$regex"; then

short="$(git log -1 --format='%h' "$sha")"

violations="${violations} ${short}: ${line}"$'\n'

fi

done <<< "$matched_lines"

done < <(git rev-list "${base_sha}..${head_sha}")

if [[ -n "$violations" ]]; then

echo "::error::AI agent Co-authored-by trailers detected in PR commits."

echo ""

echo "The following commits contain Co-authored-by trailers from AI coding agents:"

echo ""

echo "$violations"

echo "These trailers should be removed before merging."

echo ""

echo "To fix, rewrite the commit messages with:"

echo " git rebase -i ${base_sha}"

echo ""

echo "and remove the Co-authored-by lines, then force-push your branch."

echo ""

echo "If you believe this is a false positive, please open an issue."

exit 1

fi

echo "No AI agent Co-authored-by trailers found."