diff --git a/.github/scripts/check-ai-co-authors.sh b/.github/scripts/check-ai-co-authors.sh
new file mode 100755
index 000000000..842b1f2d8
--- /dev/null
+++ b/.github/scripts/check-ai-co-authors.sh
@@ -0,0 +1,103 @@
+#!/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 ${base_sha}"
+    echo ""
+    echo "and remove the Co-authored-by lines, then force-push your branch."
+    echo ""
+    echo "If you believe this is a false positive, please open an issue."
+    exit 1
+fi
+
+echo "No AI agent Co-authored-by trailers found."
diff --git a/.github/workflows/check-ai-co-authors.yml b/.github/workflows/check-ai-co-authors.yml
new file mode 100644
index 000000000..2ad9ac972
--- /dev/null
+++ b/.github/workflows/check-ai-co-authors.yml
@@ -0,0 +1,19 @@
+name: Check AI Co-Authors
+
+on:
+  pull_request:
+    branches: ['*']
+
+jobs:
+  check-ai-co-authors:
+    name: Check for AI agent co-author trailers
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Check commits for AI co-author trailers
+        run: bash .github/scripts/check-ai-co-authors.sh "${{ github.event.pull_request.base.sha }}" "${{ github.event.pull_request.head.sha }}"