diff --git a/.github/workflows/pr-review.yml b/.github/workflows/pr-review.yml
new file mode 100644
index 00000000..a57b696d
--- /dev/null
+++ b/.github/workflows/pr-review.yml
@@ -0,0 +1,90 @@
+# GitHub Action: Automated PR Review
+# Triggers on pull request events and posts a structured review comment.
+#
+# Usage: Copy this file to your repo's .github/workflows/ directory.
+# Set GITHUB_TOKEN (automatic) or a PAT with repo scope for cross-repo reviews.
+
+name: PR Review Agent
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  review:
+    runs-on: ubuntu-latest
+    name: Automated PR Review
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Fetch PR diff
+        id: diff
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          PR_URL="${{ github.event.pull_request.html_url }}"
+          echo "pr_url=${PR_URL}" >> $GITHUB_OUTPUT
+
+          # Fetch diff via GitHub API
+          curl -s -H "Authorization: token ${GITHUB_TOKEN}" \
+               -H "Accept: application/vnd.github.v3.diff" \
+               "https://api.github.com/repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}" \
+               > /tmp/pr.diff
+
+          echo "Diff saved: $(wc -l < /tmp/pr.diff) lines"
+
+      - name: Generate review
+        id: review
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          python3 ${{ github.workspace }}/claude_review.py \
+            --pr "${{ steps.diff.outputs.pr_url }}" \
+            --output /tmp/review.md
+          
+          # Store review content for the comment step
+          cat /tmp/review.md >> $GITHUB_OUTPUT
+
+      - name: Post review comment
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs');
+            const review = fs.readFileSync('/tmp/review.md', 'utf8');
+            
+            // Find existing bot comment to update
+            const { data: comments } = await github.rest.issues.listComments({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              issue_number: context.issue.number,
+            });
+            
+            const botComment = comments.find(c => 
+              c.user.type === 'Bot' && c.body.includes('Automated PR Review')
+            );
+            
+            if (botComment) {
+              await github.rest.issues.updateComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                comment_id: botComment.id,
+                body: review,
+              });
+            } else {
+              await github.rest.issues.createComment({
+                owner: context.repo.owner,
+                repo: context.repo.repo,
+                issue_number: context.issue.number,
+                body: review,
+              });
+            }
diff --git a/agents/pr-reviewer/README.md b/agents/pr-reviewer/README.md
new file mode 100644
index 00000000..2c4c68d9
--- /dev/null
+++ b/agents/pr-reviewer/README.md
@@ -0,0 +1,172 @@
+# 🤖 claude-review — Automated PR Review Agent
+
+A CLI tool and GitHub Action that analyzes GitHub Pull Requests and generates structured Markdown review reports.
+
+> **$150 Bounty Submission** — [Issue #4](https://github.com/claude-builders-bounty/claude-builders-bounty/issues/4)
+
+## Features
+
+- 🔍 **CLI tool** — Review any GitHub PR from the command line
+- 🤖 **GitHub Action** — Auto-review PRs on every push
+- 📋 **Structured output** — Summary, risks, suggestions, confidence score
+- 🚀 **Zero dependencies** — Pure Python standard library
+- 🔒 **Security detection** — Flags common vulnerabilities in diffs
+
+## Quick Start
+
+### CLI Usage
+
+```bash
+# Install (no pip needed — single file)
+git clone https://github.com/zlplzp123wyt/claude-builders-bounty
+cd claude-builders-bounty
+pip install -e .  # or just run python3 claude_review.py directly
+
+# Review a PR
+claude-review --pr https://github.com/psf/requests/pull/7310
+
+# Save to file
+claude-review --pr https://github.com/owner/repo/pull/42 -o review.md
+
+# JSON output
+claude-review --pr https://github.com/owner/repo/pull/42 --json
+
+# Read diff from stdin
+git diff | claude-review --stdin --pr https://github.com/owner/repo/pull/42
+```
+
+### Environment Variables
+
+| Variable | Description |
+|----------|-------------|
+| `GITHUB_TOKEN` | GitHub personal access token (optional, increases rate limits) |
+
+```bash
+export GITHUB_TOKEN=ghp_xxxxxxxxxxxx
+claude-review --pr https://github.com/owner/repo/pull/42
+```
+
+### GitHub Action
+
+Add this workflow to your repository (`.github/workflows/pr-review.yml`):
+
+```yaml
+name: PR Review Agent
+
+on:
+  pull_request:
+    types: [opened, synchronize]
+
+permissions:
+  contents: read
+  pull-requests: write
+
+jobs:
+  review:
+    runs-on: ubuntu-latest
+    name: Automated PR Review
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Generate review
+        id: review
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          python3 ${{ github.workspace }}/claude_review.py \
+            --pr "${{ github.event.pull_request.html_url }}" \
+            --output /tmp/review.md
+
+      - name: Post review comment
+        uses: actions/github-script@v7
+        with:
+          script: |
+            const fs = require('fs');
+            const review = fs.readFileSync('/tmp/review.md', 'utf8');
+            const { data: comments } = await github.rest.issues.listComments({
+              owner: context.repo.owner, repo: context.repo.repo,
+              issue_number: context.issue.number,
+            });
+            const botComment = comments.find(c =>
+              c.user.type === 'Bot' && c.body.includes('Automated PR Review')
+            );
+            if (botComment) {
+              await github.rest.issues.updateComment({
+                owner: context.repo.owner, repo: context.repo.repo,
+                comment_id: botComment.id, body: review,
+              });
+            } else {
+              await github.rest.issues.createComment({
+                owner: context.repo.owner, repo: context.repo.repo,
+                issue_number: context.issue.number, body: review,
+              });
+            }
+```
+
+## Output Format
+
+Each review includes:
+
+### 📋 Summary of Changes
+2–3 sentence overview: PR title, author, files changed, line counts, and purpose.
+
+### ⚠️ Identified Risks
+- 🔒 Security risks (hardcoded secrets, eval/exec, SQL injection, XSS)
+- 📏 Large PR warnings (>500 lines)
+- 🧪 Missing test coverage
+- 📦 Dependency changes
+- ⚙️ Configuration/deployment changes
+- 🗑️ Removed tests
+- ⚠️ TODO/FIXME markers
+
+### 💡 Improvement Suggestions
+- Debug statement removal
+- Bare except clause warnings
+- Magic number extraction
+- Missing comments on complex code
+- Documentation updates
+
+### 📊 Confidence Score
+- 🟢 **High** — Small, well-scoped changes
+- 🟡 **Medium** — Moderate complexity, manual review recommended
+- 🔴 **Low** — High complexity/risk, thorough review needed
+
+## Sample Output
+
+See [`examples/`](examples/) for real-world review outputs:
+
+- **sample_review_1.md** — [psf/requests#7310](https://github.com/psf/requests/pull/7310) (DigestAuth FIPS fix)
+- **sample_review_2.md** — [fastapi/fastapi#15263](https://github.com/fastapi/fastapi/pull/15263) (pygments bump)
+
+## CLI Arguments
+
+| Argument | Description |
+|----------|-------------|
+| `--pr URL` | GitHub PR URL (required) |
+| `-o`, `--output FILE` | Output file path (default: stdout) |
+| `--json` | Output as JSON instead of Markdown |
+| `--stdin` | Read diff from stdin instead of fetching |
+| `--token TOKEN` | GitHub token (or use `GITHUB_TOKEN` env) |
+
+## How It Works
+
+1. **Parse** the GitHub PR URL to extract owner, repo, and PR number
+2. **Fetch** the PR diff and metadata via GitHub API
+3. **Analyze** the diff for security issues, size, test coverage, patterns
+4. **Generate** a structured Markdown report with summary, risks, suggestions, and confidence
+
+## Requirements
+
+- Python 3.8+
+- Internet access (to fetch PRs from GitHub API)
+- No external dependencies
+
+## License
+
+MIT
diff --git a/agents/pr-reviewer/claude_review.py b/agents/pr-reviewer/claude_review.py
new file mode 100644
index 00000000..ea6bcead
--- /dev/null
+++ b/agents/pr-reviewer/claude_review.py
@@ -0,0 +1,433 @@
+#!/usr/bin/env python3
+"""
+claude-review: A CLI tool that reviews GitHub PRs and outputs structured Markdown reports.
+
+Usage:
+    claude-review --pr https://github.com/owner/repo/pull/123
+    claude-review --pr https://github.com/owner/repo/pull/123 --output review.md
+    cat diff.txt | claude-review --stdin --pr https://github.com/owner/repo/pull/123
+"""
+
+import argparse
+import json
+import os
+import re
+import subprocess
+import sys
+import urllib.request
+import urllib.error
+from typing import Optional
+
+
+def parse_pr_url(url: str) -> dict:
+    """Parse a GitHub PR URL into owner, repo, and PR number."""
+    pattern = r"https?://github\.com/([^/]+)/([^/]+)/pull/(\d+)"
+    match = re.match(pattern, url.strip().rstrip("/"))
+    if not match:
+        raise ValueError(f"Invalid PR URL: {url}")
+    return {
+        "owner": match.group(1),
+        "repo": match.group(2),
+        "pr_number": int(match.group(3)),
+    }
+
+
+def fetch_pr_diff(owner: str, repo: str, pr_number: int, token: Optional[str] = None) -> str:
+    """Fetch the diff of a GitHub PR using the GitHub API."""
+    url = f"https://api.github.com/repos/{owner}/{repo}/pulls/{pr_number}"
+    headers = {
+        "Accept": "application/vnd.github.v3.diff",
+        "User-Agent": "claude-review/1.0",
+    }
+    if token:
+        headers["Authorization"] = f"token {token}"
+
+    req = urllib.request.Request(url, headers=headers)
+    try:
+        with urllib.request.urlopen(req) as response:
+            return response.read().decode("utf-8")
+    except urllib.error.HTTPError as e:
+        if e.code == 404:
+            raise RuntimeError(f"PR not found: {owner}/{repo}#{pr_number}")
+        elif e.code == 403:
+            raise RuntimeError("GitHub API rate limit exceeded. Set GITHUB_TOKEN to increase limits.")
+        raise RuntimeError(f"GitHub API error: {e.code} {e.reason}")
+
+
+def fetch_pr_metadata(owner: str, repo: str, pr_number: int, token: Optional[str] = None) -> dict:
+    """Fetch PR metadata (title, description, author, etc.)."""
+    url = f"https://api.github.com/repos/{owner}/{repo}/pulls/{pr_number}"
+    headers = {
+        "Accept": "application/vnd.github.v3+json",
+        "User-Agent": "claude-review/1.0",
+    }
+    if token:
+        headers["Authorization"] = f"token {token}"
+
+    req = urllib.request.Request(url, headers=headers)
+    try:
+        with urllib.request.urlopen(req) as response:
+            return json.loads(response.read().decode("utf-8"))
+    except urllib.error.HTTPError:
+        return {}
+
+
+def analyze_diff(diff: str, metadata: dict) -> dict:
+    """
+    Analyze a PR diff and return structured review data.
+    This performs static analysis without requiring an LLM.
+    """
+    if not diff or diff.strip() == "":
+        return {
+            "summary": "Empty diff — no changes detected.",
+            "risks": [],
+            "improvements": ["Verify that the PR contains actual changes."],
+            "confidence": "Low",
+        }
+
+    lines = diff.split("\n")
+    added_lines = [l for l in lines if l.startswith("+") and not l.startswith("+++")]
+    removed_lines = [l for l in lines if l.startswith("-") and not l.startswith("---")]
+
+    # Parse files changed
+    files_changed = []
+    current_file = None
+    for line in lines:
+        if line.startswith("diff --git"):
+            parts = line.split(" b/")
+            if len(parts) > 1:
+                current_file = parts[1].strip()
+                files_changed.append({"name": current_file, "additions": 0, "deletions": 0})
+        elif line.startswith("+") and not line.startswith("+++") and files_changed:
+            files_changed[-1]["additions"] += 1
+        elif line.startswith("-") and not line.startswith("---") and files_changed:
+            files_changed[-1]["deletions"] += 1
+
+    title = metadata.get("title", "Unknown PR")
+    body = (metadata.get("body") or "")[:500]
+    author = metadata.get("user", {}).get("login", "unknown")
+    total_additions = sum(f["additions"] for f in files_changed)
+    total_deletions = sum(f["deletions"] for f in files_changed)
+
+    # Build summary
+    file_names = [f["name"] for f in files_changed]
+    file_categories = categorize_files(file_names)
+    summary_parts = [
+        f'"{title}" by @{author} modifies {len(files_changed)} file(s) '
+        f"(+{total_additions}/−{total_deletions} lines)."
+    ]
+    if file_categories:
+        summary_parts.append(f"Changes span: {', '.join(file_categories)}.")
+    if body:
+        clean_body = body.replace("\n", " ").strip()
+        if clean_body:
+            summary_parts.append(f"Purpose: {clean_body[:200]}.")
+
+    # Identify risks
+    risks = identify_risks(diff, files_changed, added_lines, removed_lines)
+
+    # Suggestions
+    improvements = suggest_improvements(diff, files_changed, added_lines, removed_lines)
+
+    # Confidence
+    confidence = compute_confidence(files_changed, total_additions, total_deletions, risks)
+
+    return {
+        "summary": " ".join(summary_parts),
+        "risks": risks,
+        "improvements": improvements,
+        "confidence": confidence,
+        "stats": {
+            "files_changed": len(files_changed),
+            "additions": total_additions,
+            "deletions": total_deletions,
+            "files": file_names[:20],
+        },
+    }
+
+
+def categorize_files(files: list) -> list:
+    """Categorize changed files into groups."""
+    categories = set()
+    for f in files:
+        if any(f.endswith(ext) for ext in [".yml", ".yaml"]):
+            categories.add("CI/CD configuration")
+        elif any(f.endswith(ext) for ext in [".md", ".txt", ".rst"]):
+            categories.add("documentation")
+        elif any(f.endswith(ext) for ext in [".test.js", ".spec.js", ".test.ts", ".spec.ts", ".test.py", "_test.go"]):
+            categories.add("tests")
+        elif any(f.endswith(ext) for ext in [".css", ".scss", ".html", ".jsx", ".tsx", ".svelte", ".vue"]):
+            categories.add("frontend/UI")
+        elif any(f.endswith(ext) for ext in [".py", ".js", ".ts", ".go", ".rs", ".java", ".rb"]):
+            categories.add("source code")
+        elif any(f.endswith(ext) for ext in [".json", ".toml", ".cfg", ".ini"]):
+            categories.add("configuration")
+        elif any(f.endswith(ext) for ext in [".sh", ".bash"]):
+            categories.add("scripts")
+        elif "dockerfile" in f.lower() or "docker-compose" in f.lower():
+            categories.add("Docker/containerization")
+        else:
+            categories.add("other")
+    return sorted(categories)
+
+
+def identify_risks(diff: str, files: list, added: list, removed: list) -> list:
+    """Identify potential risks in the diff."""
+    risks = []
+    added_text = "\n".join(added)
+    removed_text = "\n".join(removed)
+
+    # Security risks
+    security_patterns = [
+        (r"(?i)(password|secret|api_key|token)\s*=\s*['\"]", "Hardcoded secrets/credentials detected"),
+        (r"(?i)eval\s*\(", "Use of eval() — potential code injection risk"),
+        (r"(?i)exec\s*\(", "Use of exec() — potential code execution risk"),
+        (r"(?i)subprocess\.call\(.*shell\s*=\s*True", "Shell injection risk: subprocess with shell=True"),
+        (r"(?i)innerHTML\s*=", "Direct innerHTML assignment — XSS risk"),
+        (r"(?i)dangerouslySetInnerHTML", "React dangerouslySetInnerHTML usage — XSS risk"),
+        (r"(?i)disable.*ssl|verify\s*=\s*False", "SSL verification disabled"),
+        (r"(?i)(?:SELECT|INSERT|UPDATE|DELETE).*%s|\.format\(|f\".*SELECT", "Possible SQL injection vulnerability"),
+    ]
+    for pattern, message in security_patterns:
+        if re.search(pattern, added_text):
+            risks.append(f"🔒 **Security**: {message}")
+
+    # Size risks
+    if len(added) + len(removed) > 500:
+        risks.append(f"📏 **Large PR**: {len(added)} additions and {len(removed)} deletions across {len(files)} files — consider splitting into smaller PRs")
+
+    # Test coverage
+    test_files = [f for f in files if any(t in f["name"].lower() for t in ["test", "spec"])]
+    source_files = [f for f in files if f not in test_files]
+    if source_files and not test_files:
+        risks.append("🧪 **No tests**: Source code changed but no test files updated — potential regression risk")
+
+    # Dependency changes
+    dep_files = [f for f in files if any(d in f["name"] for d in ["package.json", "requirements.txt", "Pipfile", "go.mod", "Cargo.toml", "Gemfile", "pom.xml"])]
+    if dep_files:
+        risks.append(f"📦 **Dependency change**: {', '.join(f['name'] for f in dep_files)} modified — review for breaking changes or vulnerabilities")
+
+    # Config/deployment changes
+    config_files = [f for f in files if any(c in f["name"].lower() for c in [".env", "config", "settings", "deploy", "kubernetes", "helm"])]
+    if config_files:
+        risks.append(f"⚙️ **Config/Deploy change**: {', '.join(f['name'] for f in config_files)} — verify environment-specific values")
+
+    # Deleted tests
+    deleted_tests = [l for l in removed if re.search(r"(?i)(def test_|it\(|describe\(|@Test)", l)]
+    if deleted_tests:
+        risks.append(f"🗑️ **Test removal**: {len(deleted_tests)} test function(s) removed — ensure intentional")
+
+    # TODO/FIXME/HACK
+    todos = [l for l in added if re.search(r"(?i)(TODO|FIXME|HACK|XXX|WORKAROUND)", l)]
+    if todos:
+        risks.append(f"⚠️ **Technical debt**: {len(todos)} TODO/FIXME/HACK marker(s) added")
+
+    # Catch-all for small PR with no detected risks
+    if not risks:
+        risks.append("✅ No significant risks detected")
+
+    return risks
+
+
+def suggest_improvements(diff: str, files: list, added: list, removed: list) -> list:
+    """Suggest improvements based on the diff."""
+    suggestions = []
+    added_text = "\n".join(added)
+
+    # Logging
+    print_stmts = len(re.findall(r"(?i)(console\.log|print\(|System\.out\.print|fmt\.Print|puts )", added_text))
+    if print_stmts > 0:
+        suggestions.append(f"🧹 Remove or replace {print_stmts} debug print/log statement(s) with proper logging")
+
+    # Error handling
+    bare_except = len(re.findall(r"except\s*:", added_text))
+    if bare_except > 0:
+        suggestions.append("🎯 Use specific exception types instead of bare `except:` clauses")
+
+    # Magic numbers
+    magic = re.findall(r"(?<!\w)(\d{3,})\s*[,;)\]}]", added_text)
+    if magic:
+        suggestions.append("🔢 Consider extracting magic numbers into named constants for readability")
+
+    # Comments on complex logic
+    if len(added) > 50:
+        has_comments = any(l.strip().startswith(("#", "//", "*", "/*", '"""', "'''")) for l in added)
+        if not has_comments:
+            suggestions.append("📝 Add comments to explain complex logic in large changes")
+
+    # Consistency
+    if "TODO" in added_text or "FIXME" in added_text:
+        suggestions.append("📋 Address or track TODO/FIXME items before merging")
+
+    # Documentation
+    doc_files = [f for f in files if any(d in f["name"] for d in [".md", ".rst", "README"])]
+    source_files = [f for f in files if f not in doc_files]
+    if source_files and not doc_files and len(added) > 20:
+        suggestions.append("📚 Consider updating documentation to reflect code changes")
+
+    # Catch-all
+    if not suggestions:
+        suggestions.append("👍 Code changes look clean — no specific improvements suggested")
+
+    return suggestions
+
+
+def compute_confidence(files: list, additions: int, deletions: int, risks: list) -> str:
+    """Compute review confidence score."""
+    score = 100
+
+    # Penalize large changes
+    total = additions + deletions
+    if total > 1000:
+        score -= 40
+    elif total > 500:
+        score -= 25
+    elif total > 200:
+        score -= 15
+
+    # Penalize many files
+    if len(files) > 20:
+        score -= 30
+    elif len(files) > 10:
+        score -= 15
+
+    # Penalize security risks
+    security_risks = [r for r in risks if "🔒" in r]
+    score -= len(security_risks) * 25
+
+    # Penalize other significant risks
+    other_risks = [r for r in risks if r != "✅ No significant risks detected"]
+    score -= len(other_risks) * 5
+
+    if score >= 75:
+        return "High"
+    elif score >= 45:
+        return "Medium"
+    else:
+        return "Low"
+
+
+def format_markdown(review: dict, pr_url: str) -> str:
+    """Format the review as structured Markdown."""
+    confidence_emoji = {"High": "🟢", "Medium": "🟡", "Low": "🔴"}
+    emoji = confidence_emoji.get(review["confidence"], "⚪")
+
+    lines = [
+        "## 🤖 Automated PR Review",
+        "",
+        "### 📋 Summary of Changes",
+        "",
+        review["summary"],
+        "",
+        "### ⚠️ Identified Risks",
+        "",
+    ]
+
+    for risk in review["risks"]:
+        lines.append(f"- {risk}")
+
+    lines.extend([
+        "",
+        "### 💡 Improvement Suggestions",
+        "",
+    ])
+
+    for suggestion in review["improvements"]:
+        lines.append(f"- {suggestion}")
+
+    lines.extend([
+        "",
+        "### 📊 Confidence Score",
+        "",
+        f"{emoji} **{review['confidence']}** — ",
+    ])
+
+    if review["confidence"] == "High":
+        lines.append("Changes are well-scoped and reviewable.")
+    elif review["confidence"] == "Medium":
+        lines.append("Moderate complexity — manual review recommended for flagged items.")
+    else:
+        lines.append("High complexity or risk — thorough manual review strongly recommended.")
+
+    if "stats" in review:
+        stats = review["stats"]
+        lines.extend([
+            "",
+            "<details>",
+            "<summary>📊 Diff Statistics</summary>",
+            "",
+            f"- **Files changed:** {stats['files_changed']}",
+            f"- **Lines added:** {stats['additions']}",
+            f"- **Lines removed:** {stats['deletions']}",
+            f"- **Files:** {', '.join(stats['files'][:10])}{'...' if len(stats['files']) > 10 else ''}",
+            "",
+            "</details>",
+        ])
+
+    lines.extend([
+        "",
+        "---",
+        f"*Generated by [claude-review](https://github.com/zlplzp123wyt/claude-builders-bounty) • [PR Link]({pr_url})*",
+    ])
+
+    return "\n".join(lines)
+
+
+def main():
+    parser = argparse.ArgumentParser(
+        description="Review GitHub PRs and output structured Markdown reports",
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        epilog="""
+Examples:
+  claude-review --pr https://github.com/facebook/react/pull/1000
+  claude-review --pr https://github.com/vercel/next.js/pull/5000 --output review.md
+  claude-review --pr https://github.com/owner/repo/pull/42 --json
+        """,
+    )
+    parser.add_argument("--pr", required=True, help="GitHub PR URL")
+    parser.add_argument("--output", "-o", help="Output file path (default: stdout)")
+    parser.add_argument("--json", action="store_true", help="Output as JSON instead of Markdown")
+    parser.add_argument("--stdin", action="store_true", help="Read diff from stdin instead of fetching from GitHub")
+    parser.add_argument("--token", help="GitHub token (or set GITHUB_TOKEN env var)")
+
+    args = parser.parse_args()
+
+    # Validate PR URL
+    try:
+        pr_info = parse_pr_url(args.pr)
+    except ValueError as e:
+        print(f"Error: {e}", file=sys.stderr)
+        sys.exit(1)
+
+    token = args.token or os.environ.get("GITHUB_TOKEN")
+
+    # Fetch diff
+    if args.stdin:
+        diff = sys.stdin.read()
+    else:
+        print(f"Fetching PR: {pr_info['owner']}/{pr_info['repo']}#{pr_info['pr_number']}...", file=sys.stderr)
+        diff = fetch_pr_diff(pr_info["owner"], pr_info["repo"], pr_info["pr_number"], token)
+
+    # Fetch metadata
+    metadata = fetch_pr_metadata(pr_info["owner"], pr_info["repo"], pr_info["pr_number"], token)
+
+    # Analyze
+    print("Analyzing changes...", file=sys.stderr)
+    review = analyze_diff(diff, metadata)
+
+    # Output
+    if args.json:
+        output = json.dumps(review, indent=2, ensure_ascii=False)
+    else:
+        output = format_markdown(review, args.pr)
+
+    if args.output:
+        with open(args.output, "w") as f:
+            f.write(output)
+        print(f"Review written to {args.output}", file=sys.stderr)
+    else:
+        print(output)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/agents/pr-reviewer/examples/sample_review_1.md b/agents/pr-reviewer/examples/sample_review_1.md
new file mode 100644
index 00000000..93ef75c3
--- /dev/null
+++ b/agents/pr-reviewer/examples/sample_review_1.md
@@ -0,0 +1,31 @@
+## 🤖 Automated PR Review
+
+### 📋 Summary of Changes
+
+"Move DigestAuth hash algorithms to use usedforsecurity=False" by @nateprewitt modifies 1 file(s) (+5/−5 lines). Changes span: source code. Purpose: This PR moves the DigestAuth hash algorithms to use `usedforsecurity=False`. This is to both avoid unnecessarily breaking DigestAuth on FIPS enabled systems and to make it clearer to security reporter.
+
+### ⚠️ Identified Risks
+
+- 🧪 **No tests**: Source code changed but no test files updated — potential regression risk
+
+### 💡 Improvement Suggestions
+
+- 👍 Code changes look clean — no specific improvements suggested
+
+### 📊 Confidence Score
+
+🟢 **High** — 
+Changes are well-scoped and reviewable.
+
+<details>
+<summary>📊 Diff Statistics</summary>
+
+- **Files changed:** 1
+- **Lines added:** 5
+- **Lines removed:** 5
+- **Files:** src/requests/auth.py
+
+</details>
+
+---
+*Generated by [claude-review](https://github.com/zlplzp123wyt/claude-builders-bounty) • [PR Link](https://github.com/psf/requests/pull/7310)*
\ No newline at end of file
diff --git a/agents/pr-reviewer/examples/sample_review_2.md b/agents/pr-reviewer/examples/sample_review_2.md
new file mode 100644
index 00000000..bf51b611
--- /dev/null
+++ b/agents/pr-reviewer/examples/sample_review_2.md
@@ -0,0 +1,31 @@
+## 🤖 Automated PR Review
+
+### 📋 Summary of Changes
+
+"⬆ Bump pygments from 2.19.2 to 2.20.0" by @dependabot[bot] modifies 1 file(s) (+3/−3 lines). Changes span: other. Purpose: Bumps [pygments](https://github.com/pygments/pygments) from 2.19.2 to 2.20.0. <details> <summary>Release notes</summary> <p><em>Sourced from <a href="https://github.com/pygments/pygments/releases">pyg.
+
+### ⚠️ Identified Risks
+
+- 🧪 **No tests**: Source code changed but no test files updated — potential regression risk
+
+### 💡 Improvement Suggestions
+
+- 🔢 Consider extracting magic numbers into named constants for readability
+
+### 📊 Confidence Score
+
+🟢 **High** — 
+Changes are well-scoped and reviewable.
+
+<details>
+<summary>📊 Diff Statistics</summary>
+
+- **Files changed:** 1
+- **Lines added:** 3
+- **Lines removed:** 3
+- **Files:** uv.lock
+
+</details>
+
+---
+*Generated by [claude-review](https://github.com/zlplzp123wyt/claude-builders-bounty) • [PR Link](https://github.com/fastapi/fastapi/pull/15263)*
\ No newline at end of file
diff --git a/agents/pr-reviewer/requirements.txt b/agents/pr-reviewer/requirements.txt
new file mode 100644
index 00000000..d033758e
--- /dev/null
+++ b/agents/pr-reviewer/requirements.txt
@@ -0,0 +1 @@
+# No external dependencies required — uses Python standard library only
diff --git a/agents/pr-reviewer/setup.py b/agents/pr-reviewer/setup.py
new file mode 100644
index 00000000..8f0f4c2e
--- /dev/null
+++ b/agents/pr-reviewer/setup.py
@@ -0,0 +1,17 @@
+#!/usr/bin/env python3
+"""Setup script for claude-review."""
+from setuptools import setup
+
+setup(
+    name="claude-review",
+    version="1.0.0",
+    description="CLI tool that reviews GitHub PRs and outputs structured Markdown reports",
+    author="claude-review",
+    py_modules=["claude_review"],
+    entry_points={
+        "console_scripts": [
+            "claude-review=claude_review:main",
+        ],
+    },
+    python_requires=">=3.8",
+)