AI Code Reviewer

AI-powered code review for GitHub pull requests.

One-line setup. Zero config. Works with any LLM.

Used by [X] developers · [Y] reviews completed · $0.002/review with Groq

Quick Start · /fix · Playground · Pre-Commit · Providers · /review · GitLab · VS Code · Self-Hosted

Why teams choose AI Code Reviewer

Review summary

Inline comments with suggested fixes

Quick Start

1. Add the workflow (30 seconds)

Create .github/workflows/ai-review.yml:

name: AI Code Review

on:
  pull_request:
    types: [opened, synchronize, reopened]

permissions:
  contents: read
  pull-requests: write

jobs:
  review:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: mara-werils/ai-code-reviewer@v1
        env:
          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}

2. Add your API key

Go to Settings > Secrets > Actions and add your API key.

3. Open a PR

That's it. AI review lands in 30 seconds.

Want the cheapest option? Use Groq with Llama 3.3 — it's $0.002/review with a free API key.

Auto-Fix with /fix

Type /fix in any PR comment after a review — AI reads the review comments, generates fixes, and commits them directly to your branch.

You:  /fix
AI:   👀 Analyzing 3 issues from the review...
AI:   ## AI Code Fix
      Applied 3 fixes across 2 files.

      ### src/db.py
      - Fixed SQL injection by using parameterized query
      - Added input validation for user_id
        Commit: abc1234

      ### src/api.py
      - Added null check before accessing response.data
        Commit: def5678

How it works:

1. AI collects all [CRITICAL] and [WARNING] comments from the last review
2. For each file: reads the current content, generates fixed version via LLM
3. Commits each fix directly to the PR branch
4. Posts a summary of what was fixed and what was skipped

Requires contents: write permission. Add /fix support with the on-demand workflow.

Try It Online (No Install)

Paste any public GitHub PR URL and get an AI review instantly:

# Self-host the playground
git clone https://github.com/mara-werils/ai-code-reviewer.git
cd ai-code-reviewer
pip install . uvicorn starlette
export GROQ_API_KEY=gsk_...
export GITHUB_TOKEN=ghp_...
uvicorn playground.app:app --port 8000

# Or with Docker
docker build -t pr-reviewer-playground playground/
docker run -p 8000:8000 -e GROQ_API_KEY=gsk_... -e GITHUB_TOKEN=ghp_... pr-reviewer-playground

Open http://localhost:8000 — paste a PR URL, get a review. Share the link with your team.

Pre-Commit Hook

Review code before every commit. Catches issues before they reach the PR.

# .pre-commit-config.yaml
repos:
  - repo: https://github.com/mara-werils/ai-code-reviewer
    rev: v0.4.0
    hooks:
      - id: ai-code-review

# Install and run
pip install pre-commit
pre-commit install

# Now every git commit runs AI review on staged changes
git commit -m "feat: add new endpoint"
# AI Code Review: scanning 3 files (42 lines changed)...
# CRITICAL src/api.py:15
#   SQL injection vulnerability: user input passed directly to query
# Commit blocked: 1 issue(s) at or above threshold.

Configuration

Set SEVERITY_THRESHOLD=warning to also block on warnings. Use --no-verify to skip in a hurry.

On-Demand Review

Type /review in any PR comment to trigger a review on demand.

# Add to your workflow to enable /review command
on:
  pull_request:
    types: [opened, synchronize, reopened]
  issue_comment:
    types: [created]

jobs:
  auto-review:
    if: github.event_name == 'pull_request'
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: mara-werils/ai-code-reviewer@v1
        env:
          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}

  on-demand:
    if: >
      github.event_name == 'issue_comment' &&
      github.event.issue.pull_request &&
      startsWith(github.event.comment.body, '/review')
    runs-on: ubuntu-latest
    steps:
      - name: React to comment
        uses: actions/github-script@v7
        with:
          script: |
            await github.rest.reactions.createForIssueComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              comment_id: context.payload.comment.id,
              content: 'eyes'
            });
      - name: Get PR ref
        id: pr
        uses: actions/github-script@v7
        with:
          script: |
            const pr = await github.rest.pulls.get({
              owner: context.repo.owner,
              repo: context.repo.repo,
              pull_number: context.issue.number
            });
            core.setOutput('head_ref', pr.data.head.ref);
      - uses: actions/checkout@v4
        with:
          ref: ${{ steps.pr.outputs.head_ref }}
      - uses: mara-werils/ai-code-reviewer@v1
        env:
          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}

See the full example: examples/on-demand-review.yml

Supported Providers

Use any LLM. Switch providers with one line.

*Estimated for a ~200 line PR.

Provider examples

- uses: mara-werils/ai-code-reviewer@v1
  with:
    provider: 'groq'
  env:
    GROQ_API_KEY: ${{ secrets.GROQ_API_KEY }}

- uses: mara-werils/ai-code-reviewer@v1
  env:
    OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}

- uses: mara-werils/ai-code-reviewer@v1
  with:
    provider: 'anthropic'
  env:
    ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}

- uses: mara-werils/ai-code-reviewer@v1
  with:
    provider: 'google'
  env:
    GOOGLE_API_KEY: ${{ secrets.GOOGLE_API_KEY }}

- uses: mara-werils/ai-code-reviewer@v1
  with:
    provider: 'ollama'
    model: 'llama3.1:8b'
    api_base_url: 'http://your-server:11434/v1'

- uses: mara-werils/ai-code-reviewer@v1
  with:
    api_base_url: 'https://your-api.example.com/v1'
    model: 'your-model'
  env:
    OPENAI_API_KEY: ${{ secrets.YOUR_API_KEY }}

GitLab CI Integration

Works with GitLab merge requests via the CLI. Add to your .gitlab-ci.yml:

ai-code-review:
  stage: test
  image: python:3.11-slim
  rules:
    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
  script:
    - pip install --quiet pr-reviewer
    - pr-reviewer review
        --platform gitlab
        --repo "$CI_PROJECT_PATH"
        --mr "$CI_MERGE_REQUEST_IID"
        --post
  allow_failure: true

Required CI/CD variables: GITLAB_TOKEN (api scope) + your LLM API key (OPENAI_API_KEY, GROQ_API_KEY, etc.)

Works with self-hosted GitLab too — set GITLAB_URL to your instance URL.

See the full template: examples/gitlab-ci.yml

Configuration

Action inputs

- uses: mara-werils/ai-code-reviewer@v1
  with:
    # LLM provider (openai, anthropic, groq, google, ollama)
    provider: 'openai'

    # Specific model (auto-selected per provider if empty)
    model: ''

    # Review style: concise, thorough, minimal
    review_style: 'concise'

    # Max comments per review (1-50)
    max_comments: '15'

    # Review comment language (en, zh, ja, ko, es, de, fr, ru, pt)
    language: 'en'

    # Custom instructions for your team
    custom_instructions: |
      - We use the Repository pattern
      - Flag any direct SQL queries in controllers
      - We handle PII — security is critical

    # Auto-label PRs (bugfix, feature, refactor, etc.)
    label_pr: 'false'

    # Suggest missing tests
    suggest_tests: 'true'

Per-repo config (.pr-reviewer.yml)

Drop this in your repo root for persistent config:

# .pr-reviewer.yml
review_style: thorough
max_comments: 20

custom_instructions: |
  - Our API uses FastAPI with Pydantic v2
  - All new endpoints must have OpenAPI docs
  - We're migrating from callbacks to async/await

ignore_paths:
  - "*.lock"
  - "generated/**"
  - "__snapshots__/**"

ignore_titles:
  - "WIP"
  - "DO NOT MERGE"

CLI

Review PRs locally or in any CI:

pip install pr-reviewer

# Review a GitHub PR
export GITHUB_TOKEN=ghp_...
export OPENAI_API_KEY=sk-...
pr-reviewer review --repo owner/name --pr 42

# Review with a specific provider
pr-reviewer review --repo owner/name --pr 42 --provider groq

# Review a local diff
git diff main..HEAD > changes.diff
pr-reviewer review --diff changes.diff

# Review and post back to GitHub
pr-reviewer review --repo owner/name --pr 42 --post

VS Code Extension

Review code directly in your editor — no PR needed.

Cmd+Shift+R  →  Review current file
Cmd+Shift+D  →  Review uncommitted changes
Right-click  →  Review selection

Install

Search "AI Code Reviewer" in the VS Code Extensions marketplace, or:

cd vscode-extension
npm install && npm run compile
# Then: Cmd+Shift+P → "Developer: Install Extension from Location..." → select vscode-extension/

Configure

Open Settings → search "AI Code Reviewer":

• Provider: openai, anthropic, groq, google, ollama
• API Key: your key (or use env vars)
• Review Style: concise, thorough, minimal

Issues appear in the Problems panel with severity levels (Error, Warning, Info, Hint).

Works with the same providers as the GitHub Action. $0.002/review with Groq, $0.00 with Ollama.

See the full docs: vscode-extension/README.md

Self-Hosted Mode

For teams needing full control, RAG-powered codebase understanding, and persistent analytics.

git clone https://github.com/mara-werils/ai-code-reviewer.git
cd ai-code-reviewer
cp .env.example .env  # Edit with your keys
docker-compose up -d

What you get

Architecture

graph LR
    A[GitHub Webhook] --> B[FastAPI]
    B --> C[Redis Queue]
    C --> D[Review Worker]
    D --> E[Classify PR]
    E --> F[Retrieve Context]
    F --> G[LangGraph Agent]
    G --> H{Tools}
    H --> I[search_codebase]
    H --> J[find_usages]
    H --> K[check_tests]
    H --> L[read_file]
    G --> M[Post Review]
    N[Indexer] --> O[(PostgreSQL + pgvector)]
    F --> O

FAQ

Badge

Show that your project uses AI code reviews:

[![AI Code Review](https://img.shields.io/badge/AI-Code%20Review-blueviolet)](https://github.com/mara-werils/ai-code-reviewer)

Roadmap

• Multi-LLM support (GPT, Claude, Llama, Gemini, Ollama)
• Inline comments with suggested fixes
• On-demand /review command
• Self-hosted mode with RAG
• CLI tool
• Cost estimation
• GitLab integration
• Bitbucket integration
• PR chat — ask questions about the PR
• Auto-fix /fix — AI commits fixes directly to your PR branch
• Learning from feedback
• VS Code extension
• JetBrains plugin
• Slack/Discord notifications

Contributing

Contributions are welcome! See CONTRIBUTING.md for guidelines.

git clone https://github.com/mara-werils/ai-code-reviewer.git
cd ai-code-reviewer
pip install -e ".[dev]"
pytest tests/ -v
ruff check .

License

MIT — use it however you want.