Code Review

GitHub Action that auto-reviews Pull Requests using Google Gemini with DeepSeek fallback.

How It Works

1. Evaluate Diff & Check PR Size — Fetches the PR diff and skips if it's empty or exceeds line/file limits.

2. AI Review — Sends the diff to the primary Gemini model with a structured prompt covering:

   • Critical issues (security, data loss, unhandled exceptions)
   • Performance & scalability (N+1 queries, blocking I/O, inefficient algorithms)
   • Maintainability (SRP violations, debug leftovers, cascading impact)

   If the primary model fails (rate limited, unavailable), it falls back through: Primary Gemini → Fallback Gemini → DeepSeek

3. Post Comment — Publishes the review as a formatted PR comment.

Usage

name: AI Code Review
on:
  pull_request:
    types: [opened, synchronize]

jobs:
  review:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0
      - uses: javedquadri/code-review@main
        with:
          gemini_api_key: ${{ secrets.GEMINI_API_KEY }}

With DeepSeek Fallback

- uses: javedquadri/code-review@main
  with:
    gemini_api_key: ${{ secrets.GEMINI_API_KEY }}
    deepseek_api_key: ${{ secrets.DEEPSEEK_API_KEY }}

Customizing Models

- uses: javedquadri/code-review@main
  with:
    gemini_api_key: ${{ secrets.GEMINI_API_KEY }}
    model: gemini-2.5-pro
    fallback_gemini_model: gemini-2.5-flash
    deepseek_model: deepseek-chat

Inputs

Input	Required	Default	Description
gemini_api_key	Yes	—	Gemini API key from Google AI Studio
deepseek_api_key	No	''	DeepSeek API key for fallback
model	No	gemini-3.5-flash	Primary Gemini model
fallback_gemini_model	No	gemini-2.5-flash	Fallback Gemini model if primary fails
deepseek_model	No	deepseek-v4-flash	DeepSeek model for final fallback
tech_stack	No	''	Tech stack description (e.g. Python/Django). Leave blank for auto-detection
max_changed_lines	No	3000	Skip review if total changed lines exceeds this
max_changed_files	No	60	Skip review if changed files exceeds this

Fallback Chain

1. Primary Gemini (model) — first attempt
2. Fallback Gemini (fallback_gemini_model) — tried if primary fails (rate limits with 5s pause, 500/503, or other errors)
3. DeepSeek (deepseek_model) — final attempt, only if deepseek_api_key is provided

If all providers fail, a message is posted asking reviewers to proceed manually.

Permissions

The action needs these permissions in your workflow:

permissions:
  contents: read      # To fetch the PR diff
  pull-requests: write # To post review comments

Requirements

• actions/checkout@v4 with fetch-depth: 0 (needs full git history to diff)
• Triggered by pull_request events (opened, synchronize)