gemini-review

# Via npm (recommended)
npm install -g @google/gemini-cli
 
# Via Homebrew (macOS)
brew install gemini-cli
 
# Or run without installing
npx @google/gemini-cli
 
# Verify installation
gemini --version

# Requires Gemini CLI v0.4.0+
gemini extensions install https://github.com/gemini-cli-extensions/code-review
 
# Verify extension
gemini extensions list

# Run gemini and follow browser login
gemini
 
# Select: "Login with Google Account"
# Opens browser for OAuth

# Get API key from https://aistudio.google.com/apikey
 
# Set environment variable
export GEMINI_API_KEY="your-api-key"
 
# Or add to shell profile
echo 'export GEMINI_API_KEY="your-api-key"' >> ~/.zshrc
 
# Run Gemini
gemini

# For Google Cloud projects
export GOOGLE_API_KEY="your-api-key"
export GOOGLE_GENAI_USE_VERTEXAI=true
export GOOGLE_CLOUD_PROJECT="your-project-id"
 
gemini

# Start Gemini CLI
gemini
 
# Run code review on current branch
/code-review

# In interactive mode
gemini
 
# Then ask:
> Review the changes in this branch for bugs and security issues
> Analyze src/api/users.ts for potential vulnerabilities
> What are the code quality issues in the last 3 commits?

# Simple prompt execution
gemini -p "Review the code changes for bugs and security issues"
 
# With JSON output (for parsing)
gemini -p "Review the changes" --output-format json
 
# Stream JSON events (real-time)
gemini -p "Review and fix issues" --output-format stream-json
 
# Specify model
gemini -m gemini-2.5-pro -p "Deep code review of this PR"

# Get diff and review
git diff origin/main...HEAD > diff.txt
 
gemini -p "Review this code diff for:
1. Security vulnerabilities
2. Performance issues
3. Code quality problems
4. Missing error handling
 
Diff:
$(cat diff.txt)
" --output-format json > review.json

# Track token usage and costs
gemini -p "Review changes" --session-summary metrics.json
 
# View metrics
cat metrics.json

/gemini review     # Request code review
/gemini summary    # Get PR summary
/gemini help       # Show available commands

# .github/workflows/gemini-review.yml
name: Gemini 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
 
      - name: Setup Node.js
        uses: actions/setup-node@v4
        with:
          node-version: '20'
 
      - name: Install Gemini CLI
        run: npm install -g @google/gemini-cli
 
      - name: Run Review
        env:
          GEMINI_API_KEY: ${{ secrets.GEMINI_API_KEY }}
        run: |
          # Get diff
          git diff origin/${{ github.base_ref }}...HEAD > diff.txt
 
          # Run Gemini review
          gemini -p "Review this pull request diff for bugs, security issues, and code quality problems. Be specific about file names and line numbers.
 
          $(cat diff.txt)" > review.md
 
      - name: Post Review Comment
        uses: actions/github-script@v7
        with:
          script: |
            const fs = require('fs');
            const review = fs.readFileSync('review.md', 'utf8');
            github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
              body: `## 🤖 Gemini Code Review\n\n${review}`
            });

# .github/workflows/gemini-review.yml
name: Gemini Code Review
 
on:
  pull_request:
    types: [opened, synchronize]
  issue_comment:
    types: [created]
 
jobs:
  review:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      pull-requests: write
      issues: write
 
    steps:
      - uses: actions/checkout@v4
 
      - name: Run Gemini CLI
        uses: google-github-actions/run-gemini-cli@v1
        with:
          gemini_api_key: ${{ secrets.GEMINI_API_KEY }}
          prompt: "Review this pull request for code quality, security issues, and potential bugs."

@gemini-cli /review
@gemini-cli explain this code change
@gemini-cli write unit tests for this component

# .gitlab-ci.yml
gemini-review:
  image: node:20
  stage: review
  script:
    - npm install -g @google/gemini-cli
    - |
      gemini -p "Review the merge request changes for bugs, security issues, and code quality" > review.md
    - cat review.md
  artifacts:
    paths:
      - review.md
  rules:
    - if: $CI_PIPELINE_SOURCE == "merge_request_event"
  variables:
    GEMINI_API_KEY: $GEMINI_API_KEY

# ~/.gemini/settings.json
{
  "model": "gemini-2.5-pro",
  "theme": "dark",
  "sandbox": true
}

# Project Context for Gemini
 
## Tech Stack
- TypeScript with strict mode
- React 18 with hooks
- FastAPI backend
- PostgreSQL database
 
## Code Review Focus Areas
1. Type safety - ensure proper TypeScript types
2. React hooks rules - check for dependency array issues
3. SQL injection - verify parameterized queries
4. Authentication - check all endpoints have proper auth
 
## Conventions
- Use camelCase for variables
- Use PascalCase for components
- All API errors should use AppError class

# Interactive
gemini                          # Start interactive mode
/code-review                    # Run code review extension
 
# Headless
gemini -p "prompt"              # Single prompt, exit
gemini -p "prompt" --output-format json   # JSON output
gemini -m gemini-2.5-flash -p "prompt"    # Use faster model
 
# Extensions
gemini extensions list          # List installed
gemini extensions install URL   # Install extension
gemini extensions update        # Update all
 
# Key Flags
--output-format json            # Structured output
--output-format stream-json     # Real-time events
--session-summary FILE          # Track metrics
-m MODEL                        # Select model