/gemini-review Command

Quick, explicit Gemini review with sensible defaults and structured output.

Syntax

/gemini-review [file-pattern] [--model flash|pro] [--focus area]

Arguments

file-pattern (optional)

• File path, glob pattern, or directory to review
• If omitted: Reviews git staged files (git diff --cached --name-only)
• Examples: src/auth/*, src/auth/login.js, tests/*.test.js

--model (optional)

• Model to use for review
• Options: flash (fast, default) or pro (thorough)
• Default: gemini-2.5-flash

--focus (optional)

• Specific area to focus review on
• Examples: security, performance, maintainability, testing
• Default: General code quality review

How It Works

When user invokes this command:

1. Parse Arguments

   • Extract file pattern (or use git staged files)
   • Determine model (Flash or Pro)
   • Identify focus area if specified

2. Validate Files

   • Check gemini-cli is installed and authenticated
   • Verify files exist and are accessible
   • Filter out binary/build files

3. Construct Prompt

   • Build focused Gemini prompt based on review type
   • Include @ file references
   • Add focus-specific criteria if --focus provided

4. Execute Review

   • Call gemini-cli with --output-format json
   • Use specified model (--model flag)
   • Capture structured JSON response

5. Parse Results

   • Extract review findings from JSON
   • Extract token usage statistics
   • Parse for errors, warnings, suggestions

6. Format Output

   • Display file-by-file breakdown
   • Show severity levels (✓ OK, ⚠ Warning, ❌ Error)
   • Present actionable recommendations
   • Show token usage at bottom

Examples

Review Git Staged Files

/gemini-review

Behavior: Reviews all files in git staging area

Review Specific Files

/gemini-review src/auth/login.js src/auth/session.js

Behavior: Reviews just those two files

Review with Pattern

/gemini-review src/auth/*

Behavior: Reviews all files in src/auth/

Deep Review with Pro

/gemini-review src/auth/* --model pro

Behavior: Uses gemini-2.5-pro for thorough review

Security-Focused Review

/gemini-review src/api/* --focus security

Behavior: Reviews API files with security-specific criteria

Performance Review

/gemini-review src/services/processor.js --model pro --focus performance

Behavior: Deep performance analysis with Pro model

Implementation

When Claude processes this command:

# 1. Determine files to review
if [[ -n "$file_pattern" ]]; then
    files="$file_pattern"
else
    # Use git staged files
    files=$(git diff --cached --name-only | grep -E '\.(js|ts|py|java|go|rb)$' | head -10)
    if [[ -z "$files" ]]; then
        echo "No staged files found. Specify files to review."
        exit 1
    fi
fi

# 2. Determine model
model="${model_arg:-gemini-2.5-flash}"

# 3. Build prompt based on focus
if [[ "$focus" == "security" ]]; then
    prompt="Perform a security review focusing on:
- SQL injection vulnerabilities
- XSS vulnerabilities
- Authentication/authorization issues
- Input validation
- Sensitive data exposure

Files: @$files"
elif [[ "$focus" == "performance" ]]; then
    prompt="Review for performance issues:
- Algorithm efficiency
- Memory usage
- Database query optimization
- Caching opportunities
- Bottlenecks

Files: @$files"
else
    # General review
    prompt="Review this code for:
- Correctness and logic errors
- Code quality and maintainability
- Potential bugs and edge cases
- Best practices

Files: @$files"
fi

# 4. Execute with JSON output
result=$(gemini -m "$model" -p "$prompt" --output-format json 2>&1)

# 5. Parse JSON (with fallback)
if echo "$result" | jq . > /dev/null 2>&1; then
    response=$(echo "$result" | jq -r '.response')
    tokens=$(echo "$result" | jq -r '.stats.models | to_entries | map(.value.tokens.total) | add // 0')
else
    # Fallback to text if JSON parsing fails
    echo "Warning: JSON parsing failed, using text output"
    result=$(gemini -m "$model" -p "$prompt" --output-format text)
    response="$result"
    tokens="N/A"
fi

# 6. Format and display results
echo "Gemini Review Results"
echo "===================="
echo ""
echo "$response"
echo ""
echo "---"
echo "Model: $model"
echo "Tokens used: $tokens"

Output Format

Gemini Review Results
====================

src/auth/login.js:
  ✓ Password hashing implementation looks secure
  ⚠️  Line 42: Consider adding rate limiting for login attempts
  ⚠️  Line 67: Missing error handling for database connection failures

src/auth/session.js:
  ✓ Session management follows best practices
  ❌ Line 89: Session token stored in plain text (use httpOnly cookies)

src/auth/tokens.js:
  ✓ JWT implementation is correct
  ⚠️  Line 123: Token expiration should be configurable

Summary:
  Files reviewed: 3
  Errors: 1
  Warnings: 3
  Clean checks: 3

Recommendations:
  1. Fix session token storage (critical security issue)
  2. Add rate limiting to prevent brute force attacks
  3. Make token expiration configurable
  4. Add database error handling

---
Model: gemini-2.5-flash
Tokens used: 4,523

Error Handling

No files found:

Error: No files to review
- If using default (staged files): No files are currently staged
- If using pattern: No files match pattern 'src/nonexistent/*'

Try:
  - Stage files with: git add <files>
  - Specify explicit file pattern: /gemini-review src/**/*.js

gemini-cli not found:

Error: gemini-cli not installed

Install:
  pip install gemini-cli

Setup:
  gemini auth login

Docs: https://github.com/bgreenwell/claude-plugins/tree/main/gemini-review

Authentication error:

Error: gemini-cli not authenticated

Run one of:
  gemini auth login
  gemini config set api_key YOUR_API_KEY

Then retry: /gemini-review

Best Practices

For Claude:

• Always validate gemini-cli is installed before calling
• Use JSON output for structured parsing
• Show token usage to help users track costs
• Format output clearly with visual indicators (✓ ⚠️ ❌)
• Provide actionable recommendations, not just problems
• If reviewing 5+ files, suggest /gemini-batch-review instead

For Users:

• Use default (staged files) for pre-commit reviews
• Use --model pro for critical security reviews
• Use --focus to get targeted feedback
• Review files in logical groups (by feature/module)
• Don't review too many files at once (use batch command for that)

When to Use This Command

Good Use Cases:

• Quick review before commit
• Validate specific file changes
• Get targeted feedback (--focus)
• Repeatable review workflow
• When you want explicit control over what's reviewed

Use Natural Language Instead When:

• Want Claude's analysis + Gemini's perspective
• Need discussion/Q&A about findings
• Complex, nuanced requirements
• Want conversational interaction

Use /gemini-batch-review Instead When:

• Reviewing 5+ files
• Need progress visibility
• Processing multiple directories
• Batch workflow

Notes

• Default model is Flash (faster, cheaper)
• Use Pro for critical/complex reviews
• Token usage shown helps track costs
• Supports all file types Gemini can read
• Max ~10 files recommended (use batch for more)