ABOUTME: Local code review skill using Gemini CLI for pre-commit reviews

ABOUTME: Supports staged, uncommitted, or branch diff with configurable prompts

Gemini Review - Local Code Review

MANDATORY: Always use --model gemini-3.1-pro-preview. No other model. No fallback. No substitution.

Trigger

Activate when user says: "gemini review", "review with gemini", "local review", or /gemini-review.

Options

Option	Description	Default
--all	Review all uncommitted changes	staged only
--branch [base]	Review current branch vs base	main
--prompt <name>	Use specific prompt template	default
--extension	Use Gemini's built-in /code-review	custom prompt

Execution Flow

Step 1: Determine diff scope

# Default: staged changes
git diff --cached

# With --all: all uncommitted
git diff HEAD

# With --branch [base]: branch vs base (default base: main)
git diff main...HEAD

Step 2: Check if there are changes to review

# Check if diff is empty
git diff --cached --quiet && echo "No staged changes" || echo "Has changes"

If no changes, inform user and suggest:

• git add <files> to stage changes
• --all flag for uncommitted changes
• --branch flag for branch review

Step 3: Load prompt template

Prompt templates are in ~/.claude/skills/gemini-review/prompts/:

• default.md - Concise review focused on bugs/security/performance
• ci-style.md - Detailed review matching CI pipeline style

Step 4: Execute review

Option A - Using built-in extension (with --extension flag):

cd <project_root>
gemini --model gemini-3.1-pro-preview --yolo "/code-review"

Option B - Using custom prompt (default):

cd <project_root>

# Generate diff
DIFF=$(git diff --cached)

# Read prompt template
PROMPT=$(cat ~/.claude/skills/gemini-review/prompts/default.md)

# Invoke Gemini with prompt and diff
gemini --model gemini-3.1-pro-preview --yolo <<EOF
$PROMPT

## Code Changes to Review

\`\`\`diff
$DIFF
\`\`\`
EOF

Step 5: Present results

Gemini's output will appear in the terminal. Summarize key findings for the user.

Quality Notes

• Review the full diff carefully before sending to Gemini
• Summarize findings thoughtfully; do not just relay raw output
• Flag false positives rather than forwarding everything

Important Notes

1. Always run from project root - Gemini needs project context
2. Check for CLAUDE.md/GEMINI.md - Include project guidelines in prompt if present
3. Large diffs - For very large diffs (>10000 lines), suggest --branch with specific files
4. Exit codes - Gemini CLI returns 0 on success, non-zero on error

Troubleshooting

Issue	Solution
"No staged changes"	Run git add <files> or use --all
"gemini: command not found"	Install Gemini CLI: see https://github.com/google-gemini/gemini-cli
API errors	Check GEMINI_API_KEY is set
Timeout on large diffs	Split into smaller reviews or use --extension