Gemini Codebase Analysis Skill

Analyze entire codebases using Gemini 2.5 Pro's massive context window (1M+ tokens). This skill collects repository files, sends them to Gemini for analysis, and returns comprehensive technical insights.

Prerequisites

1. API Key: Set your Gemini API key:

   bashCopy

   export GEMINI_API_KEY="your-api-key"
   

2. Python SDK: Install the Google GenAI SDK:

   bashCopy

   pip install google-genai
   

Usage

Basic Analysis with Custom Query

python /Users/jms/.claude/skills/gemini-codebase-analysis/gemini_codebase_analyzer.py /path/to/repo "Your question about the codebase"

Using Analysis Templates

Available templates:

• architecture - Full architectural analysis
• security - Security vulnerability assessment
• performance - Performance analysis
• quality - Code quality assessment
• dependencies - Dependency analysis
• onboarding - Developer onboarding guide

# Architecture analysis
python /Users/jms/.claude/skills/gemini-codebase-analysis/gemini_codebase_analyzer.py /path/to/repo --template architecture

# Security audit
python /Users/jms/.claude/skills/gemini-codebase-analysis/gemini_codebase_analyzer.py /path/to/repo --template security

Save Output to File

python /Users/jms/.claude/skills/gemini-codebase-analysis/gemini_codebase_analyzer.py /path/to/repo --template architecture -o analysis.md

JSON Output (for programmatic use)

python /Users/jms/.claude/skills/gemini-codebase-analysis/gemini_codebase_analyzer.py /path/to/repo "question" --json

Options

What Gets Analyzed

The analyzer collects:

• Source code files (.py, .js, .ts, .java, .go, .rs, etc.)
• Config files (.json, .yaml, .toml, etc.)
• Documentation (.md, .rst, .txt)
• Build/DevOps files (Dockerfile, Makefile, etc.)

Automatically excluded:

• .git, node_modules, vendor, venv
• Binary files, images, videos
• Lock files, build outputs
• Files > 500KB, total context > 50MB

Example Queries

Architecture

• "How is the application structured?"
• "What design patterns are used?"
• "How does data flow through the system?"

Security

• "Are there any security vulnerabilities?"
• "How is authentication implemented?"
• "Are secrets properly managed?"

Performance

• "Where are the potential bottlenecks?"
• "Are there any N+1 query issues?"
• "How is caching implemented?"

Understanding

• "How does the [X] feature work?"
• "What happens when a user [action]?"
• "How are [X] and [Y] connected?"

Integration with Claude Code

After running the analyzer, the output can be:

1. Printed directly for immediate review
2. Saved to a file for reference
3. Output as JSON for further processing

The analysis results are designed to be consumed by Claude Code for:

• Answering follow-up questions
• Generating implementation plans
• Identifying specific code changes needed