Using Gemini CLI for Large Codebase Analysis

When analyzing large codebases or multiple files that might exceed context limits, use the Gemini CLI with its massive context window. Use gemini -p to leverage Google Gemini's large context capacity.

File and Directory Inclusion Syntax

Use the @ syntax to include files and directories in your Gemini prompts. The paths should be relative to WHERE you run the gemini command:

Examples:

Single file analysis:

gemini -p "@src/main.py Explain this file's purpose and structure"

Multiple files:

gemini -p "@package.json @src/index.js Analyze the dependencies used in the code"

Entire directory:

gemini -p "@src/ Summarize the architecture of this codebase"

Multiple directories:

gemini -p "@src/ @tests/ Analyze test coverage for the source code"

Current directory and subdirectories:

gemini -p "@./ Give me an overview of this entire project"
# Or use --all_files flag:
gemini --all_files -p "Analyze the project structure and dependencies"

Implementation Verification Examples

Check if a feature is implemented:

gemini -p "@src/ @lib/ Has dark mode been implemented in this codebase? Show me the relevant files and functions"

Verify authentication implementation:

gemini -p "@src/ @middleware/ Is JWT authentication implemented? List all auth-related endpoints and middleware"

Check for specific patterns:

gemini -p "@src/ Are there any React hooks that handle WebSocket connections? List them with file paths"

Verify error handling:

gemini -p "@src/ @api/ Is proper error handling implemented for all API endpoints? Show examples of try-catch blocks"

Check for rate limiting:

gemini -p "@backend/ @middleware/ Is rate limiting implemented for the API? Show the implementation details"

Verify caching strategy:

gemini -p "@src/ @lib/ @services/ Is Redis caching implemented? List all cache-related functions and their usage"

Check for specific security measures:

gemini -p "@src/ @api/ Are SQL injection protections implemented? Show how user inputs are sanitized"

Verify test coverage for features:

gemini -p "@src/payment/ @tests/ Is the payment processing module fully tested? List all test cases"

When to Use Gemini CLI

Use gemini -p when:

Analyzing entire codebases or large directories
Comparing multiple large files
Need to understand project-wide patterns or architecture
Current context window is insufficient for the task
Working with files totaling more than 100KB
Verifying if specific features, patterns, or security measures are implemented
Checking for the presence of certain coding patterns across the entire codebase

Important Notes

Paths in @ syntax are relative to your current working directory when invoking gemini
The CLI will include file contents directly in the context
No need for --yolo flag for read-only analysis
Gemini's context window can handle entire codebases that would overflow Claude's context
When checking implementations, be specific about what you're looking for to get accurate results