Code Lens

Code Lens MCP Server

Gemini-powered MCP server for automated code review, analysis, and documentation.

Overview

Code Lens is a Model Context Protocol server that uses Google Gemini to analyze diffs, review pull requests, detect code smells, generate documentation, and verify logic. It exposes 13 tools, 7 resources, and 5 prompts over stdio transport.

Key Features

• PR review pipeline — generate diffs, assess impact, detect breaking API changes, and produce review summaries with merge recommendations
• File analysis — load any source file for refactoring suggestions, code smell detection, documentation generation, and natural-language Q&A
• Logic verification — verify algorithms using Gemini's code execution sandbox
• Structured outputs — all tools return validated JSON via Zod v4 output schemas
• Web search — Google Search with Grounding for up-to-date information retrieval
• Task lifecycle support — every tool except load_file can run via MCP tasks with polling, cancellation, and progress updates

Requirements

• Node.js >= 24
• A Gemini API key (GEMINI_API_KEY or GOOGLE_API_KEY)

Quick Start

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

Docker

docker run -i --rm -e GEMINI_API_KEY="your-api-key" ghcr.io/j0hanz/code-lens

Or with Docker Compose:

GEMINI_API_KEY=your-api-key docker compose up

Client Configuration

Install in VS Code

Add to .vscode/mcp.json:

{

"servers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

Or install via CLI:

code --add-mcp '{"name":"code-lens","command":"npx","args":["-y","@j0hanz/code-lens-mcp@latest"]}'

For more info, see VS Code MCP docs.

Install in VS Code Insiders

Add to .vscode/mcp.json:

{

"servers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

Or install via CLI:

code-insiders --add-mcp '{"name":"code-lens","command":"npx","args":["-y","@j0hanz/code-lens-mcp@latest"]}'

For more info, see VS Code Insiders MCP docs.

Install in Cursor

Add to ~/.cursor/mcp.json:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Cursor MCP docs.

Install in Visual Studio

Add to mcp.json:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Visual Studio MCP docs.

Install in Goose

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Goose MCP docs.

Install in LM Studio

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see LM Studio MCP docs.

Install in Claude Desktop

Add to claude_desktop_config.json:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Claude Desktop MCP docs.

Install in Claude Code

claude mcp add code-lens -- npx -y @j0hanz/code-lens-mcp@latest

Or add to config:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Claude Code MCP docs.

Install in Windsurf

Add to ~/.codeium/windsurf/mcp_config.json:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Windsurf MCP docs.

Install in Amp

amp mcp add code-lens -- npx -y @j0hanz/code-lens-mcp@latest

Or add to config:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Amp MCP docs.

Install in Cline

Add to cline_mcp_settings.json:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Cline MCP docs.

Install in Codex CLI

Add to ~/.codex/config.yaml:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Codex CLI MCP docs.

Install in GitHub Copilot

Add to .vscode/mcp.json:

{

"servers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see GitHub Copilot MCP docs.

Install in Warp

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Warp MCP docs.

Install in Kiro

Add to .kiro/settings/mcp.json:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see Kiro MCP docs.

Install in Gemini CLI

Add to ~/.gemini/settings.json:

{

"mcpServers": { "code-lens": { "command": "npx", "args": ["-y", "@j0hanz/code-lens-mcp@latest"], "env": { "GEMINI_API_KEY": "your-api-key" } } } }

For more info, see [Gemini CLI MCP docs](https://github.com/google-gemini