MCP Tools

Install MCP Server npm version Node.js License: MIT Docker

Enables agents to quickly find and edit code in a codebase with surgical precision. Find symbols, edit them everywhere.

📋 Table of Contents

🚀 Quick Start

Option 1: NPX (Recommended)

Add this to ~/.cursor/mcp.json for Cursor, ~/.config/claude_desktop_config.json for Claude Desktop.

{ "mcpServers": { "mcp-files": { "command": "npx", "args": ["-y", "mcp-files"] } } }

Option 2: Docker

{ "mcpServers": { "mcp-files": { "command": "docker", "args": [ "run", "--rm", "-i", "flesler/mcp-files" ] } } }

Option 3: HTTP transport

First run the server:

TRANSPORT=http PORT=3000 npx mcp-files

Then:

{ "mcpServers": { "mcp-files": { "type": "streamableHttp", "url": "http://localhost:3000/mcp" } } }

🛠️ Available Tools

Tool	Description	Parameters
`read_symbol`	Find and extract code blocks by symbol name(s) from files. Supports multiple symbols via array	`symbols` (string[]), `file_paths[]?` , `limit?` , `optimize?`
`import_symbol`	Import and inspect JavaScript/TypeScript modules and their properties	`module_path` , `property?`
`search_replace`	Search and replace with intelligent whitespace handling and automation-friendly multiple match resolution	`file_path` , `old_string` , `new_string` , `allow_multiple_matches?`
`insert_text`	Insert/replace text at precise line ranges. Perfect for direct line operations from code citations (12:15:file.ts) and surgical edits in large files	`file_path` , `from_line` , `text` , `to_line`
`os_notification`	Send OS notifications using native notification systems	`message` , `title?`

⚡ Surgical Code Editing: Surgical Precision

The combination of read_symbol + insert_text unlocks revolutionary code editing capabilities that transform how AI agents work with codebases.

🎯 The Power Combo

1. Symbol Discovery ( - Find ANY symbol(s) ANYWHERE in your codebase:

// Find single function/class/interface anywhere in repo read_symbol({symbols: ["generateApiKey"]}) // → Returns: exact location (lines 45-52 in src/auth/tokens.ts) // Find multiple symbols at once read_symbol({symbols: ["User", "UserService", "UserInterface"]}) // → Returns: all matching symbols with their locations // Optimize code for AI context (strips comments, normalizes indentation) read_symbol({symbols: ["complexFunction"], optimize: true}) // → Returns: clean, tab-indented code without comments for AI processing

2. Surgical Editing ( - Make precise modifications using exact line ranges:

// Replace specific lines with surgical precision insert_text(file: "src/auth/tokens.ts", from_line: 45, to_line: 52, text: "improved implementation") // Insert new code without disruption insert_text(file: "src/auth/tokens.ts", from_line: 45, text: "// Added security enhancement")

🚀 Superpowers Unlocked

🔍 Cross-Codebase Intelligence

Find any symbol across entire repositories instantly
No manual searching through files and folders
Perfect accuracy even in massive codebases

✂️ Precision Surgery

Edit exact functions, classes, or code blocks
Replace implementations without affecting surrounding code
Insert enhancements at perfect locations

🎛️ Zero-Error Refactoring

Update function signatures everywhere they exist
Modify APIs across all files simultaneously
Fix bugs with surgical precision across entire codebase

💡 Real-World Magic

# Find and enhance any function read_symbol("validateEmail") → lines 23-35 in utils/validation.ts insert_text(from_line: 23, to_line: 35, text: "enhanced validation with regex") # Add documentation to any symbol read_symbol("processPayment") → line 87 in payment/processor.ts insert_text(from_line: 87, text: "/** Secure payment processing with fraud detection */") # Fix bugs anywhere in codebase read_symbol("parseUserInput") → lines 156-162 in input/parser.ts insert_text(from_line: 156, to_line: 162, text: "sanitized parsing logic")

This transforms AI from "helpful assistant" to "surgical code surgeon" 🦾

🎛️ Environment Variables

Variable	Default	Description
`TRANSPORT`	`stdio`	Transport mode: `stdio` or `http`
`PORT`	`4657`	HTTP server port (when `TRANSPORT=http` )
`DEBUG`	`false`	Enable debug mode and `utils_debug` tool

🖥️ Server Usage

You can either install and use mcp-files or npx mcp-files.

# Show help mcp-files --help # Default: stdio transport mcp-files # HTTP transport TRANSPORT=http mcp-files TRANSPORT=http PORT=8080 mcp-files # With debug mode DEBUG=true mcp-files

💻 CLI Usage

All tools can be used directly from the command line:

# Find single symbol in code (specific file) mcp-files read_symbol "MyInterface" src/types.ts # Find multiple symbols at once (comma-separated) mcp-files read_symbol "User,UserService,UserInterface" src/ # Find symbol in current directory (default) mcp-files read_symbol "MyInterface" # Use wildcards for pattern matching mcp-files read_symbol "get*,User*" src/ # Inspect imports mcp-files import_symbol lodash get # Replace text with smart whitespace handling mcp-files replace_text config.json "old_value" "new_value" # Send notifications mcp-files os_notification "Task completed"

🏗️ Architecture

Type-safe tools with Zod validation
Self-contained modules in src/tools/
Cross-platform support (Linux, macOS, Windows, WSL)
Performance optimized with memoization
Clear error handling with descriptive messages

🧪 Development

# Install dependencies npm install # Build npm run build # Development mode npm run dev # Lint npm run lint:full # Test npm run ts test/index.test.ts # CLI testing node dist/index.js read_symbol "functionName" file.ts # Multiple symbols (comma-separated in CLI) node dist/index.js read_symbol "func1,func2,Class*" file.ts # Or search current directory node dist/index.js read_symbol "functionName"

🧹 Code Optimization

The read_symbol tool includes an optimize parameter that cleans up code for AI processing:

What it does:

Strips comments: Removes //, /* */, and /** */ comments
Collapses newlines: Multiple consecutive newlines become single newlines
Normalizes indentation: Converts spaces to tabs (detects indentation token size automatically)
Removes base indentation: Eliminates common leading whitespace

Usage:

// MCP mode - explicit control read_symbol({symbols: ["MyClass"], optimize: true}) // optimized read_symbol({symbols: ["MyClass"], optimize: false}) // raw code (default) // CLI mode - always optimized mcp-files read_symbol "MyClass" src/

Perfect for: Reducing token count in AI context windows while preserving code structure and readability.

🛠️ Troubleshooting

Requirements

Node.js ≥20 - This package requires Node.js version 20 or higher

Common Issues

ERR_MODULE_NOT_FOUND when running

Problem: Error like Cannot find module '@modelcontextprotocol/sdk/dist/esm/server/index.js' when running npx mcp-files
Cause: Corrupt or incomplete npx cache preventing proper dependency resolution
Solution: Clear the npx cache and try again:
npx clear-npx-cache npx mcp-files
Note: This issue can occur on both Node.js v20 and v22, and the cache clear resolves it

Tools not showing up in MCP client:

Verify Node.js version is 20 or higher
Try restarting your MCP client after configuration changes

File operations failing:

Ensure proper file permissions for the files you're trying to read/modify
Use absolute paths when possible for better reliability
Check that the target files exist and are accessible

📝 License

MIT - see LICENSE file.

🔗 Links

Built for AI agents 🤖

MCP Files