Filesystem MCP Server

What is this?

The Filesystem MCP Server (@modelcontextprotocol/server-filesystem) is a specialized Model Context Protocol server for secure, sandboxed file management on a local filesystem. It exposes a standardized set of tools for browsing directories, reading and writing files, applying glob-style filters, and streaming large file contents—all within a configurable root directory. Implemented in TypeScript and published as a reusable npm package, it bridges the gap between AI agents and real-world codebases, documentation sets, or data repositories in your development workflows.

Under the hood, it serves HTTP or WebSocket endpoints that map MCP RPC routes to file system operations, guarded by a configuration layer enforcing root-path constraints, allow-lists, and block-lists. Core capabilities include full CRUD on files and directories, efficient chunked streaming reads, glob filtering, metadata fetching, and extension hooks for custom authorization, logging, or transformations. This makes it ideal for embedding in IDE plugins, CI/CD pipelines, or autonomous scripts that require safe and reliable file access.

Quick Start

Install the server using npm:

npm install @modelcontextprotocol/server-filesystem

Then add it to your MCP client configuration:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": ["-y", "@modelcontextprotocol/server-filesystem"],
      "env": {
        "API_KEY": "your-api-key-here"
      }
    }
  }
}

Key Features

Feature 1: Sandbox Safety – All file operations are confined to a specified root directory to prevent unauthorized access to system files.

Feature 2: Glob-style Filtering – Include or exclude files and directories using powerful glob patterns for precise control over the file set.

Feature 3: Streaming Support – Efficiently read large files in configurable chunks to minimize memory usage and support backpressure-aware processing.

Example Usage

When building an AI assistant to summarize your codebase, you can list all TypeScript files recursively and then read snippets from each file:

// Example code
const result = await client.callTool({
  name: "listDirectory",
  arguments: {
    path: ".",
    recursive: true,
    include: ["**/*.ts"],
    exclude: ["**/node_modules/**"]
  }
});

for (const entry of result.entries) {
  const snippet = await client.callTool({
    name: "readFile",
    arguments: { path: entry.path, encoding: "utf-8", length: 200 }
  });
  console.log(`File: ${entry.path}\nSnippet:\n${snippet.content}\n---`);
}

This code lists all .ts files under the current directory, reads the first 200 characters of each file, and logs them—helpful for quick code summaries or previews.

Configuration

The server accepts the following environment variables:

API_KEY – A valid API key for authenticating with your MCP deployment.

MAX_GLOB_DEPTH (optional) – Limits the recursion depth when listing directories (default is no limit).

Available Tools/Resources

listDirectory: Recursively or non-recursively lists directory contents with include/exclude patterns and depth control.

readFile: Reads a file’s full content or a specified length, with optional encoding and streaming support.

Who Should Use This?

This server is perfect for:

Use case 1: Software engineers automating file manipulations and code generation in CI/CD pipelines.

Use case 2: AI researchers integrating real project files into analysis or code-completion workflows.

Use case 3: Documentation teams generating summaries or indexing large documentation trees.

Conclusion

The Filesystem MCP Server offers a safe, extensible bridge between AI agents and your local filesystem, enabling intelligent file browsing, streaming, and modifications within a secure sandbox. Give it a try to simplify your agentic workflows and supercharge your development pipelines.

Check out the GitHub repository for more information and to contribute.