What is Mcp Server Wrapper

MCP Server Wrapper is a tool designed to act as a wrapper around an MCP server, allowing users to selectively expose specific tools to the MCP client. It helps manage which tools are available, particularly for use with the Cursor editor.

Use cases

Use cases include customizing the toolset available to the Cursor editor, managing tool exposure for LLM interactions, and developing applications that require specific tool functionalities without exposing all server capabilities.

How to use

To use MCP Server Wrapper, first install Deno. You can install the wrapper via the command line using ‘deno install jsr:@dpirate/mcp-server-wrapper’ or clone the repository for local development. For CLI usage, run ‘deno run -A jsr:@dpirate/mcp-server-wrapper/cli YOUR_MCP_SERVER_URL YOUR_TOOL_NAME_1 YOUR_TOOL_NAME_2 …’ with the appropriate parameters.

Key features

Key features include the ability to select which tools to expose, segregate read and write tools for better control over LLM behavior, and support for stdio, ‘tools’ feature, deno, jsr, and npm packages.

Where to use

MCP Server Wrapper can be used in software development environments, particularly where integration with LLMs and tool management is necessary, such as in coding editors or automated workflows.

MCP Server Wrapper

A wrapper around a MCP server to select which tools to expose to mcp client.

I created this mainly to:

• select which tools to expose to Cursor(my editor of choice)
  • often times I do not use all the tools of a server
  • sometimes I do not want to expose some tools to the LLM
  • stay within limit for number of tools in Cursor
• segregate tools that read a resource from tools that write to a resource, that way I can better control llm behavior

Right now it only supports stdio, “tools” feature, deno, jsr and npm packages. I plan to add support for other transports and mcp features in the future.

Does not support passing arguments to the wrapped server. Will be fixed in the future.

Why deno? Just curious.

Installation

First Install deno if you don’t have it.

You need to install this package only if you want to use it programmatically. For CLI usage, you can run it directly from jsr.

Install via jsr

deno install jsr:@dpirate/mcp-server-wrapper

Install via git (for local development)

# Clone the repository
git clone https://github.com/your-username/mcp-server-wrapper.git
cd mcp-server-wrapper

Usage

CLI Usage

You can add the command directly to your mcp.json config.

From jsr

deno run -A jsr:@dpirate/mcp-server-wrapper/cli YOUR_MCP_SERVER_URL YOUR_TOOL_NAME_1 YOUR_TOOL_NAME_2 ...

From local installation

deno run -A PATH_TO_LOCAL_INSTALLATION/src/cli.ts YOUR_MCP_SERVER_URL YOUR_TOOL_NAME_1 YOUR_TOOL_NAME_2 ...

Where:

• YOUR_MCP_SERVER_URL can be:
  • A local file path (e.g., ./my-server.ts or /path/to/server.js)
  • A JSR package (e.g., jsr:@username/package-name)
  • An NPM package (e.g., npm:package-name)
• YOUR_TOOL_NAME_1, YOUR_TOOL_NAME_2, etc. are the names of the tools you want to expose from the original server

Note: You need to add prefix jsr: or npm: to the server url.

Programmatic Usage

import { MCPServerWrapper } from "jsr:@username/mcp-server-wrapper";

const wrapper = new MCPServerWrapper({
  serverUrl: "./my-server.ts",
  allowedTools: ["tool1", "tool2"],
});

// Start the wrapper
await wrapper.start();

// To stop the wrapper
await wrapper.stop();

Examples

Filtering GitHub API Tools

# Only expose the 'search-repo' and 'list-issues' tools from a local GitHub API server
deno run -A jsr:@dpirate/mcp-server-wrapper/cli ./github-api-server.ts search-repo list-issues

Wrapping Package Servers

# Only expose specific tools from an npm package
deno run -A jsr:@dpirate/mcp-server-wrapper/cli npm:@modelcontextprotocol/server-memory search_nodes read_graph

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

This project is licensed under the MIT License.