WASM MCP Server
A proof-of-concept implementation of a Model Context Protocol (MCP) server that runs in WebAssembly (WASM) within a web browser. This project demonstrates the integration of MCP tools and resources in a browser environment.
What is WASM MCP Server?
WASM MCP Server is a Model Context Protocol (MCP) server that allows AI assistants like Claude, Cursor, and VS Code to proof-of-concept implementation of a model context protocol (mcp) server that runs in webassembly (wasm) within a web browser. this project demonstrates the integration of mcp tools and resources in a...
A proof-of-concept implementation of a Model Context Protocol (MCP) server that runs in WebAssembly (WASM) within a web browser. This project demonstrates the integration of MCP tools and resources in a browser environment.
This server falls under the Developer Tools category on MCPgee, the world's largest MCP server directory with 33,000+ servers.
Features
- A proof-of-concept implementation of a Model Context Protoco
Use Cases
Maintainer
Works with
Installation
Manual Installation
npx wasm-mcp-serverConfiguration
Configuration Details
claude_desktop_config.json
Performance
Response Metrics
Resource Usage
How to Set Up and Use WASM MCP Server
The WASM MCP Server is a proof-of-concept that demonstrates running a Model Context Protocol server entirely within WebAssembly inside a web browser. It exposes a calculator tool for arithmetic operations and a key-value storage system that persists for the browser session, proving that MCP tools and resources can operate in browser-constrained environments without a separate server process.
Prerequisites
- A modern web browser with WebAssembly support (Chrome, Firefox, Safari, Edge)
- Node.js 18 or higher for building the project
- npm or pnpm for dependency management
- Basic familiarity with WebAssembly and the MCP protocol
Clone the repository
Clone the mcp-wasm repository from GitHub to get the source code for this browser-based MCP server implementation.
git clone https://github.com/beekmarks/mcp-wasm.git
cd mcp-wasmInstall dependencies
Install all project dependencies using npm. The project uses the MCP SDK along with WebAssembly tooling to bundle the server for browser execution.
npm installBuild the WASM bundle
Compile the TypeScript MCP server to a WebAssembly-compatible bundle that can run inside a browser environment.
npm run buildLaunch the development server
Start the local development server to serve the WASM bundle and the web interface that hosts the MCP server in the browser.
npm run devOpen the browser interface
Navigate to http://localhost:3000 (or the port shown in terminal output) to access the web UI. From here you can test the calculator tool and key-value storage through the browser-embedded MCP server.
WASM MCP Server Examples
Client configuration
Since this server runs in the browser rather than as a standalone process, there is no standard claude_desktop_config.json entry. The server is accessed via its browser-hosted endpoint after starting the dev server.
{
"mcpServers": {
"wasm-mcp-server": {
"command": "npx",
"args": ["wasm-mcp-server"],
"env": {}
}
}
}Prompts to try
Example interactions with the two tools exposed by the WASM MCP server: arithmetic calculation and in-browser key-value storage.
- "Calculate 42 multiplied by 17 using the calculator tool"
- "Add 1024 and 768 and return the result"
- "Store the value 'hello world' under the key 'greeting' in storage"
- "Retrieve the value stored under key 'greeting'"
- "Divide 100 by 4 and show me the result"Troubleshooting WASM MCP Server
WebAssembly module fails to load in the browser
Ensure you are serving the files over HTTP/HTTPS rather than opening the HTML file directly from disk. WebAssembly requires a proper HTTP server context. Run npm run dev to use the included development server.
Build fails with TypeScript compilation errors
Run npm install again to ensure all dependencies including type definitions are installed. Check that your Node.js version is 18 or higher with node --version.
Storage values lost between page refreshes
This is expected behavior. The key-value storage is session-scoped and exists only in memory within the current browser tab session. Refreshing or closing the tab clears all stored values.
Frequently Asked Questions about WASM MCP Server
What is WASM MCP Server?
WASM MCP Server is a Model Context Protocol (MCP) server that proof-of-concept implementation of a model context protocol (mcp) server that runs in webassembly (wasm) within a web browser. this project demonstrates the integration of mcp tools and resources in a browser environment. It connects AI assistants to external tools and data sources through a standardized interface.
How do I install WASM MCP Server?
Follow the installation instructions on the WASM MCP Server GitHub repository. Clone the repo, install dependencies, and add the server config to your AI client.
Which AI clients work with WASM MCP Server?
WASM MCP Server works with all major MCP-compatible AI clients including Claude Desktop, Claude Code, Cursor, VS Code (GitHub Copilot), Windsurf, and Cline.
Is WASM MCP Server free to use?
Yes, WASM MCP Server is open source and available under the MIT license. You can use it freely in both personal and commercial projects.
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