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

Local serverstdioTypeScript

What is the WASM MCP server?

Most file and storage access work still happens through a UI a human drives. WASM MCP server moves it into the conversation instead. 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.

The tools it exposes

The server publishes 3 tools. What each one is for:

  • Architecture — The Architecture tool exposed by this server
  • Calculator — 1. Select an operation (add, subtract, multiply, divide) 2. Enter two numbers 3. Click "Calculate" to see the result 4. Error handling for invalid
  • Storage — 1. Enter a key and value in the respective fields 2. Click "Set Storage" to store the value 3. Enter a key and click "Get Storage" to retrieve a

Getting it running

Setup follows the usual MCP pattern — install or clone the server, register it in your client's configuration file, restart the client.

How it compares

Among the file and storage access options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. WASM's toolset — Architecture, Calculator, Storage — is a fair guide to whether it matches your workflow. It is maintained by beekmarks; worth a glance at recent repository activity before you build anything load-bearing on it.

This entry was verified against WASM's own documentation before publication; SyncDev keeps the directory reviewed rather than auto-generated.

Things to watch

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • Keep per-call confirmation enabled while you learn its behaviour; it is the cheapest safeguard you have.

Available tools

ToolWhat it does
ArchitectureThe Architecture tool exposed by this server.
Calculator1. Select an operation (add, subtract, multiply, divide) 2. Enter two numbers 3. Click "Calculate" to see the result 4. Error handling for invalid inputs and division by zero
Storage1. Enter a key and value in the respective fields 2. Click "Set Storage" to store the value 3. Enter a key and click "Get Storage" to retrieve a value 4. Feedback provided for successful operations and errors

Example prompts to try

  • Use WASM to Architecture.
  • Use WASM to Calculator.
  • Use WASM to Storage.

Frequently asked questions

It is a proof-of-concept to show the feasibility of running an MCP server in a web browser using WebAssembly, focusing on core MCP concepts like tools and resources.