I used Ember.js to make an MCP server

https://mcp.decile.com is an MCP Server I built that uses Ember.js!

Okay, perhaps I overstated that a bit. The MCP server was built using a whole bunch of stuff for the backend, frontend, and infrastructure from Kubernetes to Starlette to Django REST Framework to nginx to ... you name it. Ember.js only powers the MCP Apps that are embedded by the MCP Server (about 5 of them so far). Unsurprisingly, ember was well suited to this problem (although not perfect).

What went well?

• The "gjs" file format is very pleasant for human authoring and AI did a great job of working with it. I suspect that this is because it uses strict imports for everything so the AI (or human) don't have to rely on implicit context in order to reason about what a component does.
• The new build system based on Vite was lightning fast and flexible! I was able to make the customizations I needed to execute in an MCP App context pretty easily.
• Using a monorepo with shared components importable by any of the MCP Apps and tree-shaken away if not used was very convenient! Sharing the boilerplate lint config files, vite configs, etc., as importable ".mjs" files to avoid copying those across each separate mcp-app (and full ember app).
• Using an Ember.js service to abstract away the mcp-apps SDK into a more reactive, "ember native" API was really easy and makes testing trivial.

'use strict';

module.exports = function (environment) {
  const modulePrefix = 'view-audience';
  const ENV = {
    modulePrefix,
    environment,
    rootURL: '/',
    locationType: 'hash',
    EmberENV: {
      EXTEND_PROTOTYPES: false,
      FEATURES: {},
    },
    APP: {
      MCP_SERVER_BASE_URL: '__MCP_SERVER_BASE_URL__',
    },
    'mcp-app': {
      appInfo: {
        name: modulePrefix,
        title: 'View Audience',
        version: '1.0.0',
      },
      capabilities: { availableDisplayModes: ['inline', 'fullscreen'] },
    },
  };

  ...

  return ENV;
};

What didn't go so well?

• Originally, I planned on using the new renderComponent( helper that allows rendering an individual component instead of a full app with router, service injections, etc., but I quickly started to miss the things the app provided.
• The bundle size is larger than desired, but much of that is actually the MCP Apps SDK, which bundles every locale of zod.

There's a lot more to speak to but I'm out of time (it's 9 AM now)!