Platform Overview

Not a Meta-Framework

Most frontend libraries ship their own server runtime. Next.js has its Node server. Nuxt has Nitro. SvelteKit has its adapter system. Each one reinvents routing, request handling, middleware, and deployment — on top of what the framework already provides.

Effex doesn’t do this.

@effex/platform is a thin integration layer between Effex’s router and Effect’s HTTP platform. It doesn’t have its own server, its own request pipeline, or its own deployment story. Instead, it gives you a function — Platform.toHttpRoutes — that converts your Effex Router into an @effect/platform HttpRouter. From there, you use Effect’s existing HTTP infrastructure to serve requests however you want.

Why This Matters

Effect already has a production-grade HTTP stack:

  • HttpRouter for declarative route registration
  • HttpServerRequest / HttpServerResponse for typed request/response handling
  • HttpServer with adapters for Node, Bun, and more
  • Middleware, error handling, and observability built in
  • Full Layer-based dependency injection

Rebuilding any of this would be a waste. Instead, toHttpRoutes produces an HttpRouter that plugs into whatever Effect HTTP setup you already have:

import { HttpRouter } from "@effect/platform";
import { Platform } from "@effex/platform";

// Your Effex routes become Effect HTTP routes
const effexRoutes = Platform.toHttpRoutes(router, {
  app: App,
  document: { title: "My App", scripts: ["/client.js"] },
});

// Compose with your own API routes, middleware, etc.
const httpApp = HttpRouter.empty.pipe(
  HttpRouter.concat(apiRoutes),
  HttpRouter.concat(effexRoutes),
);

This means you can:

  • Add API routes alongside your Effex pages using the same HttpRouter
  • Use Effect middleware for auth, logging, rate limiting — things that already exist in the ecosystem
  • Deploy anywhere Effect’s HTTP platform runs — Node, Bun, Cloudflare Workers, or any custom adapter
  • Share services between your API and your page loaders via Effect’s Layer system

What @effex/platform Actually Does

The package provides three utilities:

Platform.toHttpRoutes(router, options)

Converts your Effex Router into an HttpRouter. For each route:

  • GET → runs the loader, SSR renders the page (or returns JSON for ?_data=1 client navigations)
  • POST/PUT/DELETE → dispatches to mutation handlers by ?_action=key

Platform.makeClientLayer(router)

Creates a client-side Layer for hydration. On first load, reads embedded data from the server. On subsequent navigations, fetches data via ?_data=1.

Platform.buildStaticSite(options)

Pre-renders all Route.static routes to HTML files at build time. Used by the Vite plugin for SSG.

The Vite Plugin

@effex/vite-plugin handles the dev-time and build-time integration:

  • Dev mode — SSR dev server with HMR
  • Client builds — strips server-only code (loaders, handlers) from the browser bundle
  • SSG builds — runs buildStaticSite after the SSR build

The plugin is the only piece with opinions about tooling. Everything else is just Effect.

When You Don’t Need Platform

If you’re building a pure SPA — no server rendering, no server-side data loading — you don’t need @effex/platform at all. Use Navigation.makeLayer(router) directly and run loaders client-side:

import { runApp, mount } from "@effex/dom";
import { Navigation } from "@effex/router";

runApp(
  Effect.gen(function* () {
    yield* mount(App(), document.getElementById("root")!);
  }),
  { layer: Navigation.makeLayer(router) },
);

Platform is for when you want the server involved — SSR, SSG, or server-side data loading.

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