Install

npm i @expressots/adapter-express

What This Package Does

This adapter bridges ExpressoTS Core and Express.js. It provides the HTTP server implementation, route registration, middleware pipeline, and the App class that wires everything together. Install it alongside @expressots/core to run ExpressoTS on Express.

Quick Look

import { AppExpress } from "@expressots/adapter-express";
import { AppContainer, CreateModule, bootstrap } from "@expressots/core";
import { AppController } from "./app.controller";

export class App extends AppExpress {
  private readonly container: AppContainer = this.configContainer([CreateModule([AppController])]);

  async configureServices(): Promise<void> {
    // register middleware, interceptors, error handlers
  }
}

void bootstrap(App); // starts on process.env.PORT or 3000

bootstrap() builds the container, runs the AppExpress lifecycle hooks (globalConfiguration, configureServices, postServerInitialization), starts the HTTP server, and wires graceful shutdown on SIGINT / SIGTERM.

Requirements

• Express 5 (the adapter targets the Express 5 API; body parsing uses the Express 5 native parsers)
• Node.js >= 20.19.0
• @expressots/studio-agent is an optional peer dependency: install it to enable ExpressoTS Studio integration, or omit it with no impact on the adapter.

Preview modules

The micro-api module (gateway, service-mesh, serverless, queue) is preview quality: its APIs may change. Use it for experimentation, not production-critical paths.

Cloudflare binding providers

On Cloudflare Workers, a micro app can resolve its bindings (KV, D1, R2, Queues) through typed tokens instead of reading env by name in every handler:

import {
  cloudflareAdapter,
  cloudflareBindings,
  type CloudflareRequest,
  micro,
} from "@expressots/adapter-express";

interface Env {
  SETTINGS: KVNamespace;
  DB: D1Database;
}

const bindings = cloudflareBindings<Env>();
const Settings = bindings.kv("SETTINGS");
const Database = bindings.d1("DB");

const app = micro<CloudflareRequest<Env>>({ showBanner: false, studio: { enabled: false } });

app.get("/theme", async (req) => ({
  theme: await req.services.get(Settings).get("theme"),
}));

app.get("/items", (req) => req.services.get(Database).prepare("SELECT * FROM items").all());

export default cloudflareAdapter<Env>(app);

• bindings.kv, bindings.d1, bindings.r2 and bindings.queue return frozen tokens, memoized by kind and name. Tokens carry only a name and a kind, so creating them at module scope is safe on Workers.
• req.services.get(token) reads the binding from the current request's env every time; nothing is cached across requests. req.services.has(token) reports whether the binding is present. req.cloudflare.env remains available for direct access.
• A binding absent from env raises CloudflareBindingNotFoundError (code: "EXPRESSOTS_CLOUDFLARE_BINDING_NOT_FOUND"), which flows through the app's error handler like any other error. Inherited object properties such as toString are never treated as bindings.
• Binding kinds are matched structurally against Cloudflare's runtime interfaces (for example, a KV namespace is recognised by getWithMetadata). With an explicit Env, each factory accepts only the names whose value matches its kind, and a value matching more than one kind is rejected as ambiguous. Without an Env type, any string is accepted, for applications whose bindings are configured dynamically.

The providers are verified inside workerd against Miniflare's KV, D1, R2 and Queue implementations, and a bundle gate keeps their cost under 1 KiB gzip; both run in CI from test/cloudflare-bindings-worker.

Documentation

For guides, API reference, architecture patterns, and examples visit doc.expresso-ts.com.

Contributing

Welcome to the ExpressoTS community. See the Contributing Guide for how to get involved.

Support the project

• GitHub Sponsors
• Star the organization on GitHub
• Discord
• Report an issue

License

MIT. See LICENSE.