aim_edge

Run an Aim application on Cloudflare workerd (Cloudflare Workers), compiled to WebAssembly with dart compile wasm.

import 'package:aim_edge/aim_edge.dart';

void main() {
  final app = Aim();
  app.get('/', (c) async => c.text('Hello from Dart on workerd'));
  app.serveEdge();
}

serveEdge() registers globalThis.__aimFetch. A small JS entry module instantiates the wasm module on the first request and forwards fetch(request, env, ctx) to it. See examples/edge-sample in the repository for the build script, wrangler.jsonc, and the entry module.

Bindings and request metadata

c.env returns a typed Bindings?: c.env?.string('GREETING') reads a var or secret, c.env?.get('MY_KV') returns a resource binding (KV namespace, D1 database, ...) as a raw JSObject you call with dart:js_interop, and c.env?.has('MY_KV') checks presence.

c.cf returns a typed CfProperties? for Cloudflare's request.cf metadata: c.cf?.country, c.cf?.colo, c.cf?.city, c.cf?.asn, and more.

c.executionContext is still a raw JSObject?, for waitUntil / passThroughOnException via dart:js_interop.

Middleware

The aim_server_* middleware packages (cors, cookie, form, logger, sse, jwt, basic_auth) depend on aim_core and work unchanged on workerd. aim_server_static and aim_server_multipart's saveTo() need the file system and are VM-only.

Limitations (v1)

• Request bodies are read fully into memory before the handler runs.
• Response bodies are streamed without backpressure; fast producers buffer in the JS queue.
• serveEdge() must be called synchronously from main(); the JS entry module expects globalThis.__aimFetch to exist right after invokeMain().
• Responses with status 101, 204, 205, or 304 are sent without a body regardless of the Dart body.