Using ManagedRuntime in Cloudflare Workers to Persist Resources Across Requests

// in my fetch handler
await Effect.runPromise(
  program.pipe(
    Effect.provide(myLayer(env)),
  )
)

import { Context, Effect, Layer, Clock, ManagedRuntime } from "effect"

class Greeter extends Context.Tag("Greeter")<
  Greeter,
  {
    greet: Effect.Effect<string>
  }
>() {}

const GreeterLive = (msg: string) => Layer.effect(
  Greeter,
  Effect.gen(function* () {
    const now = yield* Clock.currentTimeMillis
    return {
      greet: Effect.succeed(`${msg}: ${now}`)
    }
  })
)

const runtime = ManagedRuntime.make(GreeterLive("Managed Runtime"))

const program = Effect.gen(function* () {
  const greeter = yield* Greeter
  return yield* greeter.greet
})

export default {
  async fetch(request, env, ctx): Promise<Response> {
    const result = program.pipe(runtime.runSync)
    const result2 = Effect.runSync(program.pipe(Effect.provide(GreeterLive("Effect.provide"))))

    return new Response(`${result}\n${result2}`);
  },
} satisfies ExportedHandler<Env>;