[BUG] Asynchronous work with next/after not working

[zammitjohn]

Describe the bug

I'm currently using getCloudflareContext() to call context.waitUntil() manually for background tasks. I would like to migrate to the standardized after() API from next/server which should be supported according to docs.

When using the Cloudflare OpenNext adapter (next dev server works fine), asynchronous logic added with next/after does not consistently execute as expected. Sometimes async operations complete successfully, other times they are cut off prematurely or never awaited properly.

Steps to reproduce

import { after } from "next/server";

export const doSomethingAsync = async (input: any) => {
  // Simulate main logic
  const result = await someMainOperation(input);

  // Async follow-up task
  after(async () => {
    // This sometimes runs, sometimes doesn't
    await someAsyncSideEffect(result);
  });

  return result;
};

Expected behavior

Should reliably execute the async function after the response is returned.

@opennextjs/cloudflare version

1.9.0

Wrangler version

4.30.0

next info output

Relevant Packages:
  next: 15.4.6 // There is a newer version (15.5.4) available, upgrade recommended! 
  eslint-config-next: 15.4.6
  react: 19.1.0
  react-dom: 19.1.0
  typescript: 5.9.2

Additional context

No response

[sommeeeer]

Would you mind making a minimal reproduction? There is an E2E for it here.

[zammitjohn]

I discovered that the issue was due to a missing await in my own code. After correcting that, both waitUntil() and after() behave as expected. Apologies for the noise, and thanks for your patience!