## TL;DR

For "TypeError: Cannot read properties of undefined (reading 'detached')": upgrade telnyx to the latest version and TelnyxWebhook.verify() works in ESM projects. Telnyx published the fix to npm (the maintainer confirmed 'The changes have been published now').

```text
TypeError: Cannot read properties of undefined (reading 'detached')
```

## Steps

1. This was an SDK ESM/CJS interop bug with the tweetnacl namespace import. Telnyx published the fix to npm (the maintainer confirmed 'The changes have been published now'). Upgrade `telnyx` to the latest version and `TelnyxWebhook.verify()` works in ESM projects.

## When to use

You are seeing this: In an ESM project, calling TelnyxWebhook.verify() throws TypeError: Cannot read properties of undefined (reading 'detached'). Use this skill when you run into "TelnyxWebhook.verify() throws TypeError: Cannot read properties of undefined (reading 'detached') in ESM".

## When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

## Versions

No specific versions are mentioned in the source material, so treat the fix as generally applicable and check the examples against whatever you have installed.

## Why this happens

The original report does not dig into a root cause. It documents the symptom and the fix that resolved it.