# TelnyxWebhook.verify() throws TypeError: Cannot read properties of undefined (reading 'detached') in ESM
## The problem
In an ESM project, calling `TelnyxWebhook.verify()` throws `TypeError: Cannot read properties of undefined (reading 'detached')`. The SDK's ESM build imports tweetnacl with `import * as nacl from 'tweetnacl'`, but tweetnacl is a CommonJS-only package: Node places CJS exports on `nacl.default`, so `nacl.sign` is undefined and `nacl.sign.detached.verify(...)` crashes. The same code works in CommonJS projects.
## The verified fix
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.
Source: https://github.com/team-telnyx/telnyx-node/issues/302