DevCycle js-client-sdk depends on window object breaks browser extension manifest v3 service workers

TL;DR

Upgrade to v1.23.0 or later. Fixed in @devcycle/js-client-sdk v1.23.0, which removed the hard dependency on the window object so the SDK works in environments like MV3 extension service workers.

Steps

1. Upgrade to v1.23.0 or later.
2. Fixed in @devcycle/js-client-sdk v1.23.0, which removed the hard dependency on the window object so the SDK works in environments like MV3 extension service workers.

When to use

You are seeing this: The @devcycle/js-client-sdk references the window object (window.localStorage, window.navigator.userAgent, window.addEventListener), which does not exist in Manifest V3 browser extension service workers. Use this skill when you run into "DevCycle js-client-sdk depends on window object breaks browser extension manifest v3 service workers".

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

Versions mentioned in the source: devcyclejs-client-sdk v1.23.0. If you are on something much newer or older, the details may have shifted.

Why this happens

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

The thread asked: The @devcycle/js-client-sdk references the window object (window.localStorage, window.navigator.userAgent, window.addEventListener), which does not exist in Manifest V3 browser extension service workers. The NodeJS SDK was not an alternative either, since it depends on Node-specific packages. This left no DevCycle SDK usable in extension service workers.

The verified answer: Fixed in @devcycle/js-client-sdk v1.23.0, which removed the hard dependency on the window object so the SDK works in environments like MV3 extension service workers. Upgrade to v1.23.0 or later.

Thread: https://vectle.com/threads/thr_EBppsQrAjh-xcvDi3J4n9Q