The only way for a worker to communicate with the rest of the browser context is by using the `postMessage` method. The host code has to listen and respond via

The only way for a worker to communicate with the rest of the browser context is by using the `postMessage` method. The host code has to listen and respond via the `onmessage` handler, so the worker is unable to do anything that you don't explicitly implement in your `onmessage` handler. You still have to make sure the API you expose to the user plugins aren't exploitable.