# Two entangled ports are a private pair

The learner can mint `new MessageChannel()`, treat delivery as twin-to-twin, and choose or reject that pair against addressing a window, a named BroadcastChannel, and a same-context function. That is now the floor: the next lesson can spend working memory on the port queue (`start` / `onmessage` / `close`) without re-teaching topology.

Evidence: the learner said they passed lesson 1 (lab both ways + checks).

Implications: teach `postMessage` (no `targetOrigin`), the disabled-until-start queue, and `close()` disentangle. Transfer and `DataCloneError` stay later.