message-port

Penpal simplifies communication with iframes, workers, and windows by using promise-based methods on top of postMessage.

Promise-based iframe communication for TypeScript. A one-time postMessage handshake hands the iframe a private MessageChannel port; then send() / reply.accept() / reply.decline() over that MessagePort, with timeouts, heartbeat and auto-reconnect. Cross-origin, zero dependencies.

A MessageChannel API