Stagehand is a TypeScript library that enables type‑safe, promise‑based remote procedure calls between JavaScript execution contexts—such as Node.js child processes, web workers, or any custom message‑passing channel. It provides `launch`, `connect`, and `disconnect` utilities together with adapters that turn standard communication objects into a uniform `MessageEndpoint` interface, letting developers expose and consume objects across process boundaries with full compile‑time type checking. Intended for developers building applications that need reliable, typed inter‑process or worker communication.