Manual

Rx.manual lets you create a reactive from scratch.

Create it and provide some options to handle key states:

const rx = Rx.manual({
  onDispose(reason) {
    // Called when stream is disposed
  },
  onFirstSubscribe() {
    // Called when we go from no subscribers to at least one
  },
  onNoSubscribers() {
    // Called when all subscribers are removed
  }
})

And then you can use .set() to set values and read it as usual.