# Getting Started

Install the package. It's only \~1.9kb at the time of writing.

```
npm i hypercast
```

### Topics

Hypercast instances have many *topics,* which are kind of like a channel that a group of Hypercast clients connect to and communicate through. So to use Hypercast, you need to create and manage one or more topics.

The easiest way to do this is with the `Operator` class:

```typescript
import { Operator } from 'hypercast/client'

const operator = new Operator()
const { topic } = await operator.createTopic()
```

Once you have a topic, you can instantiate a Hypercast client.

```typescript
const hypercast = operator.connect(topic)
```

Other times, you'll have the topic already and can stand up a client directly.

```typescript
import { Hypercast } from 'hypercast/client'

const hypercast = new Hypercast(topic)
```

### Sending Messages

With your Hypercast client you can now send and receive messages from other clients connected to the same topic. Clients don't receive messages their own messages, only those that originated from other connections.

```typescript
hypercast.on('message', ({ data }) => {
  console.log('received', data)
})

hypercast.send('hello')
```

You can send any serializable message you wish. Arrays, objects, numbers, and strings are all fair game. The client instance will internally stringify what you pass it, so no need to run `JSON.stringify` unless you have non-standard stuff like circular references.

```typescript
hypercast.send({ message: 'hello' })
```

### Full(ish) example

```typescript
import { Operator } from 'hypercast/client'

enum Event {
  Connect = 'connect',
  Message = 'message',
}

type Events = {
  type: Event.Connect
  data: { name: string },
} | {
  type: Event.Message,
  data: { value: string },
}

const operator = new Operator<Events>('...')
const { topic } = await operator.createTopic()
const hypercast = operator.connect(topic)

hypercast.on('message', ({ type, data }) => {
  switch (type) {
    case Event.Connect:
      setName(data.name)
      break
    case Event.Message:
      setMessages(state => [...state, data.value])
  }
})

const ack = hypercast.send({
  type: Event.Connect,
  data: { name: 'Jane' },
})

await ack
```