> ## Documentation Index
> Fetch the complete documentation index at: https://docs.rtvi.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Transport

Transports are the means by which RTVI clients communicate with the RTVI-enable bot.
They are responsible for sending and receiving messages between the client and the server as well as handling real-time media transport.

## Transport lifecycle

Your transport instance is constructed when you call `connect()` on your client instance.

```typescript
import { RTVIClient } from 'realtime-ai;
import { DailyTransport } from "@daily-co/realtime-ai-daily";

const rtviClient = new RTVIClient({
  transport: new DailyTransport(),
  ...
});

await rtviClient.connect(); // Transport instance is created here
await rtviClient.disconnect(); // Transport instance is destroyed here
```

## Transport states

`TransportState`

Your transport instance goes through a series of states during its lifecycle. These states are:

<Steps>
  <Step title="Disconnected">
    Transport is idle and has not yet been initialized (default state).
  </Step>

  <Step title="Initializing">
    Transport is being initialized. Typically in response to a
    `rtviClient.initDevices()` call, where the transport is being set up in
    order to enumerate local media devices.
  </Step>

  <Step title="Initialized">
    Transport has been initialized and is ready to connect. This state is
    typically reached after a successful `rtviClient.initDevices()` call.
  </Step>

  <Step title="Authenticating">
    Your client has called `rtviClient.connect()` and is waiting for a response
    from your server containing 'auth bundle' credentials (such as a session URL
    and token.)
  </Step>

  <Step title="Connecting">
    Transport has received the 'auth bundle' and is connecting to the server.
  </Step>

  <Step title="Connected">
    Transport has successfully connected to the session and is awaiting a
    client-ready signal (indicicated audio and video tracks are ready to be
    sent.)
  </Step>

  <Step title="Ready">Transport is ready and the session can begin.</Step>

  <Step title="Disconnecting">
    Transport is disconnecting from the session.
  </Step>

  <Step title="Error">An error occurred during the transport lifecycle.</Step>
</Steps>

You can access the current transport state via `rtviClient.state`, or by defining a callback or event:

```typescript
// Callback
const rtviClient = new RTVIClient({
  transport: new DailyTransport(),
  callbacks: {
	onTransportStateChange: (state) => {
	  console.log(state);
  }
  //...
});

// Event
rtviClient.on(RTVIEvent.TransportStateChanged, (e) => console.log(e));

// Client getter
console.log(rtviClient.state); // Disconnected <TransportState>
```