# ConnectAsMaster
<a name="ConnectAsMaster"></a>

Connects as a master to the signaling channel specified by the endpoint. Any WebSocket-complaint library can be used to connect to the secure websocket (WSS) endpoint obtained from a `GetSignalingChannelEndpoint` API call. The Amazon Resource Name (ARN) of the signaling channel must be provided as a query string parameter. There are separate endpoints for connecting as a master and as a viewer. If more than one client connects as master to a specific channel, then the most recent request takes precedence. Existing connection metadata is overwritten by the new one.

## Request
<a name="ConnectAsMaster-request"></a>

```
"X-Amz-ChannelARN": "string"
```
+ **X-Amz-ChannelARN** - ARN of the signaling channel.
  + Type: string
  + Length constraints: Minimum length of 1. Maximum length of 1024.
  + Pattern: `arn:aws:kinesisvideo:[a-z0-9-]+:[0-9]+:[a-z]+/[a-zA-Z0-9_.-]+/[0-9]+`
  + Required: Yes

## Response
<a name="ConnectAsMaster-response"></a>

200 OK HTTP status code with an empty body.

## Errors
<a name="ConnectAsMaster-errors"></a>
+ InvalidArgumentException

  A specified parameter exceeds its restrictions, is not supported, or cannot be used. For more information, see the returned message.

  HTTP Status Code: 400
+ AccessDeniedException

  The caller is not authorized to access the given channel or the token has expired.

  HTTP Status Code: 403
+ ResourceNotFoundException

  The channel doesn't exist.

  HTTP Status Code: 404
+ ClientLimitExceededException

  When the API is invoked at a rate that is too high. For more information, see [Amazon Kinesis Video Streams with WebRTC service quotas](kvswebrtc-limits.md) and [Error Retries and Exponential Backoff in AWS](https://docs.aws.amazon.com/general/latest/gr/api-retries.html).

  HTTP Status Code: 400

## Limits/Throttling
<a name="ConnectAsMaster-limits"></a>

This API is throttled at an account level if the API is invoked at too high a rate. An error returned when throttled with `ClientLimitExceededException`.

## Idempotent
<a name="ConnectAsMaster-idempotent"></a>

If a connection already exists for the specified clientId and channel, the connection metadata is updated with the new information.

## Retry behavior
<a name="ConnectAsMaster-retry"></a>

This is counted as a new API call.

## Concurrent calls
<a name="ConnectAsMaster-concurrent"></a>

Concurrent calls are allowed, the connection metadata is updated for each call.