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# URLSessionWebSocketTask.CloseCode

A code that indicates why a WebSocket connection closed.

```
enum CloseCode
```

## Overview

The WebSocket close codes follow the close codes defined in [RFC 6455](https://tools.ietf.org/html/rfc6455#section-7.4.1).

## Topics

### Close codes

[`URLSessionWebSocketTask.CloseCode.abnormalClosure`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/abnormalClosure)

A reserved code that indicates the connection closed without a close control frame.

[`URLSessionWebSocketTask.CloseCode.goingAway`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/goingAway)

A code that indicates an endpoint is going away.

[`URLSessionWebSocketTask.CloseCode.internalServerError`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/internalServerError)

A code that indicates the server terminated the connection because it encountered an unexpected condition.

[`URLSessionWebSocketTask.CloseCode.invalid`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/invalid)

A code that indicates the connection is still open.

[`URLSessionWebSocketTask.CloseCode.invalidFramePayloadData`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/invalidFramePayloadData)

A code that indicates the server terminated the connection because it received data inconsistent with the message’s type.

[`URLSessionWebSocketTask.CloseCode.mandatoryExtensionMissing`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/mandatoryExtensionMissing)

A code that indicates the client terminated the connection because the server didn’t negotiate a required extension.

[`URLSessionWebSocketTask.CloseCode.messageTooBig`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/messageTooBig)

A code that indicates an endpoint is terminating the connection because it received a message too big for it to process.

[`URLSessionWebSocketTask.CloseCode.noStatusReceived`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/noStatusReceived)

A reserved code that indicates an endpoint expected a status code and didn’t receive one.

[`URLSessionWebSocketTask.CloseCode.normalClosure`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/normalClosure)

A code that indicates normal connection closure.

[`URLSessionWebSocketTask.CloseCode.policyViolation`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/policyViolation)

A code that indicates an endpoint terminated the connection because it received a message that violates its policy.

[`URLSessionWebSocketTask.CloseCode.protocolError`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/protocolError)

A code that indicates an endpoint terminated the connection due to a protocol error.

[`URLSessionWebSocketTask.CloseCode.tlsHandshakeFailure`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/tlsHandshakeFailure)

A reserved code that indicates the connection closed due to the failure to perform a TLS handshake.

[`URLSessionWebSocketTask.CloseCode.unsupportedData`](/documentation/Foundation/URLSessionWebSocketTask/CloseCode-swift.enum/unsupportedData)

A code that indicates an endpoint terminated the connection after receiving a type of data it can’t accept.


---

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