# CreateAlias
<a name="API_CreateAlias"></a>

Creates an [alias](https://docs.aws.amazon.com/lambda/latest/dg/configuration-aliases.html) for a Lambda function version. Use aliases to provide clients with a function identifier that you can update to invoke a different version.

You can also map an alias to split invocation requests between two versions. Use the `RoutingConfig` parameter to specify a second version and the percentage of invocation requests that it receives.

## Request Syntax
<a name="API_CreateAlias_RequestSyntax"></a>

```
POST /2015-03-31/functions/FunctionName/aliases HTTP/1.1
Content-type: application/json

{
   "Description": "string",
   "FunctionVersion": "string",
   "Name": "string",
   "RoutingConfig": { 
      "AdditionalVersionWeights": { 
         "string" : number 
      }
   }
}
```

## URI Request Parameters
<a name="API_CreateAlias_RequestParameters"></a>

The request uses the following URI parameters.

 ** [FunctionName](#API_CreateAlias_RequestSyntax) **   <a name="lambda-CreateAlias-request-uri-FunctionName"></a>
The name or ARN of the Lambda function.  

**Name formats**
+  **Function name** - `MyFunction`.
+  **Function ARN** - `arn:aws:lambda:us-west-2:123456789012:function:MyFunction`.
+  **Partial ARN** - `123456789012:function:MyFunction`.
The length constraint applies only to the full ARN. If you specify only the function name, it is limited to 64 characters in length.  
Length Constraints: Minimum length of 1. Maximum length of 140.  
Pattern: `(arn:(aws[a-zA-Z-]*)?:lambda:)?([a-z]{2}((-gov)|(-iso([a-z]?)))?-[a-z]+-\d{1}:)?(\d{12}:)?(function:)?([a-zA-Z0-9-_]+)(:(\$LATEST|[a-zA-Z0-9-_]+))?`   
Required: Yes

## Request Body
<a name="API_CreateAlias_RequestBody"></a>

The request accepts the following data in JSON format.

 ** [Description](#API_CreateAlias_RequestSyntax) **   <a name="lambda-CreateAlias-request-Description"></a>
A description of the alias.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 256.  
Required: No

 ** [FunctionVersion](#API_CreateAlias_RequestSyntax) **   <a name="lambda-CreateAlias-request-FunctionVersion"></a>
The function version that the alias invokes.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 1024.  
Pattern: `(\$LATEST(\.PUBLISHED)?|[0-9]+)`   
Required: Yes

 ** [Name](#API_CreateAlias_RequestSyntax) **   <a name="lambda-CreateAlias-request-Name"></a>
The name of the alias.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Pattern: `(?!^[0-9]+$)([a-zA-Z0-9-_]+)`   
Required: Yes

 ** [RoutingConfig](#API_CreateAlias_RequestSyntax) **   <a name="lambda-CreateAlias-request-RoutingConfig"></a>
The [routing configuration](https://docs.aws.amazon.com/lambda/latest/dg/configuration-aliases.html#configuring-alias-routing) of the alias.  
Type: [AliasRoutingConfiguration](API_AliasRoutingConfiguration.md) object  
Required: No

## Response Syntax
<a name="API_CreateAlias_ResponseSyntax"></a>

```
HTTP/1.1 201
Content-type: application/json

{
   "AliasArn": "string",
   "Description": "string",
   "FunctionVersion": "string",
   "Name": "string",
   "RevisionId": "string",
   "RoutingConfig": { 
      "AdditionalVersionWeights": { 
         "string" : number 
      }
   }
}
```

## Response Elements
<a name="API_CreateAlias_ResponseElements"></a>

If the action is successful, the service sends back an HTTP 201 response.

The following data is returned in JSON format by the service.

 ** [AliasArn](#API_CreateAlias_ResponseSyntax) **   <a name="lambda-CreateAlias-response-AliasArn"></a>
The Amazon Resource Name (ARN) of the alias.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 10000.  
Pattern: `arn:(aws[a-zA-Z-]*)?:lambda:[a-z]{2}((-gov)|(-iso([a-z]?)))?-[a-z]+-\d{1}:\d{12}:function:[a-zA-Z0-9-_]+(:(\$LATEST|[a-zA-Z0-9-_]+))?` 

 ** [Description](#API_CreateAlias_ResponseSyntax) **   <a name="lambda-CreateAlias-response-Description"></a>
A description of the alias.  
Type: String  
Length Constraints: Minimum length of 0. Maximum length of 256.

 ** [FunctionVersion](#API_CreateAlias_ResponseSyntax) **   <a name="lambda-CreateAlias-response-FunctionVersion"></a>
The function version that the alias invokes.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 1024.  
Pattern: `(\$LATEST|[0-9]+)` 

 ** [Name](#API_CreateAlias_ResponseSyntax) **   <a name="lambda-CreateAlias-response-Name"></a>
The name of the alias.  
Type: String  
Length Constraints: Minimum length of 1. Maximum length of 128.  
Pattern: `(?!^[0-9]+$)([a-zA-Z0-9-_]+)` 

 ** [RevisionId](#API_CreateAlias_ResponseSyntax) **   <a name="lambda-CreateAlias-response-RevisionId"></a>
A unique identifier that changes when you update the alias.  
Type: String

 ** [RoutingConfig](#API_CreateAlias_ResponseSyntax) **   <a name="lambda-CreateAlias-response-RoutingConfig"></a>
The [routing configuration](https://docs.aws.amazon.com/lambda/latest/dg/lambda-traffic-shifting-using-aliases.html) of the alias.  
Type: [AliasRoutingConfiguration](API_AliasRoutingConfiguration.md) object

## Errors
<a name="API_CreateAlias_Errors"></a>

For information about the errors that are common to all actions, see [Common Error Types](CommonErrors.md).

 ** InvalidParameterValueException **   
One of the parameters in the request is not valid.    
 ** message **   
The exception message.  
 ** Type **   
The exception type.
HTTP Status Code: 400

 ** ResourceConflictException **   
The resource already exists, or another operation is in progress.    
 ** message **   
The exception message.  
 ** Type **   
The exception type.
HTTP Status Code: 409

 ** ResourceNotFoundException **   
The resource specified in the request does not exist.  
HTTP Status Code: 404

 ** ServiceException **   
The AWS Lambda service encountered an internal error.  
HTTP Status Code: 500

 ** TooManyRequestsException **   
The request throughput limit was exceeded. For more information, see [Lambda quotas](https://docs.aws.amazon.com/lambda/latest/dg/gettingstarted-limits.html#api-requests).    
 ** retryAfterSeconds **   
The number of seconds the caller should wait before retrying.
HTTP Status Code: 429

## See Also
<a name="API_CreateAlias_SeeAlso"></a>

For more information about using this API in one of the language-specific AWS SDKs, see the following:
+  [AWS Command Line Interface V2](https://docs.aws.amazon.com/goto/cli2/lambda-2015-03-31/CreateAlias) 
+  [AWS SDK for .NET V4](https://docs.aws.amazon.com/goto/DotNetSDKV4/lambda-2015-03-31/CreateAlias) 
+  [AWS SDK for C\$1\$1](https://docs.aws.amazon.com/goto/SdkForCpp/lambda-2015-03-31/CreateAlias) 
+  [AWS SDK for Go v2](https://docs.aws.amazon.com/goto/SdkForGoV2/lambda-2015-03-31/CreateAlias) 
+  [AWS SDK for Java V2](https://docs.aws.amazon.com/goto/SdkForJavaV2/lambda-2015-03-31/CreateAlias) 
+  [AWS SDK for JavaScript V3](https://docs.aws.amazon.com/goto/SdkForJavaScriptV3/lambda-2015-03-31/CreateAlias) 
+  [AWS SDK for Kotlin](https://docs.aws.amazon.com/goto/SdkForKotlin/lambda-2015-03-31/CreateAlias) 
+  [AWS SDK for PHP V3](https://docs.aws.amazon.com/goto/SdkForPHPV3/lambda-2015-03-31/CreateAlias) 
+  [AWS SDK for Python](https://docs.aws.amazon.com/goto/boto3/lambda-2015-03-31/CreateAlias) 
+  [AWS SDK for Ruby V3](https://docs.aws.amazon.com/goto/SdkForRubyV3/lambda-2015-03-31/CreateAlias)