End of support notice: On October 7th, 2026, AWS will discontinue support for AWS IoT Greengrass Version 1. After October 7th, 2026, you will no longer be able to access the AWS IoT Greengrass V1 resources. For more information, please visit [Migrate from AWS IoT Greengrass Version 1](https://docs.aws.amazon.com/greengrass/v2/developerguide/migrate-from-v1.html).

# GetCoreDefinitionVersion


Retrieves information about a core definition version.

URI: `GET /greengrass/definition/cores/CoreDefinitionId/versions/CoreDefinitionVersionId`

Produces: application/json

## CLI:


```
aws greengrass get-core-definition-version \
  --core-definition-id <value> \
  --core-definition-version-id <value>  \
  [--cli-input-json <value>] \
  [--generate-cli-skeleton]
```

cli-input-json format:

```
{
"CoreDefinitionId": "string",
"CoreDefinitionVersionId": "string"
}
```

## Parameters:


[**CoreDefinitionId**](parameters-coredefinitionidparam.md)  
The ID of the core definition.  
where used: path; required: true  
type: string

[**CoreDefinitionVersionId**](parameters-coredefinitionversionidparam.md)  
The ID of the core definition version. This value maps to the `Version` property of the corresponding `VersionInformation` object, which is returned by `ListCoreDefinitionVersions` requests. If the version is the last one that was associated with a core definition, the value also maps to the `LatestVersion` property of the corresponding `DefinitionInformation` object.   
where used: path; required: true  
type: string

## Responses:


**200**  
Success.  
 [ GetCoreDefinitionVersionResponse](definitions-getcoredefinitionversionresponse.md)   

```
{
"Arn": "string",
"Id": "string",
"Version": "string",
"CreationTimestamp": "string",
"Definition": {
  "Cores": [
    {
      "Id": "string",
      "ThingArn": "string",
      "CertificateArn": "string",
      "SyncShadow": true
    }
  ]
},
"NextToken": "string"
}
```  
GetCoreDefinitionVersionResponse  
type: object  
Arn  
The ARN of the core definition version.  
type: string  
Id  
The ID of the core definition version.  
type: string  
Version  
The version of the core definition version.  
type: string  
CreationTimestamp  
The time, in milliseconds since the epoch, when the core definition version was created.  
type: string  
Definition  
Information about a core definition version.  
type: object  
Cores  
A list of cores in the core definition version.  
type: array  
items: [Core](definitions-core.md)  
Core  
Information about a core.  
type: object  
required: ["Id", "ThingArn", "CertificateArn"]  
Id  
A descriptive or arbitrary ID for the core. This value must be unique within the core definition version. Maximum length is 128 characters with the pattern `[a‑zA‑Z0‑9:_‑]+`.  
type: string  
ThingArn  
The ARN of the thing that is the core.  
type: string  
CertificateArn  
The ARN of the certificate associated with the core.  
type: string  
SyncShadow  
If true, the core's local shadow is synced with the cloud automatically.  
type: boolean  
NextToken  
The token for the next set of results, or `null` if there are no more results.  
type: string

**400**  
Invalid request.  
 [ GeneralError](definitions-generalerror.md)   

```
{
"Message": "string",
"ErrorDetails": [
  {
    "DetailedErrorCode": "string",
    "DetailedErrorMessage": "string"
  }
]
}
```  
GeneralError  
General error information.  
type: object  
required: ["Message"]  
Message  
A message that contains information about the error.  
type: string  
ErrorDetails  
A list of error details.  
type: array  
items: [ErrorDetail](definitions-errordetail.md)  
ErrorDetail  
Details about the error.  
type: object  
DetailedErrorCode  
A detailed error code.  
type: string  
DetailedErrorMessage  
A detailed error message.  
type: string