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).

# /greengrass/groups/GroupId/certificateauthorities/CertificateAuthorityId


## GET


 `GET /greengrass/groups/GroupId/certificateauthorities/CertificateAuthorityId`

Operation ID: [GetGroupCertificateAuthority](getgroupcertificateauthority-get.md)

Retreives the CA associated with a group. Returns the public key of the CA.

Produces: application/json

### Path Parameters


[**GroupId**](parameters-groupidparam.md)  
The ID of the Greengrass group.  
where used: path; required: true  
type: string

[**CertificateAuthorityId**](parameters-certificateauthorityidparam.md)  
The ID of the certificate authority.  
where used: path; required: true  
type: string

### CLI


```
aws greengrass get-group-certificate-authority \
  --group-id <value> \
  --certificate-authority-id <value>  \
  [--cli-input-json <value>] \
  [--generate-cli-skeleton]
```

cli-input-json format:

```
{
"GroupId": "string",
"CertificateAuthorityId": "string"
}
```

### Responses


**200**  
Success. The response body contains the PKI configuration.  
 [ GetGroupCertificateAuthorityResponse](definitions-getgroupcertificateauthorityresponse.md)   

```
{
"PemEncodedCertificate": "string",
"GroupCertificateAuthorityArn": "string",
"GroupCertificateAuthorityId": "string"
}
```  
GetGroupCertificateAuthorityResponse  
Information about a certificate authority for a group.  
type: object  
PemEncodedCertificate  
The PEM encoded certificate for the group.  
type: string  
GroupCertificateAuthorityArn  
The ARN of the certificate authority for the group.  
type: string  
GroupCertificateAuthorityId  
The ID of the certificate authority for the group.  
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

**500**  
Server error.  
 [ 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