Updating Group Parameters

The MGM Membership Group Manager. May also be referred to as the Network Manager. It is a virtual node and Corda identity that acts as a central registrar for group membership. can update the current group parameters using the REST API APIs allow different software applications to communicate with each other and share data in a standardized and structured way. . Updates to the current group parameters can only include changes to the minimum platform version and custom properties. To update the group parameters, the MGM must submit an updated version of the group parameters to the REST endpoint, which overwrites any previous properties submitted using the endpoint.

To view the current group parameters use the GET method of the /api/v5_1/members/{holdingidentityshorthash}/group-parameters endpoint:

curl -k -u $REST_API_USER:$REST_API_PASSWORD -X GET $REST_API_URL/members/$HOLDING_ID/group-parameters

 Invoke-RestMethod -SkipCertificateCheck  -Headers @{Authorization=("Basic {0}" -f $AUTH_INFO)} -Uri "$REST_API_URL/membership/$HOLDING_ID/group-parameters" | ConvertTo-Json -Depth 4

To submit a group parameters update, use the POST method of the /api/v5_1/mgm/{holdingidentityshorthash}/group-parameters endpoint, as shown below. Keys of custom properties must have the prefix ext.. For the minimum platform version, use the key corda.minimum.platform.version. For example:

export GROUP_PARAMS_UPDATE='{"newGroupParameters":{"corda.minimum.platform.version": "50000", "ext.group.key.0": "value0", "ext.group.key.1": "value1"}}'
curl -k -u $REST_API_USER:$REST_API_PASSWORD -d "GROUP_PARAMS_UPDATE" $REST_API_URL/mgm/$HOLDING_ID/group-parameters

GROUP_PARAMS_UPDATE = @{
  'corda.minimum.platform.version' = "50000"
  'ext.group.key.0' = "value0"
  'ext.group.key.1' = "value1"
}
$GROUP_PARAMS_UPDATE_RESPONSE = Invoke-RestMethod -SkipCertificateCheck  -Headers @{Authorization=("Basic {0}" -f $AUTH_INFO)} -Method Post -Uri "$REST_API_URL/mgm/$HOLDING_ID/group-parameters" -Body (ConvertTo-Json -Depth 4 @{
    newGroupParameters = $GROUP_PARAMS_UPDATE
})
$GROUP_PARAMS_UPDATE_RESPONSE.parameters

These submitted parameters are combined with notary information from Corda to construct the new group parameters, which are then signed by the MGM and distributed within the network.