Use a GUID from once schema in another schema via API

Hi,

Is it possible to use GUID from one schema in another when using the API?

Example:

**schema1_guid**: e79c7d16-6603-4146-980a-07173ba45224
key: value
schema2: {
      schema2_guid: 95ed2886-5e37-47b8-921e-b5522deda671
      key: value
      **schema1_guid**: e79c7d16-6603-4146-980a-07173ba45224
}

Any help would be greatly appreciated.

Thanks