Shared model objects across integration response models in apigateway - amazon-web-services

Question

Say I have 2 response models A and B. A and B shared a common nested object C. (ie A.C.field1 B.C.field1).
As I understand APIGateway today I must define C in the model definition for A and then again for B.
This results in two undesirable outcomes:
Totally duplicated json schema (annoying but not impossible to manage).
In the generated obj-c (or java) SDK I have two distinct classes A.C and B.C. This duplication complicates use of the SDK as the two version of C are not the same type.

Answer 1

You can define your shared model object and refer to it in other models with a canonical reference.
Assuming you've defined a common model "C", you could refer to model "C" in models A or B with the following JSON schema:
Model A or B:
{
"$schema": "http://json-schema.org/draft-04/schema#",
"type": "object",
"properties": {
"field": {
"$ref": "https://apigateway.amazonaws.com/restapis/{{api-id}}/models/C"
}
}
}
The generated SDKs will have a common object C.
If your shared object properties are contained to a single Model, you can use an inline reference instead:
{
"$schema": "http://json-schema.org/draft-04/schema#",
"definitions": {
"C": {
"type": "object",
"properties": {
...
}
}
},
"type": "object",
"properties": {
"field": { "$ref": "#/definitions/C" },
...
}
}