keystone/api-ref/source/v3-ext/federation/assertion/samples/ecp-saml-assertion-request.json

{
    "auth": {
        "identity": {
            "methods": [
                "token"
            ],
            "token": {
                "id": "--token_id--"
            }
        },
        "scope": {
            "service_provider": {
                "id": "--sp_id--"
            }
        }
    }
}