ODM decisions are frequently invoked using REST.
ODM on Cloud has recently added OpenAPI support to make it simpler to invoke ODM decisions as APIs from cloud applications and processes in December 2016
OpenAPI or Swagger support also makes it easier to use with in IBM API Connect Essentials which is part of ODM Standard, Advanced in ODM V8.8.1.
This is documented in more detail in the Business Operations Connect / Decision Connect section