Rest.li uses a RESTSpec JSON schema as its interface definition language (IDL).
Each RESTSpec file contains the full definition of a root level resource and all its sub-resources.
RESTSpec files use the .restspec.json file extension. The contents of
each file is JSON describing the resource according to the
ResourceSchema
data schema.
For example:
The RESTSpec for the GreetingsResource implementation is com.linkedin.restli.examples.greetings.client.greetings.restspec.json