In an attempt to make the Orion REST API easier to work with, I have posted Swagger/OpenAPI spec files (swagger.json, openapi.json). These can be used to generate client wrappers using tools like Swagger Codegen and Microsoft AutoRest. These spec files are based on the SWIS APIs available in the latest Orion product releases as of December 2018. This means Orion Platform 2018.4, NPM 12.4, NCM 7.9, etc.
OpenAPI spec files can also be used to generate interactive documentation . This is available at https://solarwinds.github.io/OrionSDK/swagger-ui/.
Orion Platform 2018.4 contains an addition to the format of the REST API. Prior to this release, verb arguments had to be passed as JSON arrays - positional arguments. This is still supported. Starting in this release, verb arguments will also be accepted in JSON object format - named arguments. I expect this to be more usable overall, but the immediate motivation for it is that the OpenAPI schema model does not provide a way to describe an array where each element is of a specific, possibly different, type.
Feedback on this new API documentation method is welcome; I hope to refine it in future releases.