Provide Access to Certain tables and Views via webAPI

Have you read the Appian documentation on the Web API object?  It should give you a good start into what you're asking for since it directly supports your use case as far as I can tell.

Thanks Mike. I did read the docs. Probably I should have been little more clear in my question. Certainly I can put API endpoint URL on top of CDT. So normally in Appian world do we create multiple endpoint URL for each CDT? Can we add multiple CDTs in single API endpoint ?

I think you have various different ways to do it, since APIs potentially accept different parameters on top of the given endpoint - in this sense you could build your expression within your API to return any of a variety of different things depending on certain input parameters, if you choose. 

I think though that the most common use case for Web APIs is to build a different API and endpoint for each different data type/table you'd like to allow to be queried.  I'd suggest you experiment with different approaches and see what best fits with the specifics of your use case(s).

I think you have various different ways to do it, since APIs potentially accept different parameters on top of the given endpoint - in this sense you could build your expression within your API to return any of a variety of different things depending on certain input parameters, if you choose. 

I think though that the most common use case for Web APIs is to build a different API and endpoint for each different data type/table you'd like to allow to be queried.  I'd suggest you experiment with different approaches and see what best fits with the specifics of your use case(s).