Modern Web-based APIs: What to Expect?

Here are some quick notes for mysels on what to expect from a modern, Web-based API that facilitates data query and manipulation (and possibly remote procedure calls).

1. High-Level and Accessible: Data should be made available via an API that (1) does not require any proprietary or idiosyncratic technology, custom query language and run-time environment, and (2) imposes a particular language at the call-site. In other words, users should be able to issue queries using a standard query language over an open communication protocol on a free run-time environment, all with which they are already familiar with.
2. Liberal: Consumers should be able to issue read/write queries which may involve filtering, searching, sorting, composing and lensing without limitations, even in the existence of deeply relational data models, as long as they are authorised to read/write data of interest.
3. Performant: The evaluation performance of a query should be proportionally related to the essential complexity of the data model. Furthermore, the base performance should be good enough to allow clients to issue queries without worrying much about the performance imposed by the underlying technology, notwithstanding the need for query optimisations at the query-side in some cases.
4. Authorised: All data should be authorised at the row and column levels. Such authorisation machinery should be a built-in feature of the API to avoid a separate realm of encoding such authorisation rules. Once a query is issued and it starts being interpreted, it should be authorised without the need for a procedural intervention. Authorisation should be embedded in the query interpreter (ideally backed by relational algebra capabilities of the RDBMS) as part of the evaluation process.