I'm looking at the simplest way to monetise various API's I have. Without building from scratch things that are common across paid API's. Like whitelisting IP's, rate limiting, usage monitoring, different ways of charging/pricing models and enforcement.

For example I have a Factsheet API for Mutual Funds and ETF's, we have the most extensive repo of available factsheets. I'm unsure if Financial Institutions will switch, so simply want a framework, where by I can easily try and monetise it.

Any ideas :)