Looking for a data provider with API access

Mar 8, 2008
I'm looking for a company that provides data on the stock market. It doesn't matter which stock market, it could be the LSE, NYSE, NASDAQ etc etc I really don't care.

It also does not need to be real time but I need to be able to get data at regular intervals throughout the day say every 10 to 20 minutes and I absolutely must be able to access this data through an API which is compatible with the C# programming language (so either a REST API or a native C# library).

Pulling data into Excel 2016 wouldn't hurt either. I've looked around but I can't really find what I am looking for. I'm not a professional trader, I'm just a programmer with an idea I'd like to experiment on with some data and if my idea works I'd then like to move on to making some trades but for the time being I just want to validate my idea with some real world data.

If anyone can point me in the right direction I would be very grateful :).