Does anyone has any experience with developing applications using Fix Api protocol (using the FIX 4.4 protocol) to trade Forex via this ?
I would like to know how and when to start ? Where can I get test environment ? Where can I get some examples of writing code/using it with Forex brokers ?
For a start, try using the Quickfix library, either in Java or C++. There are others too, but I have used this library and it is quite extensively used in the financial industry.
It has a well documented API help and there is a lot of help on this library available. You can use two instances of this library as a test environment to test. Forex brokers would not share their code with anybody else, nobody wants to go to jail. All you can get is maybe sample market data from one of the market data providers i.e. Bloomberg, Reuters etc