GAIN Capital (aka OEC) have implemented a new API that will replace their existing API next month. We are supporting this in Jigsaw daytradr V 2.1.0.5 out today.
Your user id/password will be the same for the new API. There is just one thing you will need to do when yo move to this version - which is to download instruments again. With the new API, the internal instrument format is different (the Jigsaw instrument format doesn't change - it's still ESM20 for S&P for example).
If you do not download symbols - you will see an error like this:
If you see that - simply run the instrument download and the internal tables will be updated.
In June, we expect that GAIN will disable the old API, at that point versions prior to 2.1.0.5 will no longer connect to the API.