For Nifty or NSE charts your best choice will be globaldatafeeds.in. Take a free trial for one week or so and then decide. They cost much less than esignal. They support ninja7.

I am using zerodha's kite.trade . They do provide api's and websockets for data. They have python client and node clients too. Good alternative if you have to build your own trading platform. Or you can write your own plugins using these APIs for ninja or Amibroker.