Simple API to get current price of coin on stellar expert

First, you need to decide how to defined the price of a coin, should it be:

• The price of the most recent trade?
• The average price of the most recent n trades?
• A volume-weighted price of the most recent X units traded?
• The midpoint between the current bid/ask?

You can get the data you need from Horizon:

• Get the most recent n trades for a coin: example
• Get the orderbook data for a coin: example