Steam Market API?

I could not find any documentation, but I use:

http://steamcommunity.com/market/priceoverview/?appid=730&currency=3&market_hash_name=StatTrak%E2%84%A2 M4A1-S | Hyper Beast (Minimal Wear)

to return a JSON. At time of writing, it returns:

{"success":true,"lowest_price":"261,35€ ","volume":"11","median_price":"269,52€ "}

You can change the currency. 1 is USD, 3 is euro but there are probably others.

A better search api that can give you all the results for a game, example using pubg which only has 272 items, if your game has more try changing the count parameter at the end

https://steamcommunity.com/market/search/render/?search_descriptions=0&sort_column=default&sort_dir=desc&appid=578080&norender=1&count=500