HTTP GET请求在正常会话上有效，但在“隐身”会话中无效

Question

Having some trouble understanding why this issue is happening, specifically within the Steam environment.

When I go to this URL and am logged in to Steam, the request goes through fine and I get the return that I'm expecting. However, when I try the request in an incognito session, I get an empty set of results. I've looked through the code that Steam itself uses to send this request (ctrl-f '// Load' and it should bring you to the relevant code). There doesn't seem to be any identifying information being passed in this request, and even in incognito mode Steam will still load up the price history charts for the item just fine. I can't understand why the request will not work in a session in which the user isn't logged in to Steam even though the page itself will still display price history using the same request.

Answer 1

Since this occurs on Valve's servers, this is simply an educated guess as to what is occurring.

When you visit this URL without being logged in, the server is sending back a 400 Bad Request

It appears this is due to the lack of a steamLogin cookie. When you visit the URL without being logged in, these cookies are set

timezoneOffset
Steam_Language
community_game_list_scroll_size
recentlyVisitedAppHubs
sessionid
steamCC_<IP_OF_COMPUTER>

After logging in, when the request is successful, the steamLogin cookie also exists.

It appears you need this cookie to get the information you want.

Answer 2

Can't comment (rep too low) but FYI, the item detail page works because the data for the graph is passed inside the html file in a bracket. You could set up a DOM environment, load the html and scrape it out without needing to login.

As the other poster mentioned, the api call you want to use requires the steamLogin cookie to work.