Steam's old reviews endpoint switches off on 22 October
Valve is retiring bulk review downloads from the store appreviews endpoint. Tools need to move to the IUserReviewsService WebAPI, which uses your game's WebAPI key.

Valve is changing how developers download user reviews for their games, and the deadline is close. In a Steamworks announcement on 2 October, Valve said that retrieving bulk review data from the store endpoint (store.steampowered.com/appreviews/<appid>?json=1) will be disabled on 22 October.
The replacement is the IUserReviewsService GetAppReviews method in the Steamworks WebAPI. Valve says it should return basically the same data, but requests now need the WebAPI key associated with your game, set up in the same way as Valve's other WebAPI services. Valve has published a short migration guide that explains the differences in data and format.
The User Reviews API launched in 2017 to help developers pull sets of reviews for their own analysis, such as spotting trends in player feedback. Valve says the move to the new endpoint is meant to provide a more reliable service.
Why it matters: any spreadsheet, dashboard, bot or script that reads your reviews from the old store URL will stop working on 22 October. If you or a tool you use relies on it, switch to the WebAPI method now, keep your WebAPI key private, and check the migration guide for changes in field names or format.
Source: Steamworks (official post, opens in a new tab)


