Intro

There are multiple APIs for itch.io, depending on your use case, you might want to use one or multiple at the same time.

All the APIs are listed in the sidebar, some have their own quirks, to read about them, click on the API name.

All the JSON APIs have a quirk caused by the library that was used to serialize objects by the server. Where normally you'd find an empty array [ ], the library will return an empty object { }. This quirk still exists for backwards compatibility reasons, it might not exist in newer versions of the API.
See itch.io#1301 and go-itchio@b3ae624

Glossary

Endpoints

A base URL is the url that needs to be prepended to the method path, you can find it in the main page for the API you want to use, if not specified, use https://itch.io.
Parts of the URL in {name} format are URL parameters, they are replced with the value of the parameter, including the {}, e.g. /games/{gameId}/ => /games/5318008/.
All other parameters are query parameters, following HTTP standards.
The HTTP method for requests is defined in the endpoint page header.

Types

If a class extends another class, it has all the properties of the parent, plus ones defined bellow.
Arrays types have [] appended to the base type, e.g. string[] is an array of string.
Numeric types have their bitness appended to them, e.g. int32 is a 32 bit integer.
DateTime represents a struct containing a date and time.

Base response

Most APIs here will return the following JSON object on a non 2xx error code:

Field	Type	Description
errors	string[]	List of errors that have occured. If not set, no errors
details	string	A more detailed error.