The Gaia Online Game System Interface (GSI) is an internal, public-facing HTTP API. Its primary use is for the support for games on Gaia Online. It is also a general-use API for other various systems such as market and user data etc. There is no OAuth, or authentication of any kind, apart from some methods that require you to be authenticated on Gaia Online, or to pass a session when prompted.
https://www.gaiaonline.com/chat/gsi
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