AT Protocol

The AT Protocol is an open set of standards for decentralized publishing and distribution of self-authenticating data on the social web, and it underpins the Bluesky social network. It uses a dual identifier system of mutable domain-name handles and immutable decentralized identifiers, with user data stored in individual repositories hosted on Personal Data Servers. Relays aggregate repository updates into a network-wide stream called the firehose, which the article describes as the protocol's most centralized component, and some of its specifications are being standardized through the IETF.