December 15, 2024 @ 04:35 Information primarily from the [Perplexity prompt](https://www.perplexity.ai/search/explain-bluesky-s-at-protocol-ulWyokloT_ap3vcvWvcDdA): - "Explain Bluesky's AT Protocol" # The AT Protocol The Authenticated Transfer (AT) Protocol is an open-source, decentralized social networking protocol that was developed at Bluesky to address the shortcomings of both existing centralized and decetralized social media platforms. The goal of the AT Protocol is to create a standard for social networking that is open, interoperable, and scalable. Bluesky serves as the its proof of concept. The protocol employees a federated model, which allows multiple servers to communicate with one another, and allows users to both choose their own service providers and self-host their accounts if they wish. > A federated model is an approach to integrating and managing multiple independent components or systems while allowing them to maintain a degree of autonomy ([Perplexity](https://www.perplexity.ai/search/explain-bluesky-s-at-protocol-ulWyokloT_ap3vcvWvcDdA#1)) For user authentication, the AT Protocol uses a dual-identifier system that checks: 1. A mutable domain handle (such as @justcallmeSparks.bsky.social) 2. An immutable decentralized indentifier (IDI) Such a setup allows users to maintain identity across multiple systems and platforms while retaining the freedom of service provider selection. User freedom and control over data is top priority for the protocol. User data is kept separate from application functionality, and user data is openly accessible and extremely portable, so it can be taken from platform to platform without fear of losing it forever if Bluesky were to cease to exist. While Twitter made its API increasingly difficult to access (througn prohibitive pricing and other means) before shutting off access entirely--right before the fucking election--Bluesky has allowed open access to its source code (duh, it's open source) and its API allows "firehosing" of the site data and realtime activity, and much more. This opens the door for developers to do all kinds of thinds with the site, prevents a singular person, group, or company from gaining a stranglehood on the site (someone could just branch it and start another Bluesky), and provides users with yet another way to interface with and use their data.