Bluesky’s mission is to drive the evolution from platforms to protocols. The conceptual framework we've adopted for meeting this objective is the "self-authenticating protocol."
AT Protocol
The AT Protocol is a protocol and set of open standards for decentralized publishing and distribution of self-authenticating data within the social web. It serves as the technical foundation of the Bluesky social network, originally developed as a reference implementation for the protocol, as well as an ecosystem of interoperable social applications and services collectively referred to as the ATmosphere.
Bryan Newbold: Protocol engineering
A protocol engineer at the social-media platform Bluesky describes building an open protocol around a fast-growing social media platform.
Beyond Bluesky: These are the apps building social experiences on the AT Protocol | TechCrunch
A list of AT Protocol-based, consumer-facing apps that are either built on top of Bluesky or its underlying protocol, allowing users to take back control over their social networking experiences and personal data.
Predicting Bluesky’s Scale with Jaz
Bluesky has been on a roller coaster of growth for over a year. From the early days of figuring out a new distributed social protocol—AT protocol—to actually buildi…
Proposal: OAuth Scopes · bluesky-social atproto · Discussion #3655
Note: a more complete proposal was published in July 2025: https://github.com/bluesky-social/proposals/tree/main/0011-auth-scopes We’re continuing work on rolling OAuth out to the atproto network. ...
Bluesky and the AT Protocol: Usable Decentralized Social Media
Bluesky is a new social network built upon the AT Protocol, a decentralized foundation for public social media. It was launched in private beta in February 2023, and has grown to over 10 million registered users by October 2024. In this paper we introduce the architecture of Bluesky and the AT Protocol, and explain how the technical design of Bluesky is informed by our goals: to enable decentralization by having multiple interoperable providers for every part of the system; to make it easy for users to switch providers; to give users agency over the content they see; and to provide a simple user experience that does not burden users with complexity arising from the system's decentralized nature. The system's openness allows anybody to contribute to content moderation and community management, and we invite the research community to use Bluesky as a dataset and testing ground for new approaches in social media moderation.
Weblog.social | AT Protocol Bridge
To connect securely, you must generate a dedicated Application Password via Bluesky.
Bluesky Protocol Services
High scale open social, unlocked for every builder. Bluesky operates public infrastructure for the AT Protocol — Jetstream, Relay, and the Bluesky API — as open services anyone can build on.
Progress on Auth Scopes Implementation (August 2025) · bluesky-social atproto · Discussion #4118
Since our last update on Auth Scopes, the Bluesky team has been hard at work adding support to our reference PDS implementation. Aspects of this work are starting to roll out in the production netw...
OAuth Client Security in the Atmosphere · bluesky-social atproto · Discussion #3950
The following was written by the Bluesky team as an overview of OAuth client security considerations, especially for client app developers or readers of the ATProto OAuth profile specification. Set...
How It Works | Bluesky Protocol Services
From one post to the whole network — how records, Lexicons, and the firehose fit together on the AT Protocol.
The AT Protocol | Bluesky
The AT Protocol (Authenticated Transfer Protocol, or atproto) is a standard for public conversation and an open-source framework for building social apps.
The AT Protocol's interesting design - LittleBit
Bluesky's backend was made to be more than a social network
