# Bluesky and the AT Protocol: Usable Decentralized Social Media

arXiv: https://arxiv.org/abs/2402.03239 · HTML: https://mlsanity.com/paper/2402.03239/

## Key facts

- Cited by 9 papers in the map (data through 14 Oct 2026).
- First posted on arXiv 5 Feb 2024.

## Built on by (most cited first, 9 of 9)

- [FEDSTR: Money-In AI-Out | A Decentralized Marketplace for Federated Learning and LLM Training on the NOSTR Protocol](https://mlsanity.com/paper/2404.15834/) (2024)
- [PolitiSky24: U.S. Political Bluesky Dataset with User Stance Labels](https://mlsanity.com/paper/2506.07606/) (2025)
- [CognitiveSky: Scalable Sentiment and Narrative Analysis for Decentralized Social Media](https://mlsanity.com/paper/2509.11444/) (2025)
- [Can Foundation Models Moderate Online Content? Evaluating Instruction- vs. Example-Driven Policy Operationalization](https://mlsanity.com/paper/2609.10410/) (2026)
- [A Case for Specialisation in Non-Human Entities](https://mlsanity.com/paper/2503.04742/) (2025)
- [Are Open-Weight LLMs Ready for Social Media Moderation? A Comparative Study on Bluesky](https://mlsanity.com/paper/2602.05189/) (2026)
- [Algorithmic Cultivation: How Social Media Feeds Shape User Language](https://mlsanity.com/paper/2605.17010/) (2026)
- [Characterizing Bluesky Content Moderation Service: From Automation of Service to Landscape of Harms](https://mlsanity.com/paper/2609.11373/) (2026)
- [Building Trustworthy Mental Health Benchmarks on Bluesky: A Validation-Aware Weak-Supervision Framework](https://mlsanity.com/paper/2609.22696/) (2026)

## Abstract (arXiv)

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.