Rethinking Social Media: Bluesky and the AT Protocol’s Approach to Moderation and User Control

Table of Links

Abstract and 1 Introduction

2 The Bluesky Social App

2.1 Moderation Features

2.2 User Handles

2.3 Custom Feeds and Algorithmic Choice

3 The at Protocol Architecture

3.1 User Data Repositories

3.2 Personal Data Servers (PDS)

3.3 Indexing Infrastructure

3.4 Labelers and Feed Generators

3.5 User Identity

4 Related Work

5 Conclusions, Acknowledgments, and References

5 CONCLUSIONS

Bluesky and the AT Protocol are a new approach to social media. While some decentralized systems prioritize censorship resistance, we believe that a good user experience requires explicitly addressing problematic content such as harassment and misinformation. We therefore make moderation a first-class concern that is handled separately from infrastructure hosting, and we provide strong mechanisms for users to control the content they see.

Our open architecture allows a pluralistic system in which there is no global consensus on what content is acceptable. A user on a self-hosted or loosely moderated PDS may post controversial content, but they are not entitled to the attention of others: App Views may choose not to index the content, and clients may ignore it depending on the user’s moderation settings. This philosophy is sometimes described as “free speech, but not free reach” [18].

The AT Protocol provides cryptographically authenticated data, but our implementation pairs it with custodial key management to provide a familiar user experience. The system is open to thirdparty clients and alternative PDS hosts, and anybody can index the network using real-time streams for low-latency updates. This reduces the dependency on any one provider, since every part of the system can be run by multiple competing providers, and users can switch providers with minimal friction (in particular, without changing username, and without losing any of their content or social graph). The AT Protocol is also extensible to other social modes besides microblogging.

ACKNOWLEDGMENTS

Martin Kleppmann is supported by the Volkswagen Foundation and crowdfunding supporters including Mintter and SoftwareMill.

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