Bluesky (social network)

Bluesky, also known as Bluesky Social, is a decentralized microblogging social platform and a public benefit corporation based in the United States. Jay Graber serves as the company's CEO and XMPP creator Jeremie Miller sit on its board of directors.

In addition to its website, the service is also accessible via apps for iOS and Android. The service is focused on microblogging, and has been called "Twitter-like".

Service history
Bluesky was described in 2021 as an initiative to develop a decentralized social network protocol, in which multiple social networks, each with its own systems of curation and moderation, interact with other social networks through an open standard. Each social network using the protocol would be called an "application". As of 2023, Bluesky operates its own official network, Bluesky Social, a centralized service running on open-source software for its servers and client apps, with their initial protocol implementation released under the MIT license. Neither the protocol nor service claimed to use blockchain technology in 2022.

Frequent users have called posts on the platform "skeets" (a portmanteau of "sky" and "tweets", but also a slang word for ejaculation   ), despite CEO Jay Graber pleading with users not to call them that.

The Authenticated Data Experiment (ADX), in mid-2022, was Bluesky's first early protocol release. It used personal data repositories, intended to be controlled by individual users, that social networks would optionally support. The stated purpose was to let users post messages without necessarily affecting their visibility to other users, as primary storage of the data would remain in the personal data repository while networks would handle the distribution to other users. The ATP FAQ later described this distinction as a division between "speech" and "reach" layers. Bluesky released a simplified version as the "AT Protocol" in October 2022, alongside technical documentation.

Bluesky started a waitlist in October 2022 for a service that would use the protocol. At the time of release, Bluesky only addressed interoperability and had not explained how it would address platform moderation and monetization. In February 2023, the Bluesky app was released for iOS as an invitation-only beta, and the service was available only to users who had received an invitation code, either from the company or from an existing user. Reviewing the app, TechCrunch called it "a functional, if still rather bare-bones, Twitter-like experience."

In April 2023, it was released for Android. After the launch of the Android app, the social network reached about 50,000 users in April 2023. The launch surfaced technical issues, including a bug that created incorrect notifications. Bluesky Social was made open source under the MIT license in May 2023.

On May 26, 2023, Bluesky launched a feature it called "Custom Feeds", with the goal of promoting algorithmic choice. Bluesky developer Paul Frazee stated that "In future updates [Bluesky] will make it easy for users to create custom feeds in-app." Third-party tools to publish Custom Feeds on Bluesky have been created by independent developers, including a popular client named Skyfeed.

In September 2023, Bluesky Social reached 1 million registered users, and in November, it surpassed 2 million users.

In December 2023, Bluesky announced a new company logo, which was also used as the icon for the official app and website. This icon was a blue butterfly, inspired by existing users' usage of the butterfly emoji to indicate their handles on the service. The launch of this new icon corresponded with the release of a public view for posts on the network, allowing those without accounts on the service to view its posts.

The platform became open to all public registrations on 6 February 2024, when the previous invitation-only format was dropped.

Company history
Twitter's then-CEO Jack Dorsey first announced the Bluesky initiative in 2019 on Twitter. The company's Chief Technology Officer (and later CEO) Parag Agrawal was its manager, inviting initial working group members in early 2020. The group expanded with representatives from existing decentralized networks Mastodon and ActivityPub. The group coordinated through a chat hosted over the Matrix protocol. Twitter commissioned Jay Graber of the Happening decentralized social network to compose a technical review of the decentralized social network landscape. She was hired to lead Bluesky in August 2021. Bluesky formally incorporated in late 2021 as a public benefit LLC separate from Twitter.

Twitter executives approved of the initiative's scope and goals, which include what the protocol itself should encompass and what should be left to applications (the social networks built atop the standard). Some of these goals include letting applications customize their system of moderation, making applications responsible for compliance and takedown requests, and preventing virality algorithms from reinforcing controversy and moral outrage. The working group did not have a consensus toward these goals, so Twitter decided to field individual proposals, which ranged from reinforcing existing standards to endorsing standard interoperability, letting usage data decide where to invest. In early 2021, Bluesky was in a research phase, with 40–50 people from the decentralized technology community active in assessing options and assembling proposals for the protocol. Bluesky's first three employees were hired in March 2022. Around the same time, Dorsey acknowledged Bluesky's slow progress.

Twitter's blockchain division, newly announced in November 2021, planned to work with the Bluesky initiative. The division head resigned after Elon Musk bought Twitter in late 2022. Staff departures made the team's future remit unclear. Musk's takeover did not immediately affect Bluesky's operations, as a separate entity, but does affect its long-term funding. Bluesky had received $13 million from Twitter via Musk's initial offer in April 2022. Adi Robertson for The Verge wrote that even with Bluesky's independence, Musk's ownership of Twitter would make Bluesky easy to defund, with its main executive proponents having left Twitter.

On July 5, 2023, Bluesky announced it had raised $8 million in a seed funding round. The seed round was led by Neo, a firm with partners like Code.org co-founder Ali Partovi and former Twitter PM Suzanne Xie, and included other investors such as Joe Beda (co-creator of Kubernetes), Bob Young of Red Hat, Amjad Masad of Replit, Amir Shevat, Heather Meeker, Jeromy Johnson, and Automattic. Bluesky plans to use the funds to grow its team, manage operations, pay for infrastructure costs, and build out the AT Protocol technology that it runs on.

Prior to the seed round, Bluesky's website described the company as a Public Benefit LLC owned by Graber and other Bluesky employees. Post-seed round, the company describes itself as a public-benefit C Corp. The company has not publicly disclosed its charter.

On May 4, 2024, Jack Dorsey, Bluesky funder and initiator, announced on X that he was no longer on Bluesky's board, and Bluesky confirmed his departure.

AT Protocol
Bluesky unveiled open source code in May 2022 for an early version of its distributed social network protocol, Authenticated Data Experiment (ADX), since renamed the Authenticated Transfer (AT) Protocol. The team opened its early code and placed it under an MIT License so that the development process would be seen in public.

The AT Protocol's initial federation architecture centers around three main services: a Personal Data Server (PDS), Relay (previously referred to as a Big Graph Service, or BGS), and an AppView. A PDS is a server which hosts user data in "Data Repositories", which utilize a Merkle tree. The PDS also handles user authentication and manages the signing keys for its hosted repositories. A Relay is described as analogous to an indexer on the web, ingesting repositories from a variety of different PDS hosts and serving them in a single unified stream for other services to ingest. AppViews, meanwhile, are services which consume data from a Relay and hydrate that data to provide behavior for specific clients, e.g. the microblogging feature set for the Bluesky Social app.