Germ, a new startup, is introducing end-to-end encrypted direct messages (DMs) to the Bluesky social network, providing a more secure communication option for users. Launching this week in beta, the service aims to onboard new testers gradually before its public release, marking the culmination of over two years of development.
Germ’s technology, with a significant portion being open-sourced, holds the potential for Bluesky to integrate encrypted messaging directly into its native application. Designed as an alternative to established end-to-end encrypted platforms like iMessage, Signal, and WhatsApp, Germ leverages advanced technologies such as Messaging Layer Security (MLS) and the AT Protocol (ATProto), which powers Bluesky.
Unlike some messaging apps that rely on phone numbers, Germ integrates directly with ATProto. This allows users to engage in secure chats with their Bluesky contacts and across the broader open social web, including applications like Flashes and Skylight, all while providing enhanced user controls. Users gain the ability to manage who can send them direct messages. For example, users can configure their settings to accept DMs only from those they follow on Bluesky or restrict communication to initiating chats exclusively.
Furthermore, Germ offers nuanced blocking options. Users can choose to block another user solely within Germ or extend the block across Bluesky and other applications powered by ATProto. This provides granular control over interactions within the decentralized social network.
The concept for Germ originated from co-founders Tessa Brown (CEO) and Mark Xue. Brown, a communications scholar and former Stanford instructor, and Xue, a former Apple privacy engineer who worked on FaceTime and iMessage, bring complementary expertise to the project.
Brown’s academic research highlighted the critical role of private communication in fostering healthy social networks. She told TechCrunch, “We know that, psychologically, you can’t build a good relationship with people if you feel like you’re being stared at and manipulated all the time. And that’s really what social media is today.” Brown added, “So I came out of that work with a really strong conviction around end-to-end encrypted messaging as kind of the centerpiece of what I thought was the future of social media and the future of communication.” This conviction underscores the importance of secure messaging as a foundational element for future social media platforms.
Xue’s experience at Apple led him to question the reliance on phone numbers and traditional telephony as the foundation for secure communication systems. He sought to develop a new system that moved beyond these dated technologies.
Germ currently employs a “magic link” system. A unique link is generated for each user, which they then paste into their Bluesky bio. When another Bluesky user on iOS clicks this link, they can start chatting immediately, without the need to download a separate app from the App Store. This functionality is enabled by Apple’s App Clips technology, which allows users to run a portion of an application’s code without a full installation.
App Clips are typically used for simple, single-purpose transactions, such as paying for parking via a QR code. Germ, however, leverages App Clips to facilitate quick and seamless chat experiences.
While the user experience is designed to be straightforward, the underlying technology is complex. The “magic link” is essentially a cryptographic key that authenticates the user’s ATProto identity, verifying that the user is indeed associated with the claimed Bluesky handle. This cryptographic authentication ensures secure communication from the outset.
From the Germ App Clip, users have the option to install the full Germ iOS app, which unlocks additional features, including access to friends lists and Bluesky pairing functionality. During testing, the pairing feature experienced some difficulties, potentially due to the device running the iOS 26 developer beta. A workaround involved initiating the chat from the App Clip before attempting authentication from the installed app.
Brown expressed enthusiasm for building within the Bluesky community, citing the app’s increasing cultural influence and its adoption by prominent figures in U.S. politics, including Barack Obama, Hillary Clinton, and various representatives, senators, and governors. This broad adoption highlights the growing importance of Bluesky as a platform for public discourse.
Given Germ’s progress in developing encrypted messaging technology, Brown hopes that Germ’s protocol could be widely adopted by Bluesky and other platforms. This could potentially establish Germ’s technology as a standard for secure communication within decentralized social networks.
Although currently offered free of charge, Germ may introduce a premium subscription model in the future. This subscription could offer advanced services such as private AI tools, personalization options, and other enhanced functionalities. This potential premium service aims to cater to users seeking more advanced features and customization options.
The startup, comprised of four individuals, has secured pre-seed funding from angel investors, including a co-author of MLS and trust and safety experts. Institutional investors include K5 Global and Mozilla Ventures. The company intends to raise further capital to develop an Android version of the application. This planned expansion aims to broaden Germ’s accessibility and reach a wider user base.
