A new startup called Germ is bringing end-to-end encrypted messaging to the Bluesky social network, allowing its users to have a more secure option for chats than Bluesky’s existing DMs. After over two years of development, the service is launching its encrypted DMs for Bluesky into beta this week, with plans to gradually onboard new testers ahead of a public launch.
In time, the technology that Germ is building, much of which is open sourced, could allow Bluesky itself to introduce encrypted messaging into its own app.
Germ was designed to offer an alternative to existing end-to-end encrypted platforms that dominate globally, like iMessage, Signal, and WhatsApp. Germ takes advantage of newer technologies, like Messaging Layer Security (MLS), a new standard approved by the Internet Engineering Task Force (IETF), and the AT Protocol (or AT Proto), which powers Bluesky.
However, instead of requiring a user’s phone number as some messaging apps do, Germ integrates with AT Proto. This allows Germ users to securely chat with friends from Bluesky and the wider open social web, including apps like Flashes and Skylight, but with added controls over the user experience.
For instance, you can choose to accept DMs from people you follow on Bluesky, or you could configure it so that only you can initiate chats with other people. Plus, when you block a user in Germ, you can choose whether you want to only block them in Germ or if you want to block them across Bluesky and other AT Proto-powered apps as well.
The concept for Germ comes from co-founders Tessa Brown (CEO), a communications scholar who previously taught at Stanford, and Mark Xue, who worked as a privacy engineer at Apple on technologies like FaceTime and iMessage.
Brown’s studies led her to realize that access to private communications was fundamental to the health of social networks.
“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 tells TechCrunch. “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,” she adds.
Xue, meanwhile, came out of Apple believing that the use of phone numbers and telephony is a dated technology to serve as the basis for secure communications, and wanted to build something new.
Today, Germ’s service works by way of a “magic link,” which is generated for you and pasted into your Bluesky bio. When another Bluesky user on iOS clicks this link, they can immediately chat with you without downloading a new app from the App Store. To make this possible, Germ takes advantage of underutilized Apple technology called App Clips, which allow users to run a portion of an app’s code on their device without installing the full app.
Today, app clips are used for miscellaneous one-off type transactions, like paying for parking via a QR code. But in Germ’s case, they allow for quick chats.
While the user experience is simple enough, the technology behind it is not. The link itself is actually a cryptographic key that authenticates the user’s AT Proto identity to confirm that the user is the person associated with that Bluesky handle.
From the Germ app clip, you can choose to install the Germ iOS app, which offers more controls, access to your friends list, and now, Bluesky pairing.
The pairing feature was somewhat finicky in our tests, but we are running the iOS 26 developer beta, which may be causing complications. (To work around the issue, we started the chat from the app clip first, before trying to authenticate from the installed app.)
Brown tells TechCrunch that she’s excited about building within the Bluesky community, given the app’s growing cultural impact, which has attracted big names in U.S. politics, like Barack Obama, Hillary Clinton, and other representatives, senators, and governors, to join.
Given that Germ is ahead of the Bluesky team itself in building encrypted messaging technology, Brown is hopeful that Germ’s protocol could be more broadly adopted by Bluesky and others in the future.
While currently free to use, the Germ app may later introduce a premium subscription upgrade that offers more advanced services, including private AI services, personalization tools, and more.
The four-person startup has raised pre-seed funding from angel investors, including a co-author of MLS and other trust and safety experts. Institutional investors include K5 Global and Mozilla Ventures. The company hopes to raise additional funds for an Android version in the future.
