What It Is
SimpleX Chat is a messenger and messaging network that avoids user identifiers in the usual sense. Privacy is the project’s main architectural principle.
Unlike services where an account is tied to a phone number, username, or permanent ID, SimpleX builds connections between people differently to reduce metadata.
What Is Inside
The repository contains apps for iOS, Android, and desktop systems, along with protocol documentation and server components. Much of the core code is Haskell.
The project uses end-to-end encryption and explains why it builds a network without global identifiers. For a private messenger, that is a foundation, not decoration.
How People Use It
A user installs the app, creates a private connection with another person, and communicates without publishing a permanent name or number inside the SimpleX network.
The project is interesting to people who care not only about message content, but also about reducing communication traces: who is connected, where an address lives, and how long an identifier exists.
Example
The example is not code; it shows the connection model. Instead of one public address, every relationship can have its own channel.
Connection Model
The diagram shows separate connections: one user does not need a single public identifier for every contact.
Alice device
-> connection A with Bob
-> connection B with Team
-> connection C with Support
No global username is required for all contacts.Strengths And Limits
SimpleX’s strength is a strict view of privacy. It tries to reduce metadata, not only encrypt message content.
The limitation is network effect. Even a strong private system is useful only when the needed contacts are there and account recovery is understandable.
Project Context
SimpleX Chat is maintained in the simplex-chat/simplex-chat repository; its public project history starts on 2019-12-21. GitHub reports the primary language as Haskell, and the license as AGPL-3.0. The project also has a dedicated site: https://simplex.chat.
For a catalog page, this context matters because the reader sees a real project with an owner, license, technical base, and public change history rather than an abstract name.