Zipp

Private end-to-end encrypted messaging platform with a Node.js/Fastify backend and a Flutter client (web, desktop, mobile).

Project structure

server/     Node.js backend (Fastify, Prisma, PostgreSQL)
client/     Flutter client (web, Linux desktop, Android)
nix/        Nix packaging & NixOS module

NixOS deployment

Zipp is packaged as a Nix flake. Add it as an input to your NixOS config:

# flake.nix
inputs.zipp = {
  url = "github:SinisterSwiss/Zipp";
  inputs.nixpkgs.follows = "nixpkgs";
};

Server module

Import the NixOS module and configure the service:

# In your modules list:
zipp.nixosModules.default

# In a module file:
services.zipp = {
  enable    = true;
  domain    = "messaging.example.com";
  user      = "myuser";
  acmeEmail = "admin@example.com";

  settings = {
    serverUrl    = "https://messaging.example.com";
    allowSignups = true;

    smtp = {
      host = "smtp.gmail.com";
      user = "you@gmail.com";
      from = "Zipp <noreply@example.com>";
    };
  };

  # Secrets via sops-nix (recommended):
  secrets.databaseUrlFile      = config.sops.secrets."zipp/databaseUrl".path;
  secrets.sessionSecretFile    = config.sops.secrets."zipp/sessionSecret".path;
  secrets.argon2PepperFile     = config.sops.secrets."zipp/argon2Pepper".path;
  secrets.googleClientIdFile   = config.sops.secrets."zipp/googleClientId".path;
  secrets.googleClientSecretFile = config.sops.secrets."zipp/googleClientSecret".path;
  secrets.smtpPassFile         = config.sops.secrets."zipp/smtpPass".path;

  # Or set secrets directly (ends up in the Nix store -- fine for testing):
  # secrets.sessionSecret = "my-dev-secret-at-least-32-characters";
};

The module sets up:

• A rootless systemd user service running the Node.js server
• Nginx reverse proxy with SSL (ACME/Let's Encrypt)
• Data directories under /var/lib/zipp/

All available options are documented in nix/module.nix.

Desktop client

The client is a pre-built Flutter Linux desktop app. Build it, then install via your home-manager config:

cd client
nix develop        # enter the Flutter dev shell
flutter build linux --release
./deploy-linux.sh  # copies bundle to client/bundle/

Then in your NixOS config:

home.packages = [
  (pkgs.callPackage "${inputs.zipp}/nix/client.nix" {
    serverUrl = "https://messaging.example.com";
  })
];

The serverUrl is injected as the ZIPP_SERVER_URL environment variable at runtime.

Web client

Build and deploy the Flutter web app:

cd client
nix develop
flutter build web --release

Copy client/build/web/ to your web root (default: /var/lib/zipp/web/).

Development

Each subdirectory has its own dev shell:

cd server && nix develop    # Node.js 24 + Prisma engines
cd client && nix develop    # Flutter + Android SDK + desktop deps

See server/README.md for backend setup details.

License

All Rights Reserved