Atmo

Atmo is a Bluesky (AT Protocol) client for macOS, iOS, iPadOS, watchOS, and Ubuntu Linux, built on the ATProtoKit library.

Layout

AtmoCore/      Platform-neutral model & service layer (SPM package).
               Models, ATProtoService, stores, view models. No UI
               imports — builds and tests on macOS and Linux.
Apple/         The SwiftUI app (macOS/iOS/iPadOS) and the watchOS app
               (Apple/Watch), plus the Apple implementations of
               AtmoCore's platform seams (Keychain, iCloud KVS,
               Spotlight) in Apple/Platform.
LinuxApp/      The GNOME app: GTK4/libadwaita via Adwaita for Swift, on
               the same AtmoCore. See LinuxApp/PORTING.md for the
               feature parity tracker and build instructions.
Resources/     Asset catalog, Info.plist fragment, entitlements.
project.yml    XcodeGen definition for Atmo.xcodeproj (targets: Atmo for
               iOS+macOS, AtmoWatch for watchOS).
snap/          Snapcraft packaging for the Ubuntu app.

Building

Apple platforms — open Atmo.xcodeproj (or regenerate it after editing project.yml):

xcodegen generate

Schemes: Atmo (iPhone/iPad/Mac), AtmoWatch (Apple Watch).

Shared core — pure SwiftPM, with tests:

cd AtmoCore && swift test

Linux — see LinuxApp/PORTING.md (dev container for development, snapcraft for the Ubuntu package).

Architecture

The rule that keeps five platforms maintainable: AtmoCore is the source of truth for models, session management, and feed/notification/composer logic. UI layers (SwiftUI and GTK) hold no business logic; anything platform-specific AtmoCore needs (credential storage, synced key-value store, search indexing, lifecycle notifications) is declared as a protocol seam in AtmoCore/Sources/AtmoCore/Platform and installed at launch via Atmo.platform.

Sessions use App Passwords via ATProtoKit's ATProtocolConfiguration (ATCredentialStore + a stable session UUID persisted per install).