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LlmBench Kotlin Multiplatform Architecture

Explore the shared KMP core, platform clients, and Compose-first UI strategy that power LlmBench across Android, with planned desktop and iOS support.
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LlmBench is built as a Kotlin Multiplatform (KMP) workspace that separates shared domain logic from platform-specific clients. This architecture lets Android, desktop, and iOS clients reuse the same core while preserving native capabilities where they matter most.

Shared module#

The shared Kotlin Multiplatform module contains portable logic that runs on every target:

Provider/model registry

Central registry of supported providers and models, including metadata and adapter interfaces.

Profile + prompt tools

Utilities for parsing, validating, and applying portable AI profiles and prompts.

Portable domain logic

Business rules, comparison logic, and other domain code that does not depend on platform APIs.

Platform clients#

Each platform owns the parts of the stack that require native behavior:

Android app#

The Android app is the first shipping client and owns:

  • WebView host and file chooser: Renders provider web interfaces and handles file uploads through the platform picker
  • Provider tweaks and mobile performance: Applies userscripts and CSS adaptations for mobile layout
  • Custom Tabs, intents, and Keystore: Handles external authentication flows and secure credential storage

Desktop app (planned)#

A desktop client will reuse the shared KMP core while providing native WebView or browser integration appropriate for desktop operating systems.

iOS app (planned)#

An iOS client will reuse the same shared core with platform-specific WebView and storage implementations.

Backend strategy#

Backends are optional, not the default. LlmBench prefers client-side processing where possible. If a feature truly needs a backend, the project prefers a small stateless service and evaluates free tiers (Cloudflare, Google Cloud, AWS, Oracle) based on actual requirements rather than choosing infrastructure first.

UI strategy: Compose-first#

LlmBench uses Jetpack Compose as the primary UI toolkit. Shared UI moves into Compose Multiplatform only where it does not weaken:

  • Native WebView behavior
  • File upload handling
  • Authentication flows
  • Secure storage access
Note

Mobile UX is a product constraint: long chats must stay responsive, file upload must work, and provider tweaks should reduce wasted chrome and animation without breaking provider pages.

Architecture diagram#

ProfilesRoadmap