Toggle features live
A customization dialog enables, disables, and reprioritizes plugins at runtime. The runtime detaches losers, attaches winners, and keeps the session coherent across the swap.
Plugin Kit
For apps where "just add a flag" has become the beginning of every bug.
Plugin Kit is a runtime for Dart apps that have grown into platforms. Features get real lifecycles. Services get replaceable, prioritized implementations. Sessions stay sealed. Events flow between parts of your app that have never been formally introduced.
What it unlocks
Section titled “What it unlocks”Swap features, not screens
A model selector, search box, or editor tool targets a slot instead of a concrete service. The UI stays put while plugins compete underneath it.
Open two sessions safely
Two chats, documents, or workspaces get separate registries, buses, and plugin state by default. No mystery leaks because one tab forgot to clean up after itself.
Add a 'hooks' pipeline
Plugins inspect an outgoing action, inject context, enrich metadata, or stop it entirely. The button that started it does not need to know who helped or interfered.
Most apps don’t need this
Section titled “Most apps don’t need this”If your app has one HTTP client, one auth service, and a few screens that call them, use the boring thing. Plugin Kit earns its weight when behavior needs to be replaced, layered, disabled, overridden, or vetoed while the app is running, and settings have stopped being data your app reads and started being something that actively reshapes the system. If you are wiring features by hand and noticing the same scaffolding for the third time, this is built for that case.
Four primitives, composed
Section titled “Four primitives, composed”Plugins
Lifecycle-aware feature units. Global or session scope, with register,
attach, detach, and live settings reconciliation as first-class hooks.
Services
A priority-based registry where multiple plugins can claim the same slot. Higher priority wins, the loser stays reachable as a fallback.
Events
A typed, priority-ordered bus for fire-and-forget and request/response. Handlers run in order, so plugins can mutate, observe, or short-circuit.
Sessions
Isolated execution scopes. Each gets its own registry, bus, and context. Open ten and close one without touching the others.
Where to start
Section titled “Where to start” Why Plugin Kit? The short read. The origin story, the symptoms that motivate the library, and the design decisions that follow.
Show me it running Two plugins, one slot, the runtime picks the winner. Eight steps, full walkthrough.
Show me the mental model Plugins, services, events, sessions. Four pieces, and everything else is composition.
Read code, not docs A miniature workflow built out of plugins, one concept per file. Many readers go here first.
Building on Flutter?
Section titled “Building on Flutter?” Flutter Integration The manual recipe. Where the runtime lives in a StatefulWidget, how widgets hear about plugin changes, how plugin-provided UI is resolved.
flutter_plugin_kit Optional companion package. Scope widgets, a State mixin that auto-cancels bus subscriptions, BuildContext.watchEvent extensions.
State Management Bridges ChangeNotifier, flutter_bloc Cubit, Riverpod AsyncNotifier, signals_flutter, MobX, GetIt, plain setState. Every recipe is verified by widget tests.
Plugin Kit Dialog A drop-in customization UI for any PluginRuntime. Three tabs, zero settings-screens-per-plugin code.