Render Google A2UI v0.9 surfaces natively via AG-UI streaming, with CopilotKit-style generative UI actions, closed component catalog, local-first JSON‑Pointer bindings and host-owned theming.
Render Google A2UI v0.9 surfaces natively on Compose Multiplatform, driven over AG-UI streaming transport, with CopilotKit-style generative-UI actions layered on top.
Kotlin Multiplatform. Material3 catalog. Host-owned theming. No WebView.
Closed component vocabulary. The catalog is the trust boundary. Agents cannot invent widgets the client has not registered — unknown components render a muted FallbackPlaceholder, never arbitrary code. Every rendered pixel comes from a factory you shipped in the binary.
Local-first input binding. Inputs mutate the local DataModel synchronously via JSON Pointer paths — TextField, Slider, CheckBox, ChoicePicker, DateTimeInput all two-way bind without a server round-trip. Only explicit event declarations flush to the agent. IME latency stays native.
Host-owned theming. Agents supply semantic hints (primary, error, variants). Compose resolves them through MaterialTheme. Off-brand colors and inaccessible contrast are physically not expressible in the wire format.
Design rationale in SYNTHESIS.md; module graph in ARCHITECTURE.md.
Add the dependency (planned coords — not yet published to Maven Central):
// build.gradle.kts
dependencies {
implementation("dev.mikepenz.a2cui:a2cui-compose:0.1.0-a02")
// optional:
// implementation("dev.mikepenz.a2cui:a2cui-agui:0.1.0-a02")
// implementation("dev.mikepenz.a2cui:a2cui-actions:0.1.0-a02")
}
Minimum viable surface:
@Composable
fun Demo() {
val transport = remember { FakeTransport() }
val controller = rememberSurfaceController(
catalogs = listOf(Material3BasicCatalog),
transport = transport,
)
LaunchedEffect(transport) {
transport.emit(CREATE_SURFACE)
transport.emit(UPDATE_COMPONENTS)
}
A2cuiSurface(surfaceId = "main", controller = controller)
}
First frames to paste in:
{ "version": "v0.9",
"createSurface": { "surfaceId": "main",
"catalogId": "https://a2ui.org/specification/v0_9/basic_catalog.json" } }
Swap FakeTransport() for SseTransport(...) or WebSocketTransport(...) when you wire a real agent.
Per STATUS.md §2.2:
One-line summary per publishable module. Each links to its own README (authored separately).
Runnable backends that emit AG-UI events wrapping A2UI frames — point :a2cui-sample-live (or your own host) at them:
integrations/pydantic-ai/ — Python + Pydantic AI scaffold.integrations/mastra/ — TypeScript + Mastra scaffold.Both speak AG-UI over SSE with CUSTOM { name: "a2ui" } frames carrying A2UI v0.9 JSON.
Full execution log, test matrix, and deferrals: STATUS.md.
CONTRIBUTING.md is WIP — see CONTRIBUTING.md once it lands. In the meantime, issues and PRs are welcome; run ./gradlew assemble check before opening one.
Apache-2.0. See gradle.properties for POM metadata.
{ "version": "v0.9",
"updateComponents": { "surfaceId": "main", "components": [
{ "id": "root", "component": "Column", "children": ["hello", "go"] },
{ "id": "hello", "component": "Text", "text": "Hello from an agent", "variant": "h2" },
{ "id": "go", "component": "Button", "label": "Continue",
"action": { "event": { "name": "submit" } } }
] } }
| Target | :a2cui-core / -transport / -compose / -agui / -actions / -adaptive-cards | :a2cui-codegen |
|---|
| android | yes | — |
| jvm (desktop) | yes | yes |
| iosArm64 / iosX64 / iosSimulatorArm64 | yes | — |
| macosArm64 / macosX64 | yes | — |
| js | yes | — |
| wasmJs | yes | — |
:a2cui-core — A2UI v0.9 wire types, parser, DataModel, JsonPointer, BindingResolver. Pure Kotlin, zero Compose.:a2cui-transport — A2uiTransport interface plus Ktor SseTransport, WebSocketTransport, and FakeTransport for tests.:a2cui-compose — SurfaceController, A2cuiSurface, ComponentRegistry, and the 15-component Material3BasicCatalog.:a2cui-agui — AG-UI event decoder, AguiA2cuiBridge, AguiStateReducer (JSON Patch), interrupt awaiter, rememberCoAgentState.:a2cui-actions — CopilotKit-style rememberAction / rememberReadable with typed streaming-args decoding.:a2cui-adaptive-cards — Adaptive Cards v1.6 → A2UI v0.9 mapper for Copilot Studio interop.:a2cui-codegen — KSP processor for @A2uiComponent emitting catalog factories, JSON Schema, and tool-prompt fragments.:a2cui-codegen-annotations — multiplatform annotations consumed by :a2cui-codegen.a2cui-sample — Compose Desktop app wrapping the shared sample in a Window. Run: ./gradlew :a2cui-sample:run.a2cui-sample-shared — A2cuiSampleApp composable + SampleFrames, shared across desktop / android / ios hosts.a2cui-sample-android — MainActivity hosting the shared sample inside an Activity.a2cui-sample-ios — SampleViewController exposing the shared sample as a ComposeUIViewController.a2cui-sample-live — desktop host spinning up MockAguiServer in-process and wiring SseTransport → AguiA2cuiBridge → A2cuiSurface.a2cui-sample-custom-catalog — dogfoods :a2cui-codegen: annotated RatingFactory + BadgeFactory compile into a CustomDemoCatalog.Material3BasicCatalog, AguiA2cuiBridge, rememberAction, :a2cui-adaptive-cards, :a2cui-codegen. 125 tests green on JVM; Android / iOS / macOS / JS / WASM compile.@ExperimentalA2uiDraft primitives (DataModelPatch, ScrollTo, Viewport, Conditional) ahead of upstream A2UI spec changes. AG-UI interrupt resume semantics still draft.WebResource escape-hatch for MCP Apps.Surfaced from shared tags and platforms — no rankings paid for.