feat: add native module realtime transport

packages/module-ui-sdk/tests/browser-boundary/supported.tsx

@@ -17,7 +17,16 @@ export default defineModuleUi({
     container.textContent = describePrincipal(context.principal);
     void context.api.request("records");
     void context.permissions.has("example.records.read");
+    const subscription = context.realtime.subscribe<{ readonly count: number }>("record-count", {
+      onSnapshot(state, sequence) {
+        container.textContent = `${state.count}:${sequence}`;
+      },
+      onStatus(status) {
+        container.setAttribute("data-realtime", status);
+      },
+    });
     return () => {
+      subscription.close();
       container.textContent = "";
     };
   },

packages/module-ui-sdk/tests/module-ui-contract.test.ts

@@ -6,6 +6,7 @@ import {
   type ModuleUiApiClient,
   type ModuleUiDefinition,
   type ModuleUiHostContext,
+  type ModuleUiRealtimeClient,
   parseModuleUiDefinition,
   parseModuleUiExport,
 } from "../src/index.js";
@@ -19,6 +20,10 @@ function validDefinition(): ModuleUiDefinition {
  * contract, and this package deliberately does not take a DOM dependency to obtain one. */
 const noop = (): void => undefined;
 
+const noopRealtime: ModuleUiRealtimeClient = Object.freeze({
+  subscribe: () => Object.freeze({ close: noop }),
+});
+
 function fakeContainer(): Element & { textContent: string } {
   return { textContent: "" } as unknown as Element & { textContent: string };
 }
@@ -131,6 +136,7 @@ describe("the same module UI artifact hosted by two different hosts", () => {
         api,
         principal: { kind: "anonymous" },
         permissions: { has: () => canPublish },
+        realtime: noopRealtime,
       },
     };
   }
@@ -154,6 +160,7 @@ describe("the same module UI artifact hosted by two different hosts", () => {
         api,
         principal: { kind: "anonymous" },
         permissions: { has: () => canPublish },
+        realtime: noopRealtime,
       },
     };
   }