[stack] Add system vats

packages/extension/package.json

@@ -49,6 +49,7 @@
     "@metamask/kernel-ui": "workspace:^",
     "@metamask/kernel-utils": "workspace:^",
     "@metamask/logger": "workspace:^",
+    "@metamask/ocap-kernel": "workspace:^",
     "@metamask/streams": "workspace:^",
     "react": "^18.3.1",
     "react-dom": "^18.3.1",

packages/extension/src/background.ts

@@ -1,13 +1,7 @@
 import { E } from '@endo/eventual-send';
-import {
-  makeBackgroundCapTP,
-  makeCapTPNotification,
-  isCapTPNotification,
-  getCapTPMessage,
-} from '@metamask/kernel-browser-runtime';
-import type { CapTPMessage } from '@metamask/kernel-browser-runtime';
+import { makeBackgroundHostVat } from '@metamask/kernel-browser-runtime';
 import defaultSubcluster from '@metamask/kernel-browser-runtime/default-cluster';
-import { delay, isJsonRpcMessage, stringify } from '@metamask/kernel-utils';
+import { delay, isJsonRpcMessage } from '@metamask/kernel-utils';
 import type { JsonRpcMessage } from '@metamask/kernel-utils';
 import { Logger } from '@metamask/logger';
 import { ChromeRuntimeDuplexStream } from '@metamask/streams/browser';
@@ -21,7 +15,7 @@ let bootPromise: Promise<void> | null = null;
 // With this we can click the extension action button to wake up the service worker.
 chrome.action.onClicked.addListener(() => {
   globalThis.kernel !== undefined &&
-    E(globalThis.kernel).ping().catch(logger.error);
+    E(globalThis.kernel).getStatus().catch(logger.error);
 });
 
 // Install/update
@@ -87,65 +81,38 @@ async function main(): Promise<void> {
   // Without this delay, sending messages via the chrome.runtime API can fail.
   await delay(50);
 
-  // Create stream for CapTP messages
+  // Create stream for JSON-RPC messages to kernel
   const offscreenStream = await ChromeRuntimeDuplexStream.make<
     JsonRpcMessage,
     JsonRpcMessage
   >(chrome.runtime, 'background', 'offscreen', isJsonRpcMessage);
 
-  // Set up CapTP for E() based communication with the kernel
-  const backgroundCapTP = makeBackgroundCapTP({
-    send: (captpMessage: CapTPMessage) => {
-      const notification = makeCapTPNotification(captpMessage);
-      offscreenStream.write(notification).catch((error) => {
-        logger.error('Failed to send CapTP message:', error);
-      });
-    },
-  });
+  // Create host vat - captures kernelFacet from bootstrap automatically
+  const hostVat = makeBackgroundHostVat({ logger });
 
-  // Get the kernel remote presence
-  const kernelP = backgroundCapTP.getKernel();
-  globalThis.kernel = kernelP;
-
-  // Handle incoming CapTP messages from the kernel
-  const drainPromise = offscreenStream.drain((message) => {
-    if (isCapTPNotification(message)) {
-      const captpMessage = getCapTPMessage(message);
-      backgroundCapTP.dispatch(captpMessage);
-    } else {
-      throw new Error(`Unexpected message: ${stringify(message)}`);
-    }
-  });
-  drainPromise.catch(logger.error);
+  // Connect to kernel via offscreen pipe
+  hostVat.connect(offscreenStream);
 
-  try {
-    await E(kernelP).ping();
-    await startDefaultSubcluster();
-  } catch (error) {
-    offscreenStream.throw(error as Error).catch(logger.error);
-  }
+  globalThis.kernel = hostVat.kernelFacetPromise;
 
-  try {
-    await drainPromise;
-  } catch (error) {
-    const finalError = new Error('Offscreen connection closed unexpectedly', {
-      cause: error,
-    });
-    backgroundCapTP.abort(finalError);
-    throw finalError;
-  }
+  // Verify connectivity and start default subcluster
+  await E(kernel).getStatus();
+  await startDefaultSubcluster();
 }
 
 /**
  * Idempotently starts the default subcluster.
+ * Must be called after globalThis.kernel is set.
  */
 async function startDefaultSubcluster(): Promise<void> {
-  const status = await E(globalThis.kernel).getStatus();
+  const { kernel } = globalThis;
+  if (kernel === undefined) {
+    throw new Error('Kernel not initialized');
+  }
 
+  const status = await E(kernel).getStatus();
   if (status.subclusters.length === 0) {
-    const result = await E(globalThis.kernel).launchSubcluster(
-      defaultSubcluster,
-    );
+    const result = await E(kernel).launchSubcluster(defaultSubcluster);
     logger.info(`Default subcluster launched: ${JSON.stringify(result)}`);
   } else {
     logger.info('Subclusters already exist. Not launching default subcluster.');

packages/extension/src/global.d.ts

@@ -1,4 +1,4 @@
-import type { KernelFacade } from '@metamask/kernel-browser-runtime';
+import type { KernelFacet } from '@metamask/ocap-kernel';
 
 // Type declarations for kernel dev console API.
 declare global {
@@ -8,15 +8,14 @@ declare global {
    *
    * @example
    * ```typescript
-   * const kernel = await kernel.getKernel();
    * const status = await E(kernel).getStatus();
    * ```
    */
   // eslint-disable-next-line no-var,id-length
   var E: typeof import('@endo/eventual-send').E;
 
   // eslint-disable-next-line no-var
-  var kernel: KernelFacade | Promise<KernelFacade>;
+  var kernel: Promise<KernelFacet> | KernelFacet;
 }
 
 export {};

packages/extension/test/e2e/control-panel.test.ts

@@ -191,19 +191,19 @@ test.describe('Control Panel', () => {
     const v3Values = [
       '{"key":"e.nextPromiseId.v3","value":"2"}',
       '{"key":"e.nextObjectId.v3","value":"1"}',
-      '{"key":"ko5.owner","value":"v3"}',
-      '{"key":"v3.c.ko5","value":"R o+0"}',
-      '{"key":"v3.c.o+0","value":"ko5"}',
-      '{"key":"v3.c.kp4","value":"R p-1"}',
-      '{"key":"v3.c.p-1","value":"kp4"}',
-      '{"key":"ko5.refCount","value":"1,1"}',
-      '{"key":"kp4.refCount","value":"2"}',
+      '{"key":"ko7.owner","value":"v3"}',
+      '{"key":"v3.c.ko7","value":"R o+0"}',
+      '{"key":"v3.c.o+0","value":"ko7"}',
+      '{"key":"v3.c.kp7","value":"R p-1"}',
+      '{"key":"v3.c.p-1","value":"kp7"}',
+      '{"key":"ko7.refCount","value":"1,1"}',
+      '{"key":"kp7.refCount","value":"2"}',
     ];
     const v1koValues = [
-      '{"key":"v1.c.ko4","value":"R o-1"}',
-      '{"key":"v1.c.o-1","value":"ko4"}',
-      '{"key":"v1.c.ko5","value":"R o-2"}',
-      '{"key":"v1.c.o-2","value":"ko5"}',
+      '{"key":"v1.c.ko6","value":"R o-1"}',
+      '{"key":"v1.c.o-1","value":"ko6"}',
+      '{"key":"v1.c.ko7","value":"R o-2"}',
+      '{"key":"v1.c.o-2","value":"ko7"}',
     ];
     await expect(
       popupPage.locator('[data-testid="message-output"]'),
@@ -263,16 +263,16 @@ test.describe('Control Panel', () => {
         popupPage.locator('[data-testid="message-output"]'),
       ).not.toContainText(value);
     }
-    // ko3 (vat root) reference still exists for v1
+    // ko6, ko7 (bob, carol vat roots) references still exist for v1
     for (const value of v1koValues) {
       await expect(
         popupPage.locator('[data-testid="message-output"]'),
       ).toContainText(value);
     }
-    // kp4 reference dropped to 1
+    // kp7 reference dropped to 1
     await expect(
       popupPage.locator('[data-testid="message-output"]'),
-    ).toContainText('{"key":"kp4.refCount","value":"1"}');
+    ).toContainText('{"key":"kp7.refCount","value":"1"}');
     await popupPage.click('button:text("Control Panel")');
     await popupPage.locator('[data-testid="accordion-header"]').first().click();
     // delete v1

packages/extension/test/e2e/object-registry.test.ts

@@ -108,7 +108,7 @@ test.describe('Object Registry', () => {
 
   test('should revoke an object', async () => {
     const owner = 'v1';
-    const v1Root = 'ko3';
+    const v1Root = 'ko5';
     const [target, method, params] = [v1Root, 'hello', '["Bob"]'];
 
     // Before revoking, we should be able to send a message to the object

packages/extension/test/e2e/remote-comms.test.ts

@@ -118,8 +118,8 @@ test.describe('Remote Communications', () => {
     await expect(targetSelect).toBeVisible();
     const options = await targetSelect.locator('option').all();
     expect(options.length).toBeGreaterThan(1);
-    await targetSelect.selectOption({ value: 'ko3' });
-    expect(await targetSelect.inputValue()).toBe('ko3');
+    await targetSelect.selectOption({ value: 'ko5' });
+    expect(await targetSelect.inputValue()).toBe('ko5');
 
     // Set method to doRunRun (the remote communication method)
     const methodInput = popupPage1.locator('[data-testid="message-method"]');

packages/kernel-browser-runtime/package.json

@@ -59,14 +59,15 @@
     "test:build": "tsx ./test/build-tests.ts",
     "test:clean": "yarn test --no-cache --coverage.clean",
     "test:dev": "yarn test --mode development",
-    "test:integration": "vitest run --config vitest.integration.config.ts",
     "test:verbose": "yarn test --reporter verbose",
     "test:watch": "vitest --config vitest.config.ts",
     "test:dev:quiet": "yarn test:dev --reporter @ocap/repo-tools/vitest-reporters/silent"
   },
   "dependencies": {
+    "@agoric/swingset-liveslots": "0.10.3-u21.0.1",
     "@endo/captp": "^4.4.8",
     "@endo/marshal": "^1.8.0",
+    "@endo/promise-kit": "^1.1.13",
     "@metamask/json-rpc-engine": "^10.2.0",
     "@metamask/kernel-errors": "workspace:^",
     "@metamask/kernel-rpc-methods": "workspace:^",
@@ -85,7 +86,6 @@
   },
   "devDependencies": {
     "@arethetypeswrong/cli": "^0.17.4",
-    "@endo/eventual-send": "^1.3.4",
     "@metamask/auto-changelog": "^5.3.0",
     "@metamask/eslint-config": "^15.0.0",
     "@metamask/eslint-config-nodejs": "^15.0.0",

packages/kernel-browser-runtime/src/host-vat/index.ts

@@ -0,0 +1,14 @@
+/**
+ * Host vat utilities for cross-process system vat communication.
+ *
+ * The host vat enables a system vat supervisor to run in a different process
+ * than the kernel. The kernel runs in a Worker, and the supervisor runs in
+ * the background script. They communicate over a stream using JSON-RPC messages
+ * and the optimistic syscall model (fire-and-forget with ['ok', null]).
+ */
+
+export { makeKernelHostVat } from './kernel-side.ts';
+export type { KernelHostVatResult } from './kernel-side.ts';
+
+export { makeBackgroundHostVat } from './supervisor-side.ts';
+export type { BackgroundHostVatResult } from './supervisor-side.ts';