fix(vscode): detect workspace before runtime registration

packages/ui/src/stores/useProjectsStore.ts

@@ -13,6 +13,7 @@ import { PROJECT_COLORS } from '@/lib/projectMeta';
 import { useSessionUIStore } from '@/sync/session-ui-store';
 import { runtimeFetch } from '@/lib/runtime-fetch';
 import { getRuntimeApiBaseUrl } from '@/lib/runtime-switch';
+import { getVSCodeBootstrapConfig, isVSCodeRuntime } from './utils/vscodeRuntime';
 
 /** Pick a color key that's least used among existing projects */
 const pickAutoColor = (projects: ProjectEntry[]): string => {
@@ -416,21 +417,11 @@ const createVSCodeWorkspaceProject = (
 };
 
 const getVSCodeWorkspaceFolders = (): VSCodeWorkspaceFolderConfig[] | null => {
-  if (typeof window === 'undefined') {
-    return null;
-  }
-
   const runtimeApis = getRegisteredRuntimeAPIs();
-  if (!runtimeApis?.runtime?.isVSCode) {
+  const config = getVSCodeBootstrapConfig();
+  if (!isVSCodeRuntime(runtimeApis, config)) {
     return null;
   }
-
-  const config = (window as unknown as {
-    __VSCODE_CONFIG__?: {
-      workspaceFolder?: unknown;
-      workspaceFolders?: unknown;
-    };
-  }).__VSCODE_CONFIG__;
   const folders = Array.isArray(config?.workspaceFolders)
     ? config.workspaceFolders
         .map((entry) => {
@@ -542,8 +533,7 @@ const getVSCodeWorkspaceProject = (): { projects: ProjectEntry[]; activeProjectI
 // Always prefer the VS Code workspace projects over any persisted multi-project registry.
 const vscodeWorkspace = getVSCodeWorkspaceProject();
 const isVSCodeProjectsRuntime = (() => {
-  if (typeof window === 'undefined') return false;
+  return isVSCodeRuntime(getRegisteredRuntimeAPIs(), getVSCodeBootstrapConfig());
-  return Boolean(getRegisteredRuntimeAPIs()?.runtime?.isVSCode);
 })();
 const effectiveInitialProjects = vscodeWorkspace?.projects ?? (isVSCodeProjectsRuntime ? [] : initialProjects);
 const persistedInitialActiveProjectId = vscodeWorkspace?.activeProjectId ?? (isVSCodeProjectsRuntime ? null : readPersistedActiveProjectId());

packages/ui/src/stores/utils/vscodeRuntime.test.ts

@@ -0,0 +1,15 @@
+import { describe, expect, test } from 'bun:test';
+import { isVSCodeRuntime } from './vscodeRuntime';
+
+describe('VS Code runtime detection', () => {
+  test('uses extension-host bootstrap config before runtime APIs are registered', () => {
+    expect(isVSCodeRuntime(null, {
+      workspaceFolder: '/workspace/project-one',
+      workspaceFolders: [{ name: 'project-one', path: '/workspace/project-one' }],
+    })).toBe(true);
+  });
+
+  test('does not classify an unregistered web runtime as VS Code', () => {
+    expect(isVSCodeRuntime(null, null)).toBe(false);
+  });
+});

packages/ui/src/stores/utils/vscodeRuntime.ts

@@ -0,0 +1,18 @@
+import type { RuntimeAPIs } from '@/lib/api/types';
+
+export interface VSCodeBootstrapConfig {
+  workspaceFolder?: unknown;
+  workspaceFolders?: unknown;
+}
+
+export const getVSCodeBootstrapConfig = (): VSCodeBootstrapConfig | null => {
+  if (typeof window === 'undefined') {
+    return null;
+  }
+  return (window as unknown as { __VSCODE_CONFIG__?: VSCodeBootstrapConfig }).__VSCODE_CONFIG__ ?? null;
+};
+
+export const isVSCodeRuntime = (
+  runtimeApis: RuntimeAPIs | null,
+  bootstrapConfig = getVSCodeBootstrapConfig(),
+): boolean => Boolean(bootstrapConfig || runtimeApis?.runtime?.isVSCode);