feat: add Windows ARM64 support with x64-baseline CLI workaround (#2537)

* feat: add Windows ARM64 support with x64-baseline CLI workaround Windows ARM64 native opencode.exe fails with a Bun FFI/TinyCC dlopen error (anomalyco/opencode#19130). As a temporary workaround: - Bundle x64-baseline OpenCode CLI on ARM64 instead of native ARM64 (prepare-opencode-cli.mjs, env-runtime.js) - Disable OpenCode self-upgrade on ARM64 in server, VS Code, and UI (upgrade-capability.js, opencode-upgrade-runtime.ts, useUIStore.ts, OpenCodeCliSettings.tsx, search.ts, SettingsView.tsx, platform.ts) - Add ARM64 Windows cross-compile builds to release and smoke workflows (release.yml, release-desktop-smoke.yml) - Refactor Windows latest.yml to use combine-electron-manifests pattern matching macOS, since two arches now produce per-arch manifests The CI ARM64 build itself is permanent; only the x64-baseline CLI bundling and upgrade disablement are temporary and should be reverted when the upstream issue is resolved. * fix(desktop): select Windows updater by architecture --------- Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>
2026-07-30 20:07:08 +03:00
parent 5792a3d2e2
commit 09f0c64839
18 changed files with 206 additions and 30 deletions
@@ -186,7 +186,7 @@ jobs:

  build-windows-electron:
    if: ${{ inputs.build_windows }}
-    name: Build Windows Electron (x64)
+    name: Build Windows Electron (${{ matrix.arch }})
    # Match the production release workflow. windows-latest currently resolves
    # to a runner with Visual Studio 18, which this Electron/node-gyp stack does
    # not detect correctly.
@@ -198,6 +198,9 @@ jobs:
          - arch: x64
            target: x86_64-pc-windows-msvc
            platform: win32-x64
+          - arch: arm64
+            target: aarch64-pc-windows-msvc
+            platform: win32-arm64
    steps:
      - name: Checkout selected ref
        uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
@@ -249,6 +252,9 @@ jobs:
      - name: Rebuild native modules
        working-directory: packages/electron
        shell: bash
+        env:
+          # Cross-compile for ARM64 target from x64 runner.
+          ELECTRON_BUILDER_ARCH: ${{ matrix.arch }}
        # npmRebuild=false in package.json, so electron-builder won't
        # recompile native deps on its own. Rebuild against the target
        # Electron ABI before packaging, matching the release workflow.
@@ -284,6 +284,9 @@ jobs:
          - arch: x64
            target: x86_64-pc-windows-msvc
            platform: win32-x64
+          - arch: arm64
+            target: aarch64-pc-windows-msvc
+            platform: win32-arm64
    steps:
      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3

@@ -331,6 +334,9 @@ jobs:
      - name: Rebuild native modules
        working-directory: packages/electron
        shell: bash
+        env:
+          # Cross-compile for ARM64 target from x64 runner.
+          ELECTRON_BUILDER_ARCH: ${{ matrix.arch }}
        # npmRebuild=false in package.json, so electron-builder won't
        # recompile native deps on its own — we must rebuild against the
        # target Electron ABI before packaging.
@@ -350,7 +356,6 @@ jobs:
          files: |
            packages/electron/dist/*.exe
            packages/electron/dist/*.blockmap
-            packages/electron/dist/latest.yml
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

@@ -504,7 +509,7 @@ jobs:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

  combine-electron-manifests:
-    needs: [create-release, build-desktop-electron-macos]
+    needs: [create-release, build-desktop-electron-macos, build-desktop-electron-windows]
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@df4cb1c069e1874edd31b4311f1884172cec0e10 # v6.0.3
@@ -514,13 +519,13 @@ jobs:
        with:
          node-version: '22'

-      - name: Download per-arch latest-mac.yml
+      - name: Download per-arch update manifests
        uses: actions/download-artifact@d3f86a106a0bac45b974a628896c90dbdf5c8093 # v4.3.0
        with:
-          pattern: latest-yml-*-apple-darwin
+          pattern: latest-yml-*
          path: artifacts

-      - name: Finalize combined latest-mac.yml
+      - name: Finalize combined manifests
        env:
          LATEST_YML_DIR: ${{ github.workspace }}/artifacts
          GH_REPO: ${{ github.repository }}
@@ -533,6 +538,8 @@ jobs:
          tag_name: v${{ needs.create-release.outputs.version }}
          files: |
            ${{ runner.temp }}/latest-mac.yml
+            ${{ runner.temp }}/latest.yml
+            ${{ runner.temp }}/latest-arm64.yml
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

@@ -76,7 +76,7 @@ macOS builds produce `dmg` and `zip` artifacts. Windows builds produce an NSIS i

 macOS packaging needs Xcode/build tools for notarized builds and icon asset compilation.

-Windows packaging needs NSIS support through `electron-builder`. If no Windows signing env is set, `package.mjs` disables code signing and builds an unsigned installer.
+Windows packaging needs NSIS support through `electron-builder`. If no Windows signing env is set, `package.mjs` disables code signing and builds an unsigned installer. Windows updates use `latest.yml` for x64 and the `latest-arm64.yml` channel for ARM64 so each installation resolves an architecture-matching installer.

 Linux AppImages must be built natively. Set `OPENCHAMBER_TARGET_ARCH=x64` or `OPENCHAMBER_TARGET_ARCH=arm64` when packaging; the build rejects a target that does not match the Linux host. The same target selects the bundled OpenCode CLI, native Electron rebuild, and Electron Builder architecture. Linux identity is stable across architectures: executable `openchamber`, desktop file `openchamber.desktop`, icon `openchamber`, and `StartupWMClass=openchamber`.

@@ -16,6 +16,7 @@ import { resolveManagedOpenCodeCwd } from './opencode-cwd.mjs';
 import { sanitizeRuntimeRequestHeaders } from './runtime-request-headers.mjs';
 import { assertUpdaterCapability } from './updater-capability.mjs';
 import { checkForDesktopUpdate } from './updater-check.mjs';
+import { resolveUpdaterChannel } from './updater-channel.mjs';
 import { resolveUpdaterFeed } from './updater-feed.mjs';
 import {
  buildLinuxInstalledApps,
@@ -2927,10 +2928,17 @@ const setupAutoUpdater = () => {
  const testBuild = typeof __OPENCHAMBER_UPDATER_E2E_BUILD__ !== 'undefined'
    && __OPENCHAMBER_UPDATER_E2E_BUILD__ === true;
  const feed = resolveUpdaterFeed({ testBuild });
+  const updaterChannel = feed.provider === 'github'
+    ? resolveUpdaterChannel({ platform: process.platform, architecture: process.arch })
+    : null;
+  if (updaterChannel) {
+    autoUpdater.channel = updaterChannel;
+  }
  autoUpdater.setFeedURL(feed);
  log.info('[electron] updater feed configured', {
    provider: feed.provider,
    target: feed.provider === 'github' ? `${feed.owner}/${feed.repo}` : feed.url,
+    channel: updaterChannel || 'latest',
  });

  autoUpdater.on('download-progress', (progress) => {
@@ -40,7 +40,7 @@
    "generate:macos-icon": "node ./scripts/generate-macos-icon-assets.cjs",
    "rebuild:native": "node ./scripts/rebuild-native.mjs",
    "test:architecture": "node --test ./scripts/target-architecture.test.mjs ./scripts/verify-linux-appimage.test.mjs ./scripts/verify-update-manifest.test.mjs",
-    "test:updater": "node --test ./updater-capability.test.mjs ./updater-check.test.mjs ./updater-feed.test.mjs ./scripts/updater-e2e-fixture.test.mjs",
+    "test:updater": "node --test ./updater-capability.test.mjs ./updater-channel.test.mjs ./updater-check.test.mjs ./updater-feed.test.mjs ./scripts/finalize-latest-yml.test.mjs ./scripts/updater-e2e-fixture.test.mjs",
    "test:linux-desktop": "node --test ./linux-autostart.test.mjs && node ./scripts/smoke-linux-app-discovery.mjs && node ./scripts/smoke-path-open-utils.mjs",
    "updater:e2e:fixture": "node ./scripts/updater-e2e-fixture.mjs",
    "verify:update-manifest": "node ./scripts/verify-update-manifest.mjs",
@@ -76,14 +76,11 @@ const output = {};

 const winX64 = await read('latest-yml-x86_64-pc-windows-msvc', 'latest.yml');
 const winArm64 = await read('latest-yml-aarch64-pc-windows-msvc', 'latest.yml');
-if (winX64 || winArm64) {
-  const base = winArm64 || winX64;
-  output['latest.yml'] = serialize({
-    version: base.version,
-    files: [...(winArm64?.files || []), ...(winX64?.files || [])],
-    releaseDate: base.releaseDate,
-  });
+if (!winX64 || !winArm64) {
+  throw new Error('Both x64 and arm64 Windows update manifests are required');
 }
+output['latest.yml'] = serialize(winX64);
+output['latest-arm64.yml'] = serialize(winArm64);

 const macX64 = await read('latest-yml-x86_64-apple-darwin', 'latest-mac.yml');
 const macArm64 = await read('latest-yml-aarch64-apple-darwin', 'latest-mac.yml');
@@ -0,0 +1,63 @@
+import assert from 'node:assert/strict';
+import { execFileSync, spawnSync } from 'node:child_process';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+import { fileURLToPath } from 'node:url';
+
+const script = fileURLToPath(new URL('./finalize-latest-yml.mjs', import.meta.url));
+
+const manifest = (architecture) => `version: 1.2.3
+files:
+  - url: OpenChamber-1.2.3-win-${architecture}.exe
+    sha512: ${architecture}-checksum
+    size: 123
+releaseDate: '2026-07-30T00:00:00.000Z'
+`;
+
+const createFixture = ({ includeArm64 = true } = {}) => {
+  const root = fs.mkdtempSync(path.join(os.tmpdir(), 'openchamber-latest-yml-'));
+  const artifacts = path.join(root, 'artifacts');
+  const output = path.join(root, 'output');
+  fs.mkdirSync(path.join(artifacts, 'latest-yml-x86_64-pc-windows-msvc'), { recursive: true });
+  fs.writeFileSync(path.join(artifacts, 'latest-yml-x86_64-pc-windows-msvc', 'latest.yml'), manifest('x64'));
+  if (includeArm64) {
+    fs.mkdirSync(path.join(artifacts, 'latest-yml-aarch64-pc-windows-msvc'), { recursive: true });
+    fs.writeFileSync(path.join(artifacts, 'latest-yml-aarch64-pc-windows-msvc', 'latest.yml'), manifest('arm64'));
+  }
+  fs.mkdirSync(output);
+  return { root, artifacts, output };
+};
+
+const environment = ({ artifacts, output }) => ({
+  ...process.env,
+  LATEST_YML_DIR: artifacts,
+  RUNNER_TEMP: output,
+  GH_REPO: 'openchamber/openchamber',
+  OPENCHAMBER_VERSION: '1.2.3',
+});
+
+test('writes separate x64 and ARM64 Windows update channels', (context) => {
+  const fixture = createFixture();
+  context.after(() => fs.rmSync(fixture.root, { recursive: true, force: true }));
+
+  execFileSync(process.execPath, [script], { env: environment(fixture) });
+
+  const x64 = fs.readFileSync(path.join(fixture.output, 'latest.yml'), 'utf8');
+  const arm64 = fs.readFileSync(path.join(fixture.output, 'latest-arm64.yml'), 'utf8');
+  assert.match(x64, /win-x64\.exe/);
+  assert.doesNotMatch(x64, /win-arm64\.exe/);
+  assert.match(arm64, /win-arm64\.exe/);
+  assert.doesNotMatch(arm64, /win-x64\.exe/);
+});
+
+test('fails instead of publishing an incomplete Windows channel set', (context) => {
+  const fixture = createFixture({ includeArm64: false });
+  context.after(() => fs.rmSync(fixture.root, { recursive: true, force: true }));
+
+  const result = spawnSync(process.execPath, [script], { env: environment(fixture), encoding: 'utf8' });
+
+  assert.notEqual(result.status, 0);
+  assert.match(result.stderr, /Both x64 and arm64 Windows update manifests are required/);
+});
@@ -47,7 +47,17 @@ const artifactForPlatform = (platform, targetArchitecture) => {
    if (arch === 'x64') return { name: 'opencode-darwin-x64-baseline.zip', binary: 'opencode' };
  }
  if (platform === 'win32') {
-    if (arch === 'arm64') return { name: 'opencode-windows-arm64.zip', binary: 'opencode.exe' };
+    // TEMPORARY WORKAROUND — Windows ARM64: native opencode.exe fails with a Bun
+    // FFI/TinyCC dlopen error (https://github.com/anomalyco/opencode/issues/19130).
+    // Bundle x64-baseline instead (runs under x64 emulation); OpenCode self-upgrade
+    // is disabled elsewhere so it can't overwrite with the broken ARM64 build.
+    // Remove this block and restore the original below when the upstream issue
+    // is resolved.
+    // --- ORIGINAL (restore when ARM64 is fixed) ---
+    // if (arch === 'arm64') return { name: 'opencode-windows-arm64.zip', binary: 'opencode.exe' };
+    // if (arch === 'x64') return { name: 'opencode-windows-x64-baseline.zip', binary: 'opencode.exe' };
+    // --- END ORIGINAL ---
+    if (arch === 'arm64') return { name: 'opencode-windows-x64-baseline.zip', binary: 'opencode.exe' };
    if (arch === 'x64') return { name: 'opencode-windows-x64-baseline.zip', binary: 'opencode.exe' };
  }
  if (platform === 'linux') {
@@ -0,0 +1,3 @@
+export const resolveUpdaterChannel = ({ platform, architecture }) => (
+  platform === 'win32' && architecture === 'arm64' ? 'latest-arm64' : null
+);
@@ -0,0 +1,13 @@
+import assert from 'node:assert/strict';
+import test from 'node:test';
+import { resolveUpdaterChannel } from './updater-channel.mjs';
+
+test('uses an architecture-specific Windows ARM64 update channel', () => {
+  assert.equal(resolveUpdaterChannel({ platform: 'win32', architecture: 'arm64' }), 'latest-arm64');
+});
+
+test('keeps the default channel for other desktop targets', () => {
+  assert.equal(resolveUpdaterChannel({ platform: 'win32', architecture: 'x64' }), null);
+  assert.equal(resolveUpdaterChannel({ platform: 'darwin', architecture: 'arm64' }), null);
+  assert.equal(resolveUpdaterChannel({ platform: 'linux', architecture: 'arm64' }), null);
+});
@@ -16,6 +16,7 @@ import { reloadOpenCodeConfiguration } from '@/stores/useAgentsStore';
 import { useUIStore } from '@/stores/useUIStore';
 import { useI18n } from '@/lib/i18n';
 import { runtimeFetch } from '@/lib/runtime-fetch';
+import { isWindowsArm64 } from '@/lib/platform';

 export const OpenCodeCliSettings: React.FC = () => {
  const { t } = useI18n();
@@ -151,13 +152,15 @@ export const OpenCodeCliSettings: React.FC = () => {
        </SettingsFieldRow>

        <SettingsInset className={SETTINGS_OPTION_STACK_CLASS}>
-          <SettingsCheckboxRow
-            settingsItem="sessions.opencode-update-notifications"
-            checked={showOpenCodeUpdateNotifications}
-            onChange={handleShowUpdateNotificationsChange}
-            label={t('settings.openchamber.opencodeCli.field.showUpdateNotifications')}
-            ariaLabel={t('settings.openchamber.opencodeCli.field.showUpdateNotificationsAria')}
-          />
+          {!isWindowsArm64() && (
+            <SettingsCheckboxRow
+              settingsItem="sessions.opencode-update-notifications"
+              checked={showOpenCodeUpdateNotifications}
+              onChange={handleShowUpdateNotificationsChange}
+              label={t('settings.openchamber.opencodeCli.field.showUpdateNotifications')}
+              ariaLabel={t('settings.openchamber.opencodeCli.field.showUpdateNotificationsAria')}
+            />
+          )}

          <SettingsCheckboxRow
            settingsItem="sessions.agent-control-tool"
@@ -43,6 +43,7 @@ import {
 } from '@/components/sections/shared/SettingsSection';
 import { useDeviceInfo } from '@/lib/device';
 import { isDesktopLocalOriginActive, isDesktopShell, isVSCodeRuntime, isWebRuntime } from '@/lib/desktop';
+import { isWindowsArm64 as isWindowsArm64Platform } from '@/lib/platform';
 import { useI18n } from '@/lib/i18n';
 import { Icon } from "@/components/icon/Icon";
 import type { IconName } from "@/components/icon/icons";
@@ -278,6 +279,7 @@ export const SettingsView: React.FC<SettingsViewProps> = ({ onClose, forceMobile
    return isDesktopShell() && typeof window !== 'undefined'
      && (window as unknown as { __OPENCHAMBER_PLATFORM__?: string }).__OPENCHAMBER_PLATFORM__ === 'linux';
  }, []);
+  const isWindowsArm64 = React.useMemo(() => isWindowsArm64Platform(), []);

  // keep platform check available for future window chrome tweaks

@@ -421,12 +423,12 @@ export const SettingsView: React.FC<SettingsViewProps> = ({ onClose, forceMobile
  const settingsSearchResults = React.useMemo(() => {
    return buildSettingsSearchResults({
      query: settingsSearchQuery,
-      runtimeCtx: { ...runtimeCtx, isDesktopLocalOrigin, isMac, isWindows, isLinux },
+      runtimeCtx: { ...runtimeCtx, isDesktopLocalOrigin, isMac, isWindows, isLinux, isWindowsArm64 },
      visiblePageSlugs,
      t,
      getPageTitle,
    });
-  }, [getPageTitle, isDesktopLocalOrigin, isMac, isWindows, isLinux, runtimeCtx, settingsSearchQuery, t, visiblePageSlugs]);
+  }, [getPageTitle, isWindowsArm64, isDesktopLocalOrigin, isMac, isWindows, isLinux, runtimeCtx, settingsSearchQuery, t, visiblePageSlugs]);

  const prepareSettingsSearchTarget = React.useCallback((result: SettingsSearchResult): string => {
    if (result.id.startsWith('agents.')) {
@@ -7,6 +7,39 @@ export const isCapacitorApp = (): boolean => {
  return capacitor?.isNativePlatform?.() === true || window.location.protocol === 'capacitor:';
 };

+// TEMPORARY WORKAROUND — Windows ARM64: native opencode.exe fails with a Bun
+// FFI/TinyCC dlopen error (https://github.com/anomalyco/opencode/issues/19130).
+// Suppress OpenCode update UI on ARM64 so it can't self-upgrade to the broken
+// ARM64 build. Remove this helper and its call sites when resolved upstream.
+export const isWindowsArm64 = (): boolean => {
+  if (typeof window === 'undefined') return false;
+
+  const electronArch = window.__OPENCHAMBER_ELECTRON__?.arch?.toLowerCase?.();
+  if (electronArch === 'arm64' || electronArch === 'aarch64') {
+    const platform = (navigator.platform || '').toLowerCase();
+    return platform.includes('win');
+  }
+
+  const vscodeArch = (window as { __VSCODE_CONFIG__?: { arch?: string } }).__VSCODE_CONFIG__?.arch?.toLowerCase?.();
+  if (vscodeArch === 'arm64' || vscodeArch === 'aarch64') {
+    const platform = (navigator.platform || '').toLowerCase();
+    return platform.includes('win');
+  }
+
+  const nav = (navigator as Navigator & { userAgentData?: { architecture?: string; platform?: string } }).userAgentData;
+  if (nav?.architecture?.toLowerCase?.() === 'arm64' || nav?.architecture?.toLowerCase?.() === 'aarch64') {
+    const platform = (nav.platform || navigator.platform || '').toLowerCase();
+    return platform.includes('win');
+  }
+
+  const ua = navigator.userAgent.toLowerCase();
+  if ((ua.includes('aarch64') || ua.includes('arm64') || ua.includes('armv')) && ua.includes('windows')) {
+    return true;
+  }
+
+  return false;
+};
+
 /**
 * True when running inside the native Capacitor shell on an iPad.
 * Capacitor reports 'ios' for both iPhone and iPad; iPadOS WKWebView
@@ -26,6 +26,8 @@ interface SettingsSearchAvailabilityContext extends SettingsRuntimeContext {
  isWindows: boolean;
  // Linux desktop shell — for controls that only render on linux.
  isLinux: boolean;
+  // Windows ARM64 — temporary workaround gate (see opencode#19130).
+  isWindowsArm64: boolean;
 }

 const SETTINGS_SEARCH_ITEMS: readonly SettingsSearchItem[] = [
@@ -470,7 +472,7 @@ const SETTINGS_SEARCH_ITEMS: readonly SettingsSearchItem[] = [
    page: 'general',
    titleKey: 'settings.openchamber.opencodeCli.field.showUpdateNotifications',
    keywords: ['opencode', 'cli', 'updates'],
-    isAvailable: (ctx) => !ctx.isVSCode,
+    isAvailable: (ctx) => !ctx.isVSCode && !ctx.isWindowsArm64,
  },
  {
    id: 'sessions.agent-control-tool',
@@ -10,6 +10,7 @@ import { getStoredMobileKeyboardMode, type MobileKeyboardMode } from '@/lib/mobi
 import { getRuntimeKey } from '@/lib/runtime-switch';
 import type { TerminalShell } from '@/lib/api/types';
 import { useFilesViewTabsStore } from './useFilesViewTabsStore';
+import { isWindowsArm64 } from '@/lib/platform';

 export type MainTab = 'chat' | 'plan' | 'git' | 'diff' | 'terminal' | 'files' | 'context' | 'diagram';
 export type PendingDiffScope = 'working' | 'staged' | 'turn';
@@ -999,7 +1000,7 @@ export const useUIStore = create<UIStore>()(

        showTerminalQuickKeysOnDesktop: false,
        persistChatDraft: true,
-        showOpenCodeUpdateNotifications: true,
+        showOpenCodeUpdateNotifications: !isWindowsArm64(),
        agentControlToolEnabled: true,
        inputSpellcheckEnabled: false,
        wideChatLayoutEnabled: false,
@@ -1,7 +1,7 @@
 type UpgradeCapability = {
  supported: boolean;
-  manager: 'opencode' | 'external' | null;
-  reason: 'external' | 'unavailable' | null;
+  manager: 'opencode' | 'external' | 'openchamber' | null;
+  reason: 'external' | 'unavailable' | 'windows-arm64-workaround' | null;
 };

 export type OpenCodeUpgradeManager = {
@@ -15,6 +15,12 @@ type UpgradeResult = { status: number; body: Record<string, unknown> };

 let openCodeUpgradePromise: Promise<UpgradeResult> | null = null;

+// TEMPORARY WORKAROUND — Windows ARM64: native opencode.exe fails with a Bun
+// FFI/TinyCC dlopen error (https://github.com/anomalyco/opencode/issues/19130).
+// Disable OpenCode self-upgrade on ARM64 so it can't overwrite the working x64
+// binary with the broken ARM64 build. Remove when the upstream issue is resolved.
+const isWindowsArm64 = (): boolean => process.platform === 'win32' && process.arch === 'arm64';
+
 const parseVersion = (value: unknown): { parts: number[]; prerelease: boolean } => {
  const normalized = String(value || '').replace(/^v/, '').split('+')[0];
  const prereleaseIndex = normalized.indexOf('-');
@@ -39,6 +45,7 @@ const compareVersions = (left: unknown, right: unknown): number => {
 };

 const getCapability = (manager?: OpenCodeUpgradeManager): UpgradeCapability => {
+  if (isWindowsArm64()) return { supported: false, manager: 'openchamber', reason: 'windows-arm64-workaround' };
  if (!manager) return { supported: false, manager: null, reason: 'unavailable' };
  if (manager.getDebugInfo().mode !== 'managed') return { supported: false, manager: 'external', reason: 'external' };
  if (!manager.getApiUrl()) return { supported: false, manager: null, reason: 'unavailable' };
@@ -664,8 +664,15 @@ export const createOpenCodeEnvRuntime = (deps) => {
  };

  const getWindowsNativeOpencodePackageNames = () => {
+    // TEMPORARY WORKAROUND — Windows ARM64: native opencode.exe fails with a Bun
+    // FFI/TinyCC dlopen error (https://github.com/anomalyco/opencode/issues/19130).
+    // prepare-opencode-cli.mjs bundles x64-baseline instead; match that here so
+    // the runtime resolver looks for the same x64-baseline package. Restore the
+    // arm64 branch below when the upstream issue is resolved.
    if (process.arch === 'arm64') {
-      return ['opencode-windows-arm64'];
+      // --- ORIGINAL (restore when ARM64 is fixed) ---
+      // return ['opencode-windows-arm64'];
+      return ['opencode-windows-x64-baseline', 'opencode-windows-x64'];
    }
    if (process.arch === 'x64') {
      // Prefer the baseline build when bypassing package-manager wrappers so the
@@ -1,9 +1,23 @@
+// TEMPORARY WORKAROUND — Windows ARM64: native opencode.exe fails with a Bun
+// FFI/TinyCC dlopen error (https://github.com/anomalyco/opencode/issues/19130).
+// Disable OpenCode self-upgrade on ARM64 so it can't overwrite the working x64
+// binary with the broken ARM64 build. Remove when the upstream issue is resolved.
+const isWindowsArm64 = () => process.platform === 'win32' && process.arch === 'arm64';
+
 export const resolveOpenCodeUpgradeCapability = ({
  isExternal,
  hasManagedProcess,
  activeBinary,
  isBundledBinary,
 }) => {
+  if (isWindowsArm64()) {
+    return {
+      supported: false,
+      manager: 'openchamber',
+      reason: 'windows-arm64-workaround',
+    };
+  }
+
  if (isExternal) {
    return {
      supported: false,