diff --git a/.github/workflows/publish.yml b/.github/workflows/publish.yml
index 9a708a52..d7a7d52c 100644
--- a/.github/workflows/publish.yml
+++ b/.github/workflows/publish.yml
@@ -25,12 +25,22 @@ jobs:
           repository: 'microsoft/monaco-editor'
           path: './monaco-editor'
 
+      - name: Compute state
+        id: state
+        run: node ./monaco-editor/.github/workflows/publish/computeState.js "${{github.event_name}}" "${{github.event.inputs.nightly}}"
+        # outputs: version, vscode_branch, skip_monaco_editor_core, skip_monaco_editor
+
       - name: (vscode) checkout
         uses: actions/checkout@v2
         with:
           repository: 'microsoft/vscode'
+          ref: ${{ steps.state.outputs.vscode_branch }}"
           path: './vscode'
 
+      # TODO
+      - name: Early stop
+        run: exit 1
+
       - name: (vscode-loc) checkout
         uses: actions/checkout@v2
         with:
diff --git a/.github/workflows/publish/computeState.js b/.github/workflows/publish/computeState.js
new file mode 100644
index 00000000..7c450105
--- /dev/null
+++ b/.github/workflows/publish/computeState.js
@@ -0,0 +1,96 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+//@ts-check
+
+const fs = require('fs');
+const cp = require('child_process');
+const packageJson = require('../../../package.json');
+
+if (process.argv.length !== 4) {
+	console.error(`usage: node computeState.js <"workflow_dispatch"|"schedule"> <"true"|"false">`);
+	process.exit(1);
+}
+
+const EVENT_NAME = /** @type {'workflow_dispatch'|'schedule'} */ (process.argv[2]);
+const STR_NIGHTLY = /** @type {'true'|'false'|''} */ (process.argv[3]);
+
+if (!/^((workflow_dispatch)|(schedule))$/.test(EVENT_NAME)) {
+	console.error(`usage: node computeState.js <"workflow_dispatch"|"schedule"> <"true"|"false">`);
+	process.exit(2);
+}
+
+if (!/^((true)|(false)|())$/.test(STR_NIGHTLY)) {
+	console.error(`usage: node computeState.js <"workflow_dispatch"|"schedule"> <"true"|"false">`);
+	process.exit(3);
+}
+
+const NIGHTLY = EVENT_NAME === 'schedule' || STR_NIGHTLY === 'true';
+
+const latestMonacoEditorVersion = npmGetLatestVersion('monaco-editor');
+const version = (() => {
+	if (NIGHTLY) {
+		const pieces = latestMonacoEditorVersion.split('.');
+		const minor = parseInt(pieces[1], 10);
+		const date = new Date();
+		const yyyy = date.getUTCFullYear();
+		const mm = String(date.getUTCMonth() + 1).padStart(2, '0');
+		const dd = String(date.getUTCDate()).padStart(2, '0');
+		return `0.${minor + 1}.0-dev.${yyyy}${mm}${dd}`;
+	} else {
+		return packageJson.version;
+	}
+})();
+
+const vscodeBranch = (() => {
+	if (NIGHTLY) {
+		return 'main';
+	} else {
+		return packageJson.vscode;
+	}
+})();
+
+const skipMonacoEditorCore = (() => {
+	return /** @type {'true'|'false'} */ (String(npmExists('monaco-editor-core', version)));
+})();
+
+const skipMonacoEditor = (() => {
+	return /** @type {'true'|'false'} */ (String(npmExists('monaco-editor-core', version)));
+})();
+
+console.log(`
+::set-output name=version::${version}
+::set-output name=vscode_branch::${vscodeBranch}
+::set-output name=skip_monaco_editor_core::${skipMonacoEditorCore}
+::set-output name=skip_monaco_editor::${skipMonacoEditor}
+`);
+
+/**
+ * @param {string} packageName
+ * @returns {string}
+ */
+function npmGetLatestVersion(packageName) {
+	const output = cp.execSync(`npm show ${packageName} version`).toString();
+	const version = output.split(/\r\n|\r|\n/g)[0];
+	if (!/^0\.(\d+)\.(\d+)$/.test(version)) {
+		console.error(`version ${version} does not match 0.x.y`);
+		process.exit(1);
+	}
+	return version;
+}
+
+/**
+ * @param {string} packageName
+ * @param {string} version
+ * @returns {boolean}
+ */
+function npmExists(packageName, version) {
+	const output = cp.execSync(`npm show ${packageName}@${version} version`).toString();
+	const result = output.split(/\r\n|\r|\n/g)[0];
+	if (result.trim().length === 0) {
+		return false;
+	}
+	return true;
+}
diff --git a/.github/workflows/publish/setNightlyVersion.js b/.github/workflows/publish/setNightlyVersion.js
index 42473ef8..eefa0e3e 100644
--- a/.github/workflows/publish/setNightlyVersion.js
+++ b/.github/workflows/publish/setNightlyVersion.js
@@ -9,7 +9,7 @@ const fs = require('fs');
 const cp = require('child_process');
 
 if (process.argv.length !== 3) {
-	console.error(`usage: node updateVersion.js <PATH_TO_PACKAGE_JSON_FILE>`);
+	console.error(`usage: node setNightlyVersion.js <PATH_TO_PACKAGE_JSON_FILE>`);
 	process.exit(1);
 }