diff --git a/packages/frontend/package.json b/packages/frontend/package.json
index 3f634a0d80..b6906e130a 100644
--- a/packages/frontend/package.json
+++ b/packages/frontend/package.json
@@ -25,7 +25,7 @@
 		"@rollup/plugin-replace": "6.0.3",
 		"@rollup/pluginutils": "5.3.0",
 		"@sentry/vue": "10.26.0",
-		"@syuilo/aiscript": "1.1.2",
+		"@syuilo/aiscript": "1.2.0",
 		"@syuilo/aiscript-0-19-0": "npm:@syuilo/aiscript@^0.19.0",
 		"@twemoji/parser": "16.0.0",
 		"@vitejs/plugin-vue": "6.0.2",
diff --git a/packages/frontend/src/aiscript/api.ts b/packages/frontend/src/aiscript/api.ts
index dc84925375..3a476787fe 100644
--- a/packages/frontend/src/aiscript/api.ts
+++ b/packages/frontend/src/aiscript/api.ts
@@ -40,29 +40,77 @@ export function createAiScriptEnv(opts: { storageKey: string, token?: string })
 		CUSTOM_EMOJIS: utils.jsToVal(customEmojis.value),
 		LOCALE: values.STR(lang),
 		SERVER_URL: values.STR(url),
-		'Mk:dialog': values.FN_NATIVE(async ([title, text, type]) => {
-			utils.assertString(title);
-			utils.assertString(text);
-			if (type != null) {
-				assertStringAndIsIn(type, DIALOG_TYPES);
+		'Mk:dialog': values.FN_NATIVE(async ([_title, _text, _type]) => {
+			let title: string | undefined = undefined;
+			let text: string | undefined = undefined;
+			let type: typeof DIALOG_TYPES[number] = 'info';
+
+			if (_title != null) {
+				if (utils.isString(_title)) {
+					title = _title.value;
+				} else {
+					utils.assertNull(_title);
+				}
 			}
+
+			if (_text != null) {
+				if (utils.isString(_text)) {
+					text = _text.value;
+				} else {
+					utils.assertNull(_text);
+				}
+			}
+
+			if (_type != null) {
+				if (utils.isString(_type)) {
+					assertStringAndIsIn(_type, DIALOG_TYPES);
+					type = _type.value;
+				} else {
+					utils.assertNull(_type);
+				}
+			}
+
 			await os.alert({
-				type: type ? type.value : 'info',
-				title: title.value,
-				text: text.value,
+				type,
+				title,
+				text,
 			});
 			return values.NULL;
 		}),
-		'Mk:confirm': values.FN_NATIVE(async ([title, text, type]) => {
-			utils.assertString(title);
-			utils.assertString(text);
-			if (type != null) {
-				assertStringAndIsIn(type, DIALOG_TYPES);
+		'Mk:confirm': values.FN_NATIVE(async ([_title, _text, _type]) => {
+			let title: string | undefined = undefined;
+			let text: string | undefined = undefined;
+			let type: typeof DIALOG_TYPES[number] = 'question';
+
+			if (_title != null) {
+				if (utils.isString(_title)) {
+					title = _title.value;
+				} else {
+					utils.assertNull(_title);
+				}
 			}
+
+			if (_text != null) {
+				if (utils.isString(_text)) {
+					text = _text.value;
+				} else {
+					utils.assertNull(_text);
+				}
+			}
+
+			if (_type != null) {
+				if (utils.isString(_type)) {
+					assertStringAndIsIn(_type, DIALOG_TYPES);
+					type = _type.value;
+				} else {
+					utils.assertNull(_type);
+				}
+			}
+
 			const confirm = await os.confirm({
-				type: type ? type.value : 'question',
-				title: title.value,
-				text: text.value,
+				type,
+				title,
+				text,
 			});
 			return confirm.canceled ? values.FALSE : values.TRUE;
 		}),
@@ -76,15 +124,23 @@ export function createAiScriptEnv(opts: { storageKey: string, token?: string })
 			if (ep.value.includes('://') || ep.value.includes('..')) {
 				throw new errors.AiScriptRuntimeError('invalid endpoint');
 			}
-			if (token) {
+
+			let actualToken: string | null = null;
+			if (token != null && !utils.isNull(token)) {
 				utils.assertString(token);
 				// バグがあればundefinedもあり得るため念のため
-				if (typeof token.value !== 'string') throw new Error('invalid token');
+				if (typeof token.value !== 'string') throw new errors.AiScriptRuntimeError('invalid token');
+				actualToken = token.value;
 			}
-			const actualToken: string | null = token?.value ?? opts.token ?? null;
+
+			if (actualToken == null) {
+				actualToken = opts.token ?? null;
+			}
+
 			if (param == null) {
 				throw new errors.AiScriptRuntimeError('expected param');
 			}
+
 			utils.assertObject(param);
 			return misskeyApi(ep.value as keyof Misskey.Endpoints, utils.valToJs(param) as object, actualToken).then(res => {
 				return utils.jsToVal(res);
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index bfc71f5256..519ea8a7e4 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -729,8 +729,8 @@ importers:
         specifier: 10.26.0
         version: 10.26.0(vue@3.5.24(typescript@5.9.3))
       '@syuilo/aiscript':
-        specifier: 1.1.2
-        version: 1.1.2
+        specifier: 1.2.0
+        version: 1.2.0
       '@syuilo/aiscript-0-19-0':
         specifier: npm:@syuilo/aiscript@^0.19.0
         version: '@syuilo/aiscript@0.19.0'
@@ -4459,8 +4459,8 @@ packages:
   '@syuilo/aiscript@0.19.0':
     resolution: {integrity: sha512-ZWG4s1m6RrFjE7NeIMaxFz769YO1jW5ReTrOROrEO4IHheOrjxxJ/Ffe2TUNqX9/XxDloMwfWplKhfSzx8LGMA==}
 
-  '@syuilo/aiscript@1.1.2':
-    resolution: {integrity: sha512-cijsHTiMjeECocElyjRIcWMPGDhZIX3YfCOyzI6AZM8ajxRQ2hSqJwEh9pDr4mVTml9kLMHWDHmgfHkTHRJ1sg==}
+  '@syuilo/aiscript@1.2.0':
+    resolution: {integrity: sha512-3MkKfqDftqHyouINgHEIHnoTVWEeL0L1o7Y7Y9d8qb5h5vZKphzH/KVG3R2iI6CHtmO1mWHHJx5A499f80H9FA==}
 
   '@szmarczak/http-timer@5.0.1':
     resolution: {integrity: sha512-+PmQX0PiAYPMeVYe237LJAYvOMYW1j2rH5YROyS3b4CTVJum34HfRvKvAzozHAQG0TnHNdUfY9nCeUyRAs//cw==}
@@ -14858,7 +14858,7 @@ snapshots:
       stringz: 2.1.0
       uuid: 9.0.1
 
-  '@syuilo/aiscript@1.1.2':
+  '@syuilo/aiscript@1.2.0':
     dependencies:
       seedrandom: 3.0.5
       stringz: 2.1.0
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index 8757f8dc26..8f7fdf13c8 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -32,3 +32,4 @@ onlyBuiltDependencies:
 ignorePatchFailures: false
 minimumReleaseAge: 10080 # delay 7days to mitigate supply-chain attack
 minimumReleaseAgeExclude:
+  - '@syuilo/aiscript'