diff --git a/src/app.ts b/src/app.ts
index c7f22fa..c5e70ab 100644
--- a/src/app.ts
+++ b/src/app.ts
@@ -27,17 +27,30 @@ export function assertPlatform(platform: string): Platform {
   return platform as Platform;
 }
 
-export function getSelectedApp(platform: Platform) {
+export async function getSelectedApp(
+  platform: Platform,
+): Promise<{ appId: string; appKey: string; platform: Platform }> {
   assertPlatform(platform);
 
-  if (!fs.existsSync('update.json')) {
-    throw new Error(t('appNotSelected', { platform }));
+  let updateInfo: Partial<Record<Platform, { appId: number; appKey: string }>> =
+    {};
+  try {
+    updateInfo = JSON.parse(await fs.promises.readFile('update.json', 'utf8'));
+  } catch (e: any) {
+    if (e.code === 'ENOENT') {
+      throw new Error(t('appNotSelected', { platform }));
+    }
+    throw e;
   }
-  const updateInfo = JSON.parse(fs.readFileSync('update.json', 'utf8'));
-  if (!updateInfo[platform]) {
+  const info = updateInfo[platform];
+  if (!info) {
     throw new Error(t('appNotSelected', { platform }));
   }
-  return updateInfo[platform];
+  return {
+    appId: String(info.appId),
+    appKey: info.appKey,
+    platform,
+  };
 }
 
 export async function listApp(platform: Platform | '' = '') {
@@ -125,10 +138,10 @@ export const appCommands = {
     let updateInfo: Partial<
       Record<Platform, { appId: number; appKey: string }>
     > = {};
-    if (fs.existsSync('update.json')) {
-      try {
-        updateInfo = JSON.parse(fs.readFileSync('update.json', 'utf8'));
-      } catch (e) {
+    try {
+      updateInfo = JSON.parse(await fs.promises.readFile('update.json', 'utf8'));
+    } catch (e: any) {
+      if (e.code !== 'ENOENT') {
         console.error(t('failedToParseUpdateJson'));
         throw e;
       }
@@ -138,7 +151,7 @@ export const appCommands = {
       appId: id,
       appKey,
     };
-    fs.writeFileSync(
+    await fs.promises.writeFile(
       'update.json',
       JSON.stringify(updateInfo, null, 4),
       'utf8',
diff --git a/src/package.ts b/src/package.ts
index be7470d..15a5480 100644
--- a/src/package.ts
+++ b/src/package.ts
@@ -99,7 +99,7 @@ async function uploadNativePackage(
   const { appId: appIdInPkg, appKey: appKeyInPkg } = info;
   const { appId, appKey } = await getSelectedApp(config.platform);
 
-  if (appIdInPkg && appIdInPkg != appId) {
+  if (appIdInPkg && String(appIdInPkg) !== appId) {
     throw new Error(t(config.appIdMismatchKey, { appIdInPkg, appId }));
   }
 
@@ -330,7 +330,7 @@ export const packageCommands = {
   packages: async ({ options }: { options: { platform: Platform } }) => {
     const platform = await getPlatform(options.platform);
     const { appId } = await getSelectedApp(platform);
-    await listPackage(appId);
+    await listPackage(String(appId));
   },
   deletePackage: async ({
     args,
@@ -348,7 +348,7 @@ export const packageCommands = {
 
     if (!appId) {
       const platform = await getPlatform(options.platform);
-      appId = (await getSelectedApp(platform)).appId as string;
+      appId = (await getSelectedApp(platform)).appId;
     }
 
     // If no packageId provided as argument, let user choose from list
diff --git a/src/versions.ts b/src/versions.ts
index 2c3d3eb..53637b2 100644
--- a/src/versions.ts
+++ b/src/versions.ts
@@ -480,12 +480,12 @@ export const versionCommands = {
   versions: async ({ options }: { options: VersionCommandOptions }) => {
     const platform = await getPlatform(options.platform);
     const { appId } = await getSelectedApp(platform);
-    await listVersions(appId);
+    await listVersions(String(appId));
   },
   update: async ({ options }: { options: VersionCommandOptions }) => {
     const platform = await getPlatform(options.platform);
     const appId = options.appId || (await getSelectedApp(platform)).appId;
-    let versionId = options.versionId || (await chooseVersion(appId)).id;
+    let versionId = options.versionId || (await chooseVersion(String(appId))).id;
     if (versionId === 'null') {
       versionId = undefined;
     }
@@ -508,7 +508,7 @@ export const versionCommands = {
       }
     }
 
-    const allPkgs = await getAllPackages(appId);
+    const allPkgs = await getAllPackages(String(appId));
 
     if (!allPkgs) {
       throw new Error(t('noPackagesFound', { appId }));
@@ -558,7 +558,7 @@ export const versionCommands = {
       }
     } else {
       if (!pkgId) {
-        pkgId = (await choosePackage(appId)).id;
+        pkgId = (await choosePackage(String(appId))).id;
       }
 
       if (!pkgId) {
@@ -575,15 +575,15 @@ export const versionCommands = {
     }
 
     await printDepsChangesForPublish({
-      appId,
-      versionId,
+      appId: String(appId),
+      versionId: String(versionId),
       pkgs: pkgsToBind,
       providedVersionDeps: options.versionDeps,
     });
 
     await bindVersionToPackages({
-      appId,
-      versionId,
+      appId: String(appId),
+      versionId: String(versionId),
       pkgs: pkgsToBind,
       rollout,
       dryRun: options.dryRun,
@@ -596,14 +596,14 @@ export const versionCommands = {
   }) => {
     const platform = await getPlatform(options.platform);
     const { appId } = await getSelectedApp(platform);
-    const versionId = options.versionId || (await chooseVersion(appId)).id;
+    const versionId = options.versionId || (await chooseVersion(String(appId))).id;
 
     const updateParams: Record<string, string> = {};
     if (options.name) updateParams.name = options.name;
     if (options.description) updateParams.description = options.description;
     if (options.metaInfo) updateParams.metaInfo = options.metaInfo;
 
-    await put(`/app/${appId}/version/${versionId}`, updateParams);
+    await put(`/app/${String(appId)}/version/${versionId}`, updateParams);
     console.log(t('operationSuccess'));
   },
   deleteVersion: async ({
@@ -619,11 +619,11 @@ export const versionCommands = {
 
     let versionId = options.versionId;
     if (!versionId) {
-      versionId = (await chooseVersion(appId as string)).id;
+      versionId = (await chooseVersion(String(appId))).id;
     }
 
     try {
-      await doDelete(`/app/${appId}/version/${versionId}`);
+      await doDelete(`/app/${String(appId)}/version/${versionId}`);
       console.log(t('deleteVersionSuccess', { versionId }));
     } catch (error: any) {
       throw new Error(