diff --git a/app/src/main/java/com/mntechnique/otpmobileauth/auth/RetrieveAuthTokenTask.java b/app/src/main/java/com/mntechnique/otpmobileauth/auth/RetrieveAuthTokenTask.java
deleted file mode 100644
index fef8826..0000000
--- a/app/src/main/java/com/mntechnique/otpmobileauth/auth/RetrieveAuthTokenTask.java
+++ /dev/null
@@ -1,55 +0,0 @@
-package com.mntechnique.otpmobileauth.auth;
-
-import android.accounts.Account;
-import android.accounts.AccountManager;
-import android.accounts.AccountManagerCallback;
-import android.accounts.AccountManagerFuture;
-import android.content.Context;
-import android.os.AsyncTask;
-import android.os.Bundle;
-import android.util.Log;
-
-import com.mntechnique.otpmobileauth.R;
-
-/**
- * Created by revant on 28/7/17.
- */
-
-public class RetrieveAuthTokenTask extends AsyncTask<String, Void, Void> {
-
-    private Exception exception;
-    private AuthReqCallback callback;
-    private Context context;
-    private String authToken;
-
-    public RetrieveAuthTokenTask(Context context, AuthReqCallback postExecuteCallback) {
-        this.callback = postExecuteCallback;
-        this.context = context;
-    }
-
-    protected Void doInBackground(String... urls) {
-        Account[] accounts = null;
-        final AccountManager am = AccountManager.get(context);
-        accounts = am.getAccountsByType(context.getResources().getString(R.string.package_name));
-        if (accounts.length == 1) {
-            final Account account = accounts[0];
-            am.getAuthToken(account, "Full access", null, true, new AccountManagerCallback<Bundle>() {
-                @Override
-                public void run(AccountManagerFuture<Bundle> future) {
-                    try {
-                        Bundle bundle = future.getResult();
-                        authToken = bundle.getString(AccountManager.KEY_AUTHTOKEN);
-                        callback.onSuccessResponse(authToken);
-                        am.invalidateAuthToken(account.type, authToken);
-                    } catch (Exception e) {
-                        Log.d("error", e.getMessage());
-                        callback.onErrorResponse(e.toString());
-                    }
-                }
-            }, null);
-        } else {
-            Log.d("Accounts", "NOT 1 account found!");
-        }
-        return null;
-    }
-}
diff --git a/app/src/main/java/com/mntechnique/otpmobileauth/auth/RetrieveAuthTokenTask.kt b/app/src/main/java/com/mntechnique/otpmobileauth/auth/RetrieveAuthTokenTask.kt
new file mode 100644
index 0000000..9538d3a
--- /dev/null
+++ b/app/src/main/java/com/mntechnique/otpmobileauth/auth/RetrieveAuthTokenTask.kt
@@ -0,0 +1,45 @@
+package com.mntechnique.otpmobileauth.auth
+
+import android.accounts.Account
+import android.accounts.AccountManager
+import android.accounts.AccountManagerCallback
+import android.accounts.AccountManagerFuture
+import android.content.Context
+import android.os.AsyncTask
+import android.os.Bundle
+import android.util.Log
+
+import com.mntechnique.otpmobileauth.R
+
+/**
+ * Created by revant on 28/7/17.
+ */
+
+class RetrieveAuthTokenTask(private val context: Context, private val callback: AuthReqCallback) : AsyncTask<String, Void, Void>() {
+
+    private val exception: Exception? = null
+    private var authToken: String? = null
+
+    override fun doInBackground(vararg urls: String): Void? {
+        var accounts: Array<Account>? = null
+        val am = AccountManager.get(context)
+        accounts = am.getAccountsByType(context.resources.getString(R.string.package_name))
+        if (accounts!!.size == 1) {
+            val account = accounts[0]
+            am.getAuthToken(account, AccountGeneral.AUTHTOKEN_TYPE_FULL_ACCESS, null, true, { future ->
+                try {
+                    val bundle = future.result
+                    authToken = bundle.getString(AccountManager.KEY_AUTHTOKEN)
+                    callback.onSuccessResponse(authToken!!)
+                    am.invalidateAuthToken(account.type, authToken)
+                } catch (e: Exception) {
+                    Log.d("error", e.message)
+                    callback.onErrorResponse(e.toString())
+                }
+            }, null)
+        } else {
+            Log.d("Accounts", "NOT 1 account found!")
+        }
+        return null
+    }
+}