diff --git a/Monobank.Client/Extensions/Int64Extensions.cs b/Monobank.Client/Extensions/Int64Extensions.cs
index 3da9f01..867a0f2 100644
--- a/Monobank.Client/Extensions/Int64Extensions.cs
+++ b/Monobank.Client/Extensions/Int64Extensions.cs
@@ -22,5 +22,10 @@ public static double AsMoney(this long input)
             var parsed = double.TryParse(balance, out var parsedValue);
             return parsed ? parsedValue : 0;
         }
+
+        public static double AsMoney(this long? input)
+        {
+            return input?.AsMoney() ?? 0;
+        }
     }
 }
diff --git a/Monobank.Client/Models/Jar.cs b/Monobank.Client/Models/Jar.cs
index 104d882..8da984f 100644
--- a/Monobank.Client/Models/Jar.cs
+++ b/Monobank.Client/Models/Jar.cs
@@ -25,7 +25,7 @@ public class Jar
         public long Balance { get; set; }
 
         [JsonPropertyName("goal")]
-        public long Goal { get; set; }
+        public long? Goal { get; set; }
 
         #region Custom properties
 
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..8bcd082
--- /dev/null
+++ b/README.md
@@ -0,0 +1,22 @@
+# MonobankClient [<img src="https://img.shields.io/nuget/dt/MonobankClient?style=for-the-badge">](https://www.nuget.org/packages/MonobankClient/)<br>
+[<img src="https://img.shields.io/github/v/release/TheGarmr/monobank-client?label=Latest%20GitHub%20release&style=for-the-badge">](https://github.com/TheGarmr/monobank-client/releases/latest)
+[<img src="https://img.shields.io/nuget/v/MonobankClient?label=Latest%20Nuget%20version&style=for-the-badge">](https://www.nuget.org/packages/MonobankClient/)<br>
+
+### This application helps to integrate [Monobank open API](https://api.monobank.ua)(client) to your application.
+### Full API documentation can be found here: [Monobank open API](https://api.monobank.ua/docs/)
+
+### Functionality
+  * [Obtaining exchange rates](https://api.monobank.ua/docs/#tag/Publichni-dani/paths/~1bank~1currency/get)
+  * [Information about the client](https://api.monobank.ua/docs/#tag/Kliyentski-personalni-dani/paths/~1personal~1client-info/get)
+  * [Set up WebHook](https://api.monobank.ua/docs/#tag/Kliyentski-personalni-dani/paths/~1personal~1webhook/post)
+  * [Extract transactions](https://api.monobank.ua/docs/#tag/Kliyentski-personalni-dani/paths/~1personal~1statement~1{account}~1{from}~1{to}/get)
+
+### API limitations:
+  * You can receive information about a client once per a minute
+  * Information about currencies refreshes once per 5 minutes
+
+### Quickstart:
+  * Go to your [personal profile](https://api.monobank.ua/)
+  * Create a token
+  * Install the package from [Nuget.org](https://www.nuget.org/packages/MonobankClient/)
+  * Add MonobankClient to DI via calling method `services.AddMonobankClient();`