diff --git a/src/OnePeek.Api/IOnePeekApi.cs b/src/OnePeek.Api/IOnePeekApi.cs
new file mode 100644
index 0000000..1e5ba16
--- /dev/null
+++ b/src/OnePeek.Api/IOnePeekApi.cs
@@ -0,0 +1,21 @@
+using OnePeek.Entities;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace OnePeek.Api
+{
+  public interface IOnePeekApi
+  {
+    Task<Stream> GetImageAsStream(string urn, StoreImageType imageType = StoreImageType.None);
+    Uri GetImageUri(string urn, StoreImageType imageType = StoreImageType.None);
+    Task<AppMetadata> GetMetadata(string appId, StoreType store, StoreCultureType storeCulture);
+    Task<IEnumerable<AppMetadata>> GetMetadataForAllCultures(string appId, StoreType store, CancellationToken ct, IProgress<DownloadProgressChangedEventArgs> progress);
+    Task<AppRating> GetRating(string appId, StoreType store, StoreCultureType storeCulture);
+    Task<IEnumerable<AppRating>> GetRatingsForAllCultures(string appId, StoreType store, CancellationToken ct, IProgress<DownloadProgressChangedEventArgs> progress);
+    Task<AppReviews> GetReviews(string appId, StoreType store, StoreCultureType storeCulture, StoreReviewSorting sorting, string prevPageMarkerId = null, string nextPageMarkerId = null);
+    Task<StoreSearchResults> Search(string searchTerm, StoreType store, StoreCultureType storeCulture);
+  }
+}
diff --git a/src/OnePeek.Api/OnePeekApi.cs b/src/OnePeek.Api/OnePeekApi.cs
index eb1379e..1b048e2 100644
--- a/src/OnePeek.Api/OnePeekApi.cs
+++ b/src/OnePeek.Api/OnePeekApi.cs
@@ -11,7 +11,7 @@ using System.Threading;
 
 namespace OnePeek.Api
 {
-  public class OnePeekApi : ApiBase
+  public class OnePeekApi : ApiBase, IOnePeekApi
   {
     /// <summary>
     /// Searches for apps based on a term (app name, keywords, ..)
@@ -238,6 +238,15 @@ namespace OnePeek.Api
 
 
 
+    /// <summary>
+    /// Gets metadata for an app for all available cultures
+    /// Warning: This method makes a request per culture (100+) which can take a while.
+    /// </summary>
+    /// <param name="appId">The ID of the app. Can be found in the dev portal or the store URI.</param>
+    /// <param name="store">The store where the app is published.</param>
+    /// <param name="ct">The canellation token.</param>
+    /// <param name="progress">The progress event gets triggered as soon as new data arrives.</param>
+    /// <returns></returns>
     public async Task<IEnumerable<AppMetadata>> GetMetadataForAllCultures(string appId, StoreType store, CancellationToken ct, IProgress<DownloadProgressChangedEventArgs> progress)
     {
       IEnumerable<StoreCultureType> cultures = Enum.GetValues(typeof(StoreCultureType))
@@ -253,6 +262,16 @@ namespace OnePeek.Api
     }
 
 
+
+    /// <summary>
+    /// Gets ratings for an app for all available cultures
+    /// Warning: This method makes a request per culture (100+) which can take a while.
+    /// </summary>
+    /// <param name="appId">The ID of the app. Can be found in the dev portal or the store URI.</param>
+    /// <param name="store">The store where the app is published.</param>
+    /// <param name="ct">The canellation token.</param>
+    /// <param name="progress">The progress event gets triggered as soon as new data arrives.</param>
+    /// <returns></returns>
     public async Task<IEnumerable<AppRating>> GetRatingsForAllCultures(string appId, StoreType store, CancellationToken ct, IProgress<DownloadProgressChangedEventArgs> progress)
     {
       IEnumerable<StoreCultureType> cultures = Enum.GetValues(typeof(StoreCultureType))