Add User-Agent header support to Weaviate client and tests

src/Weaviate.Client.Tests/Unit/TestRestClient.cs

@@ -375,25 +375,42 @@ await client.Collections.Create(
         Assert.All(handler.Requests, req => req.ShouldHaveMethod(HttpMethod.Post));
     }
 
-    // Helper class for typed data test
     /// <summary>
-    /// The product data class
+    /// Tests that the X-Weaviate-Client header is set with the correct UserAgent value
     /// </summary>
-    private class ProductData
+    [Fact]
+    public async Task Client_SetsUserAgentHeader()
     {
-        /// <summary>
-        /// Gets or sets the value of the name
-        /// </summary>
-        public string Name { get; set; } = string.Empty;
-
-        /// <summary>
-        /// Gets or sets the value of the price
-        /// </summary>
-        public double Price { get; set; }
-
-        /// <summary>
-        /// Gets or sets the value of the in stock
-        /// </summary>
-        public bool InStock { get; set; }
+        // Arrange
+        var (client, handler) = MockWeaviateClient.CreateWithMockHandler();
+
+        // Mock a simple response
+        var mockResponse = new Dto.Class { Class1 = "TestCollection", Vectorizer = "none" };
+
+        handler.AddJsonResponse(mockResponse);
+
+        var config = new CollectionCreateParams { Name = "TestCollection" };
+
+        // Act
+        await client.Collections.Create(config, TestContext.Current.CancellationToken);
+
+        // Assert
+        Assert.NotNull(handler.LastRequest);
+
+        // Verify the X-Weaviate-Client header is present
+        Assert.True(
+            handler.LastRequest!.Headers.Contains("X-Weaviate-Client"),
+            "X-Weaviate-Client header should be present"
+        );
+
+        // Verify the header value matches the UserAgent
+        var headerValues = handler.LastRequest.Headers.GetValues("X-Weaviate-Client");
+        var actualUserAgent = headerValues.FirstOrDefault();
+
+        Assert.NotNull(actualUserAgent);
+        Assert.Equal(WeaviateDefaults.UserAgent, actualUserAgent);
+
+        // Verify the format includes version
+        Assert.Matches(@"^weaviate-client-csharp/\d+\.\d+\.\d+", actualUserAgent);
     }
 }

src/Weaviate.Client/Weaviate.Client.csproj

@@ -54,6 +54,7 @@
     <AdditionalFiles Include="PublicAPI.Unshipped.txt" />
   </ItemGroup>
   <PropertyGroup>
+    <MinVerDefaultPreReleaseIdentifiers>pre</MinVerDefaultPreReleaseIdentifiers>
     <MinVerSkip Condition="'$(Configuration)' == 'Debug'">true</MinVerSkip>
   </PropertyGroup>
 </Project>

src/Weaviate.Client/WeaviateClient.cs

@@ -477,6 +477,8 @@ ILogger<WeaviateClient> logger
             );
         }
 
+        httpClient.DefaultRequestHeaders.Add("X-Weaviate-Client", WeaviateDefaults.UserAgent);
+
         if (config.Headers != null)
         {
             foreach (var header in config.Headers)

src/Weaviate.Client/WeaviateDefaults.cs

@@ -33,4 +33,11 @@ public static class WeaviateDefaults
     /// Default retry policy applied when a client does not specify one explicitly.
     /// </summary>
     public static RetryPolicy DefaultRetryPolicy { get; set; } = RetryPolicy.Default;
+
+    /// <summary>
+    /// Gets or sets the default User-Agent headers sent by the client.
+    /// This can be used to identify the client or provide additional metadata in requests.
+    /// </summary>
+    public static string UserAgent =>
+        $"weaviate-client-csharp/{typeof(WeaviateClient).Assembly.GetName().Version}";
 }

src/Weaviate.Client/gRPC/Client.cs

@@ -77,6 +77,8 @@ internal WeaviateGrpcClient(
                 _defaultHeaders = new Metadata();
             }
 
+            _defaultHeaders.Add("X-Weaviate-Client", WeaviateDefaults.UserAgent);
+
             foreach (var header in headers)
             {
                 _defaultHeaders.Add(header.Key, header.Value);