diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/DefaultHttpRequestHandler.cs b/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/DefaultHttpRequestHandler.cs
index 4ef1d80c9cd..090f23a2c09 100644
--- a/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/DefaultHttpRequestHandler.cs
+++ b/dotnet/src/Microsoft.Agents.AI.Workflows.Declarative/DefaultHttpRequestHandler.cs
@@ -121,8 +121,7 @@ public async Task<HttpRequestResult> SendAsync(HttpRequestInfo request, Cancella
             throw new ArgumentException("Request method must be provided.", nameof(request));
         }
 
-        HttpRequestInfo currentRequest = request;
-        Uri currentUri = CreateAbsoluteUri(ResolveRequestUri(request));
+        HttpRequestInfo currentRequest = CreateCanonicalRequestInfo(request, out Uri currentUri);
 
         using CancellationTokenSource? timeoutCts = request.Timeout is { } timeout && timeout > TimeSpan.Zero
             ? CancellationTokenSource.CreateLinkedTokenSource(cancellationToken)
@@ -306,6 +305,21 @@ private static Uri CreateAbsoluteUri(string requestUri)
         return uri;
     }
 
+    private static HttpRequestInfo CreateCanonicalRequestInfo(HttpRequestInfo request, out Uri uri)
+    {
+        uri = CreateAbsoluteUri(ResolveRequestUri(request));
+        return new HttpRequestInfo
+        {
+            Method = request.Method,
+            Url = uri.ToString(),
+            Headers = request.Headers,
+            BodyContentType = request.BodyContentType,
+            Body = request.Body,
+            Timeout = request.Timeout,
+            ConnectionName = request.ConnectionName,
+        };
+    }
+
     private static bool TryCreateRedirectRequest(
         HttpResponseMessage response,
         HttpRequestInfo currentRequest,
diff --git a/dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.UnitTests/DefaultHttpRequestHandlerTests.cs b/dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.UnitTests/DefaultHttpRequestHandlerTests.cs
index d4669923a84..2d0cfbc8c1c 100644
--- a/dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.UnitTests/DefaultHttpRequestHandlerTests.cs
+++ b/dotnet/tests/Microsoft.Agents.AI.Workflows.Declarative.UnitTests/DefaultHttpRequestHandlerTests.cs
@@ -895,6 +895,49 @@ public async Task SendAsyncProviderClientAllowsScopedDefaultHeadersOnInitialRequ
         Assert.Equal(1, providerCallCount);
     }
 
+    [Fact]
+    public async Task SendAsyncInvokesProviderWithCanonicalRequestUriAsync()
+    {
+        // Arrange
+        CancellationToken cancellationToken = TestContext.Current.CancellationToken;
+        List<string> providerUrls = [];
+        List<string> requestUrls = [];
+        using HttpResponseMessage okResponse = new(HttpStatusCode.OK)
+        {
+            Content = new StringContent("ok", Encoding.UTF8, "text/plain"),
+        };
+#pragma warning disable CA2025
+        TestHttpMessageHandler messageHandler = new((req, _) =>
+        {
+            requestUrls.Add(req.RequestUri!.ToString());
+            return Task.FromResult(okResponse);
+        });
+#pragma warning restore CA2025
+        using HttpClient providerClient = new(messageHandler);
+#pragma warning disable CA2025
+        await using DefaultHttpRequestHandler handler = new((info, _) =>
+        {
+            providerUrls.Add(info.Url);
+            return Task.FromResult<HttpClient?>(providerClient);
+        });
+#pragma warning restore CA2025
+
+        HttpRequestInfo request = new()
+        {
+            Method = "GET",
+            Url = "https://api.example.test/public/../admin/private",
+        };
+
+        // Act
+        HttpRequestResult result = await handler.SendAsync(request, cancellationToken);
+
+        // Assert - the provider must authorize the same canonical URI that reaches
+        // HttpClient, not the raw dot-segment URL from the workflow definition.
+        Assert.Equal("ok", result.Body);
+        Assert.Equal(["https://api.example.test/admin/private"], requestUrls);
+        Assert.Equal(requestUrls, providerUrls);
+    }
+
     [Fact]
     public async Task SendAsyncSuppliedClientReturnsRedirectResponseAsync()
     {