diff --git a/sdk/src/main/java/io/dapr/client/DaprBodyPublishers.java b/sdk/src/main/java/io/dapr/client/DaprBodyPublishers.java
index 37651e30b..4c48bef91 100644
--- a/sdk/src/main/java/io/dapr/client/DaprBodyPublishers.java
+++ b/sdk/src/main/java/io/dapr/client/DaprBodyPublishers.java
@@ -59,6 +59,18 @@ private DaprBodyPublishers() {
    * <p>Callers are still responsible for setting an appropriate
    * {@code Content-Type} header (typically {@code application/json}).
    *
+   * <p>This helper is a convenience for the default-serializer case. It does
+   * <em>not</em> honor a custom {@link io.dapr.serializer.DaprObjectSerializer}
+   * configured on the {@link DaprClientBuilder}. Callers with a custom serializer
+   * should serialize the value themselves and wrap the resulting bytes:
+   * <pre>{@code
+   * byte[] bytes = mySerializer.serialize(value);
+   * BodyPublisher body = HttpRequest.BodyPublishers.ofByteArray(bytes);
+   * }</pre>
+   * The only behavior this helper adds over a direct {@code ofByteArray} call is
+   * choosing a length-known {@link BodyPublisher} so the JDK emits
+   * {@code Content-Length} rather than {@code Transfer-Encoding: chunked}.
+   *
    * @param value object to serialize; {@code null} yields an empty body.
    * @return a body publisher carrying the JSON-encoded bytes.
    * @throws UncheckedIOException if serialization fails.
diff --git a/sdk/src/main/java/io/dapr/client/DaprInvokeHttpClient.java b/sdk/src/main/java/io/dapr/client/DaprInvokeHttpClient.java
index 34564dcbb..f13edb6cf 100644
--- a/sdk/src/main/java/io/dapr/client/DaprInvokeHttpClient.java
+++ b/sdk/src/main/java/io/dapr/client/DaprInvokeHttpClient.java
@@ -13,6 +13,8 @@
 
 package io.dapr.client;
 
+import io.dapr.utils.Version;
+
 import java.io.IOException;
 import java.net.URI;
 import java.net.http.HttpClient;
@@ -100,8 +102,9 @@ public URI baseUri() {
 
   /**
    * Creates an {@link HttpRequest.Builder} pre-bound to the Dapr invoke URL for the
-   * configured app id, with the {@code dapr-api-token} header attached (when one is
-   * configured) and the SDK's HTTP read timeout applied.
+   * configured app id, with the SDK {@code User-Agent} header attached, the
+   * {@code dapr-api-token} header attached (when one is configured) and the SDK's
+   * HTTP read timeout applied.
    *
    * <p>The {@code relativePath} is resolved against {@link #baseUri()} via
    * {@link URI#resolve(String)}. Per {@link URI#resolve(String)} semantics, a leading
@@ -113,7 +116,9 @@ public URI baseUri() {
    */
   public HttpRequest.Builder newRequestBuilder(String relativePath) {
     Objects.requireNonNull(relativePath, "relativePath");
-    HttpRequest.Builder builder = HttpRequest.newBuilder().uri(baseUri.resolve(relativePath));
+    HttpRequest.Builder builder = HttpRequest.newBuilder()
+        .uri(baseUri.resolve(relativePath))
+        .header(Headers.DAPR_USER_AGENT, Version.getSdkVersion());
     if (daprApiToken != null && !daprApiToken.isEmpty()) {
       builder.header(Headers.DAPR_API_TOKEN, daprApiToken);
     }
diff --git a/sdk/src/test/java/io/dapr/client/DaprInvokeHttpClientTest.java b/sdk/src/test/java/io/dapr/client/DaprInvokeHttpClientTest.java
index 826f9583f..c3c0514a0 100644
--- a/sdk/src/test/java/io/dapr/client/DaprInvokeHttpClientTest.java
+++ b/sdk/src/test/java/io/dapr/client/DaprInvokeHttpClientTest.java
@@ -13,6 +13,7 @@
 
 package io.dapr.client;
 
+import io.dapr.utils.Version;
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
 
@@ -80,6 +81,16 @@ public void newRequestBuilder_resolvesRelativePathAgainstBaseUri() {
         request.uri().toString());
   }
 
+  @Test
+  public void newRequestBuilder_attachesSdkUserAgentHeader() {
+    DaprInvokeHttpClient invoker = new DaprInvokeHttpClient(httpClient, BASE_URI, null, null);
+
+    HttpRequest request = invoker.newRequestBuilder("orders").GET().build();
+
+    assertEquals(Version.getSdkVersion(),
+        request.headers().firstValue(Headers.DAPR_USER_AGENT).orElse(null));
+  }
+
   @Test
   public void newRequestBuilder_attachesApiTokenHeaderWhenConfigured() {
     DaprInvokeHttpClient invoker = new DaprInvokeHttpClient(httpClient, BASE_URI, "xyz", null);