diff --git a/communication/src/main/java/datadog/communication/serialization/custom/aiguard/MessageWriter.java b/communication/src/main/java/datadog/communication/serialization/custom/aiguard/MessageWriter.java
index a1b089fbb1c..b057409e726 100644
--- a/communication/src/main/java/datadog/communication/serialization/custom/aiguard/MessageWriter.java
+++ b/communication/src/main/java/datadog/communication/serialization/custom/aiguard/MessageWriter.java
@@ -14,16 +14,51 @@ public void write(
       final AIGuard.Message value, final Writable writable, final EncodingCache encodingCache) {
     final int[] size = {0};
     final boolean hasRole = isNotBlank(value.getRole(), size);
-    final boolean hasContent = isNotBlank(value.getContent(), size);
     final boolean hasToolCallId = isNotBlank(value.getToolCallId(), size);
     final boolean hasToolCalls = isNotEmpty(value.getToolCalls(), size);
+
+    final boolean hasContentParts = isNotEmpty(value.getContentParts(), size);
+    final boolean hasContent = !hasContentParts && isNotBlank(value.getContent(), size);
+
     writable.startMap(size[0]);
     writeString(hasRole, "role", value.getRole(), writable, encodingCache);
-    writeString(hasContent, "content", value.getContent(), writable, encodingCache);
+
+    if (hasContentParts) {
+      writeContentParts("content", value.getContentParts(), writable, encodingCache);
+    } else {
+      writeString(hasContent, "content", value.getContent(), writable, encodingCache);
+    }
+
     writeString(hasToolCallId, "tool_call_id", value.getToolCallId(), writable, encodingCache);
     writeToolCallArray(hasToolCalls, "tool_calls", value.getToolCalls(), writable, encodingCache);
   }
 
+  private static void writeContentParts(
+      final String key,
+      final List<AIGuard.ContentPart> contentParts,
+      final Writable writable,
+      final EncodingCache encodingCache) {
+    writable.writeString(key, encodingCache);
+    writable.startArray(contentParts.size());
+
+    for (final AIGuard.ContentPart part : contentParts) {
+      writable.startMap(2);
+
+      writable.writeString("type", encodingCache);
+      writable.writeString(part.getType().toString(), encodingCache);
+
+      if (part.getType() == AIGuard.ContentPart.Type.TEXT) {
+        writable.writeString("text", encodingCache);
+        writable.writeString(part.getText(), encodingCache);
+      } else if (part.getType() == AIGuard.ContentPart.Type.IMAGE_URL) {
+        writable.writeString("image_url", encodingCache);
+        writable.startMap(1);
+        writable.writeString("url", encodingCache);
+        writable.writeString(part.getImageUrl().getUrl(), encodingCache);
+      }
+    }
+  }
+
   private static void writeString(
       final boolean present,
       final String key,
diff --git a/communication/src/test/groovy/datadog/communication/serialization/aiguard/MessageWriterTest.groovy b/communication/src/test/groovy/datadog/communication/serialization/aiguard/MessageWriterTest.groovy
index 3328a2330ad..45191a2fc8f 100644
--- a/communication/src/test/groovy/datadog/communication/serialization/aiguard/MessageWriterTest.groovy
+++ b/communication/src/test/groovy/datadog/communication/serialization/aiguard/MessageWriterTest.groovy
@@ -116,4 +116,127 @@ class MessageWriterTest extends DDSpecification {
   private static String asString(final Value value) {
     return value.asStringValue().asString()
   }
+
+  void 'test write message with text content parts'() {
+    given:
+    final message = AIGuard.Message.message('user', [
+      AIGuard.ContentPart.text('Hello world')
+    ])
+
+    when:
+    writer.writeObject(message, encodingCache)
+
+    then:
+    try (final unpacker = MessagePack.newDefaultUnpacker(buffer.slice())) {
+      final value = asStringKeyMap(unpacker.unpackValue())
+      value.size() == 2
+      asString(value.role) == 'user'
+
+      final contentParts = value.content.asArrayValue().list()
+      contentParts.size() == 1
+
+      final part = asStringKeyMap(contentParts[0])
+      asString(part.type) == 'text'
+      asString(part.text) == 'Hello world'
+    }
+  }
+
+  void 'test write message with image_url content parts'() {
+    given:
+    final message = AIGuard.Message.message('user', [
+      AIGuard.ContentPart.imageUrl('https://example.com/image.jpg')
+    ])
+
+    when:
+    writer.writeObject(message, encodingCache)
+
+    then:
+    try (final unpacker = MessagePack.newDefaultUnpacker(buffer.slice())) {
+      final value = asStringKeyMap(unpacker.unpackValue())
+      value.size() == 2
+      asString(value.role) == 'user'
+
+      final contentParts = value.content.asArrayValue().list()
+      contentParts.size() == 1
+
+      final part = asStringKeyMap(contentParts[0])
+      asString(part.type) == 'image_url'
+
+      final imageUrl = asStringKeyMap(part.image_url)
+      asString(imageUrl.url) == 'https://example.com/image.jpg'
+    }
+  }
+
+  void 'test write message with mixed content parts'() {
+    given:
+    final message = AIGuard.Message.message('user', [
+      AIGuard.ContentPart.text('Describe this:'),
+      AIGuard.ContentPart.imageUrl('https://example.com/image.jpg'),
+      AIGuard.ContentPart.text('What is it?')
+    ])
+
+    when:
+    writer.writeObject(message, encodingCache)
+
+    then:
+    try (final unpacker = MessagePack.newDefaultUnpacker(buffer.slice())) {
+      final value = asStringKeyMap(unpacker.unpackValue())
+      value.size() == 2
+      asString(value.role) == 'user'
+
+      final contentParts = value.content.asArrayValue().list()
+      contentParts.size() == 3
+
+      final part1 = asStringKeyMap(contentParts[0])
+      asString(part1.type) == 'text'
+      asString(part1.text) == 'Describe this:'
+
+      final part2 = asStringKeyMap(contentParts[1])
+      asString(part2.type) == 'image_url'
+      final imageUrl = asStringKeyMap(part2.image_url)
+      asString(imageUrl.url) == 'https://example.com/image.jpg'
+
+      final part3 = asStringKeyMap(contentParts[2])
+      asString(part3.type) == 'text'
+      asString(part3.text) == 'What is it?'
+    }
+  }
+
+  void 'test content parts type serializes as string not integer'() {
+    given:
+    final message = AIGuard.Message.message('user', [
+      AIGuard.ContentPart.text('Test')
+    ])
+
+    when:
+    writer.writeObject(message, encodingCache)
+
+    then:
+    try (final unpacker = MessagePack.newDefaultUnpacker(buffer.slice())) {
+      final value = asStringKeyMap(unpacker.unpackValue())
+      final contentParts = value.content.asArrayValue().list()
+      final part = asStringKeyMap(contentParts[0])
+
+      // Verify type is a string value, not an integer
+      part.type.isStringValue()
+      !part.type.isIntegerValue()
+      asString(part.type) == 'text'
+    }
+  }
+
+  void 'test backward compatibility with string content'() {
+    given:
+    final message = AIGuard.Message.message('user', 'Plain text message')
+
+    when:
+    writer.writeObject(message, encodingCache)
+
+    then:
+    try (final unpacker = MessagePack.newDefaultUnpacker(buffer.slice())) {
+      final value = asStringValueMap(unpacker.unpackValue())
+      value.size() == 2
+      value.role == 'user'
+      value.content == 'Plain text message'
+    }
+  }
 }
diff --git a/dd-java-agent/agent-aiguard/src/main/java/com/datadog/aiguard/AIGuardInternal.java b/dd-java-agent/agent-aiguard/src/main/java/com/datadog/aiguard/AIGuardInternal.java
index cae66ce7e10..2ee18ba2b8a 100644
--- a/dd-java-agent/agent-aiguard/src/main/java/com/datadog/aiguard/AIGuardInternal.java
+++ b/dd-java-agent/agent-aiguard/src/main/java/com/datadog/aiguard/AIGuardInternal.java
@@ -16,6 +16,7 @@
 import datadog.trace.api.aiguard.AIGuard.AIGuardAbortError;
 import datadog.trace.api.aiguard.AIGuard.AIGuardClientError;
 import datadog.trace.api.aiguard.AIGuard.Action;
+import datadog.trace.api.aiguard.AIGuard.ContentPart;
 import datadog.trace.api.aiguard.AIGuard.Evaluation;
 import datadog.trace.api.aiguard.AIGuard.Message;
 import datadog.trace.api.aiguard.AIGuard.Options;
@@ -136,16 +137,44 @@ private static List<Message> messagesForMetaStruct(List<Message> messages) {
     boolean contentTruncated = false;
     for (int i = messages.size() - size; i < messages.size(); i++) {
       final Message source = messages.get(i);
-      String content = source.getContent();
-      if (content != null && content.length() > maxContent) {
-        contentTruncated = true;
-        content = content.substring(0, maxContent);
-      }
-      List<ToolCall> toolCalls = source.getToolCalls();
-      if (toolCalls != null) {
-        toolCalls = new ArrayList<>(toolCalls);
+
+      List<ContentPart> contentParts = source.getContentParts();
+      if (contentParts != null) {
+        final List<ContentPart> truncatedParts = new ArrayList<>(contentParts.size());
+        for (final ContentPart part : contentParts) {
+          if (part.getType() == ContentPart.Type.TEXT) {
+            String text = part.getText();
+            if (text != null && text.length() > maxContent) {
+              contentTruncated = true;
+              text = text.substring(0, maxContent);
+              truncatedParts.add(ContentPart.text(text));
+            } else {
+              truncatedParts.add(part);
+            }
+          } else {
+            truncatedParts.add(part);
+          }
+        }
+
+        List<ToolCall> toolCalls = source.getToolCalls();
+        if (toolCalls != null) {
+          toolCalls = new ArrayList<>(toolCalls);
+        }
+        result.add(
+            new Message(source.getRole(), truncatedParts, toolCalls, source.getToolCallId()));
+      } else {
+        // Handle plain text content (backward compatibility)
+        String content = source.getContent();
+        if (content != null && content.length() > maxContent) {
+          contentTruncated = true;
+          content = content.substring(0, maxContent);
+        }
+        List<ToolCall> toolCalls = source.getToolCalls();
+        if (toolCalls != null) {
+          toolCalls = new ArrayList<>(toolCalls);
+        }
+        result.add(new Message(source.getRole(), content, toolCalls, source.getToolCallId()));
       }
-      result.add(new Message(source.getRole(), content, toolCalls, source.getToolCallId()));
     }
     if (contentTruncated) {
       WafMetricCollector.get().aiGuardTruncated(CONTENT);
@@ -333,12 +362,45 @@ public Message fromJson(JsonReader reader) throws IOException {
     public void toJson(final JsonWriter writer, final Message value) throws IOException {
       writer.beginObject();
       writeValue(writer, "role", value.getRole());
-      writeValue(writer, "content", value.getContent());
+
+      if (value.getContentParts() != null) {
+        writeContentParts(writer, "content", value.getContentParts());
+      } else {
+        writeValue(writer, "content", value.getContent());
+      }
+
       writeArray(writer, "tool_calls", value.getToolCalls());
       writeValue(writer, "tool_call_id", value.getToolCallId());
       writer.endObject();
     }
 
+    private void writeContentParts(
+        final JsonWriter writer, final String name, final List<ContentPart> contentParts)
+        throws IOException {
+      writer.name(name);
+      writer.beginArray();
+      for (final ContentPart part : contentParts) {
+        writer.beginObject();
+
+        writer.name("type");
+        writer.value(part.getType().toString());
+
+        if (part.getType() == ContentPart.Type.TEXT) {
+          writer.name("text");
+          writer.value(part.getText());
+        } else if (part.getType() == ContentPart.Type.IMAGE_URL) {
+          writer.name("image_url");
+          writer.beginObject();
+          writer.name("url");
+          writer.value(part.getImageUrl().getUrl());
+          writer.endObject();
+        }
+
+        writer.endObject();
+      }
+      writer.endArray();
+    }
+
     private void writeValue(final JsonWriter writer, final String name, final Object value)
         throws IOException {
       if (value != null) {
diff --git a/dd-java-agent/agent-aiguard/src/test/groovy/com/datadog/aiguard/AIGuardInternalTests.groovy b/dd-java-agent/agent-aiguard/src/test/groovy/com/datadog/aiguard/AIGuardInternalTests.groovy
index f7c9de745ca..e3a5ffd6671 100644
--- a/dd-java-agent/agent-aiguard/src/test/groovy/com/datadog/aiguard/AIGuardInternalTests.groovy
+++ b/dd-java-agent/agent-aiguard/src/test/groovy/com/datadog/aiguard/AIGuardInternalTests.groovy
@@ -365,7 +365,7 @@ class AIGuardInternalTests extends DDSpecification {
     final messages = [
       new AIGuard.Message(
       "assistant",
-      null,
+      (String) null,
       [AIGuard.ToolCall.toolCall('call_1', 'execute_shell', '{"cmd": "ls -lah"}')],
       null
       )
@@ -470,6 +470,180 @@ class AIGuardInternalTests extends DDSpecification {
     .build()
   }
 
+  void 'test JSON serialization with text content parts'() {
+    given:
+    final aiguard = mockClient(200, [data: [attributes: [action: 'ALLOW', reason: 'Good']]])
+    final messages = [AIGuard.Message.message('user', [AIGuard.ContentPart.text('Hello world')])]
+
+    when:
+    aiguard.evaluate(messages, AIGuard.Options.DEFAULT)
+
+    then:
+    1 * span.setMetaStruct(AIGuardInternal.META_STRUCT_TAG, _) >> {
+      final meta = it[1] as Map<String, Object>
+      final receivedMessages = meta.messages as List<AIGuard.Message>
+      assert receivedMessages.size() == 1
+      assert receivedMessages[0].contentParts.size() == 1
+      assert receivedMessages[0].contentParts[0].type == AIGuard.ContentPart.Type.TEXT
+      assert receivedMessages[0].contentParts[0].text == 'Hello world'
+      return span
+    }
+  }
+
+  void 'test JSON serialization with image_url content parts'() {
+    given:
+    final aiguard = mockClient(200, [data: [attributes: [action: 'ALLOW', reason: 'Good']]])
+    final messages = [
+      AIGuard.Message.message('user', [AIGuard.ContentPart.imageUrl('https://example.com/image.jpg')])
+    ]
+
+    when:
+    aiguard.evaluate(messages, AIGuard.Options.DEFAULT)
+
+    then:
+    1 * span.setMetaStruct(AIGuardInternal.META_STRUCT_TAG, _) >> {
+      final meta = it[1] as Map<String, Object>
+      final receivedMessages = meta.messages as List<AIGuard.Message>
+      assert receivedMessages.size() == 1
+      assert receivedMessages[0].contentParts.size() == 1
+      assert receivedMessages[0].contentParts[0].type == AIGuard.ContentPart.Type.IMAGE_URL
+      assert receivedMessages[0].contentParts[0].imageUrl.url == 'https://example.com/image.jpg'
+      return span
+    }
+  }
+
+  void 'test JSON serialization with mixed content parts'() {
+    given:
+    final aiguard = mockClient(200, [data: [attributes: [action: 'ALLOW', reason: 'Good']]])
+    final messages = [
+      AIGuard.Message.message('user', [
+        AIGuard.ContentPart.text('Describe this image:'),
+        AIGuard.ContentPart.imageUrl('https://example.com/image.jpg'),
+        AIGuard.ContentPart.text('What do you see?')
+      ])
+    ]
+
+    when:
+    aiguard.evaluate(messages, AIGuard.Options.DEFAULT)
+
+    then:
+    1 * span.setMetaStruct(AIGuardInternal.META_STRUCT_TAG, _) >> {
+      final meta = it[1] as Map<String, Object>
+      final receivedMessages = meta.messages as List<AIGuard.Message>
+      assert receivedMessages.size() == 1
+      assert receivedMessages[0].contentParts.size() == 3
+      assert receivedMessages[0].contentParts[0].type == AIGuard.ContentPart.Type.TEXT
+      assert receivedMessages[0].contentParts[0].text == 'Describe this image:'
+      assert receivedMessages[0].contentParts[1].type == AIGuard.ContentPart.Type.IMAGE_URL
+      assert receivedMessages[0].contentParts[1].imageUrl.url == 'https://example.com/image.jpg'
+      assert receivedMessages[0].contentParts[2].type == AIGuard.ContentPart.Type.TEXT
+      assert receivedMessages[0].contentParts[2].text == 'What do you see?'
+      return span
+    }
+  }
+
+  void 'test content parts order is preserved'() {
+    given:
+    final aiguard = mockClient(200, [data: [attributes: [action: 'ALLOW', reason: 'Good']]])
+    final parts = (0..4).collect {
+      it % 2 == 0 ? AIGuard.ContentPart.text("Text $it") : AIGuard.ContentPart.imageUrl("https://example.com/image${it}.jpg")
+    }
+    final messages = [AIGuard.Message.message('user', parts)]
+
+    when:
+    aiguard.evaluate(messages, AIGuard.Options.DEFAULT)
+
+    then:
+    1 * span.setMetaStruct(AIGuardInternal.META_STRUCT_TAG, _) >> {
+      final meta = it[1] as Map<String, Object>
+      final receivedMessages = meta.messages as List<AIGuard.Message>
+      assert receivedMessages[0].contentParts.size() == 5
+      (0..4).each { i ->
+        if (i % 2 == 0) {
+          assert receivedMessages[0].contentParts[i].type == AIGuard.ContentPart.Type.TEXT
+          assert receivedMessages[0].contentParts[i].text == "Text $i"
+        } else {
+          assert receivedMessages[0].contentParts[i].type == AIGuard.ContentPart.Type.IMAGE_URL
+          assert receivedMessages[0].contentParts[i].imageUrl.url == "https://example.com/image${i}.jpg"
+        }
+      }
+      return span
+    }
+  }
+
+  void 'test content part text truncation'() {
+    given:
+    final maxContent = Config.get().getAiGuardMaxContentSize()
+    final aiguard = mockClient(200, [data: [attributes: [action: 'ALLOW', reason: 'Good']]])
+    final longText = (0..maxContent).collect { 'A' }.join()
+    final messages = [
+      AIGuard.Message.message('user', [AIGuard.ContentPart.text(longText), AIGuard.ContentPart.text('Short text')])
+    ]
+
+    when:
+    aiguard.evaluate(messages, AIGuard.Options.DEFAULT)
+
+    then:
+    1 * span.setMetaStruct(AIGuardInternal.META_STRUCT_TAG, _) >> {
+      final meta = it[1] as Map<String, Object>
+      final receivedMessages = meta.messages as List<AIGuard.Message>
+      assert receivedMessages[0].contentParts.size() == 2
+      assert receivedMessages[0].contentParts[0].text.length() == maxContent
+      assert receivedMessages[0].contentParts[0].text.length() < longText.length()
+      assert receivedMessages[0].contentParts[1].text == 'Short text'
+      return span
+    }
+    assertTelemetry('ai_guard.truncated', 'type:content')
+  }
+
+  void 'test content part image_url not truncated even with long data URI'() {
+    given:
+    final maxContent = Config.get().getAiGuardMaxContentSize()
+    final aiguard = mockClient(200, [data: [attributes: [action: 'ALLOW', reason: 'Good']]])
+    // Create a very long data URI (longer than max content size)
+    final longDataUri = 'data:image/png;base64,' + (0..(maxContent + 1000)).collect { 'A' }.join()
+    final messages = [
+      AIGuard.Message.message('user', [
+        AIGuard.ContentPart.text('Image:'),
+        AIGuard.ContentPart.imageUrl(longDataUri)
+      ])
+    ]
+
+    when:
+    aiguard.evaluate(messages, AIGuard.Options.DEFAULT)
+
+    then:
+    1 * span.setMetaStruct(AIGuardInternal.META_STRUCT_TAG, _) >> {
+      final meta = it[1] as Map<String, Object>
+      final receivedMessages = meta.messages as List<AIGuard.Message>
+      assert receivedMessages[0].contentParts.size() == 2
+      assert receivedMessages[0].contentParts[1].type == AIGuard.ContentPart.Type.IMAGE_URL
+      // Image URL should NOT be truncated
+      assert receivedMessages[0].contentParts[1].imageUrl.url == longDataUri
+      assert receivedMessages[0].contentParts[1].imageUrl.url.length() > maxContent
+      return span
+    }
+  }
+
+  void 'test backward compatibility with string content'() {
+    given:
+    final aiguard = mockClient(200, [data: [attributes: [action: 'ALLOW', reason: 'Good']]])
+    final messages = [AIGuard.Message.message('user', 'Hello world')]
+
+    when:
+    aiguard.evaluate(messages, AIGuard.Options.DEFAULT)
+
+    then:
+    1 * span.setMetaStruct(AIGuardInternal.META_STRUCT_TAG, _) >> {
+      final meta = it[1] as Map<String, Object>
+      final receivedMessages = meta.messages as List<AIGuard.Message>
+      assert receivedMessages.size() == 1
+      assert receivedMessages[0].content == 'Hello world'
+      assert receivedMessages[0].contentParts == null
+      return span
+    }
+  }
+
   private static class TestSuite {
     private final AIGuard.Action action
     private final String reason
diff --git a/dd-smoke-tests/appsec/springboot/src/main/java/datadog/smoketest/appsec/springboot/controller/AIGuardController.java b/dd-smoke-tests/appsec/springboot/src/main/java/datadog/smoketest/appsec/springboot/controller/AIGuardController.java
index fc3cb3942be..45048aba231 100644
--- a/dd-smoke-tests/appsec/springboot/src/main/java/datadog/smoketest/appsec/springboot/controller/AIGuardController.java
+++ b/dd-smoke-tests/appsec/springboot/src/main/java/datadog/smoketest/appsec/springboot/controller/AIGuardController.java
@@ -65,6 +65,21 @@ public ResponseEntity<?> abort(final @RequestHeader("X-Blocking-Enabled") boolea
     }
   }
 
+  @GetMapping(value = "/multimodal")
+  public ResponseEntity<?> multimodal() {
+    final Evaluation result =
+        AIGuard.evaluate(
+            asList(
+                Message.message("system", "You are a beautiful AI"),
+                Message.message(
+                    "user",
+                    asList(
+                        AIGuard.ContentPart.text("Describe this image:"),
+                        AIGuard.ContentPart.imageUrl("https://example.com/image.jpg"),
+                        AIGuard.ContentPart.text("What do you see?")))));
+    return ResponseEntity.ok(result);
+  }
+
   /** Mocking endpoint for the AI Guard REST API */
   @SuppressWarnings("unchecked")
   @PostMapping(
@@ -80,18 +95,40 @@ public ResponseEntity<Map<String, Object>> evaluate(
     final Map<String, Object> last = messages.get(messages.size() - 1);
     String action = "ALLOW";
     String reason = "The prompt looks harmless";
-    String content = (String) last.get("content");
-    if (content.startsWith("You should not trust me")) {
-      action = "DENY";
-      reason = "I am feeling suspicious today";
-    } else if (content.startsWith("Nuke yourself")) {
-      action = "ABORT";
-      reason = "The user is trying to destroy me";
+
+    // Handle both string content and content parts
+    Object contentObj = last.get("content");
+    String content = null;
+    boolean hasContentParts = false;
+
+    if (contentObj instanceof String) {
+      content = (String) contentObj;
+    } else if (contentObj instanceof List) {
+      // Content parts - check if it contains an image
+      List<Map<String, Object>> contentParts = (List<Map<String, Object>>) contentObj;
+      hasContentParts = true;
+      for (Map<String, Object> part : contentParts) {
+        if ("image_url".equals(part.get("type"))) {
+          reason = "Multimodal prompt detected";
+          break;
+        }
+      }
     }
+
+    if (content != null) {
+      if (content.startsWith("You should not trust me")) {
+        action = "DENY";
+        reason = "I am feeling suspicious today";
+      } else if (content.startsWith("Nuke yourself")) {
+        action = "ABORT";
+        reason = "The user is trying to destroy me";
+      }
+    }
+
     final Map<String, Object> evaluation = new HashMap<>(3);
     evaluation.put("action", action);
     evaluation.put("reason", reason);
-    evaluation.put("is_blocking_enabled", content.endsWith("[block]"));
+    evaluation.put("is_blocking_enabled", content != null && content.endsWith("[block]"));
     return ResponseEntity.ok()
         .body(Collections.singletonMap("data", Collections.singletonMap("attributes", evaluation)));
   }
diff --git a/dd-smoke-tests/appsec/springboot/src/test/groovy/datadog/smoketest/appsec/AIGuardSmokeTest.groovy b/dd-smoke-tests/appsec/springboot/src/test/groovy/datadog/smoketest/appsec/AIGuardSmokeTest.groovy
index 5c83d554269..973c96324ec 100644
--- a/dd-smoke-tests/appsec/springboot/src/test/groovy/datadog/smoketest/appsec/AIGuardSmokeTest.groovy
+++ b/dd-smoke-tests/appsec/springboot/src/test/groovy/datadog/smoketest/appsec/AIGuardSmokeTest.groovy
@@ -102,4 +102,62 @@ class AIGuardSmokeTest extends AbstractAppSecServerSmokeTest {
       }
     }
   }
+
+  void 'test multimodal content parts evaluation'() {
+    given:
+    def request = new Request.Builder()
+    .url("http://localhost:${httpPort}/aiguard/multimodal")
+    .get()
+    .build()
+
+    when:
+    final response = client.newCall(request).execute()
+
+    then:
+    assert response.code() == 200
+    final body = new JsonSlurper().parse(response.body().bytes())
+    assert body.reason == 'Multimodal prompt detected'
+    assert body.action == 'ALLOW'
+
+    and:
+    waitForTraceCount(2) // default call + internal API mock
+    final span = traces*.spans
+    ?.flatten()
+    ?.find {
+      it.resource == 'ai_guard'
+    } as DecodedSpan
+    assert span.meta.get('ai_guard.action') == 'ALLOW'
+    assert span.meta.get('ai_guard.reason') == 'Multimodal prompt detected'
+    assert span.meta.get('ai_guard.target') == 'prompt'
+
+    // Verify content parts in metaStruct
+    final messages = span.metaStruct.get('ai_guard').messages as List<Map<String, Object>>
+    assert messages.size() == 2
+    with(messages[0]) {
+      role == 'system'
+      content == 'You are a beautiful AI'
+    }
+    with(messages[1]) {
+      role == 'user'
+      def contentParts = it.content as List<Map<String, Object>>
+      assert contentParts != null
+      assert contentParts.size() == 3
+
+      with(contentParts[0]) {
+        type == 'text'
+        text == 'Describe this image:'
+      }
+
+      with(contentParts[1]) {
+        type == 'image_url'
+        def imageUrl = it.image_url as Map<String, Object>
+        assert imageUrl.url == 'https://example.com/image.jpg'
+      }
+
+      with(contentParts[2]) {
+        type == 'text'
+        text == 'What do you see?'
+      }
+    }
+  }
 }
diff --git a/dd-trace-api/src/main/java/datadog/trace/api/aiguard/AIGuard.java b/dd-trace-api/src/main/java/datadog/trace/api/aiguard/AIGuard.java
index 1a8c0a89dd7..ac76d349213 100644
--- a/dd-trace-api/src/main/java/datadog/trace/api/aiguard/AIGuard.java
+++ b/dd-trace-api/src/main/java/datadog/trace/api/aiguard/AIGuard.java
@@ -2,7 +2,12 @@
 
 import datadog.trace.api.aiguard.noop.NoOpEvaluator;
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
+import java.util.Locale;
+import java.util.Objects;
+import javax.annotation.Nonnull;
+import javax.annotation.Nullable;
 
 /**
  * SDK for calling the AIGuard REST API to evaluate AI prompts and tool calls for security threats.
@@ -186,16 +191,176 @@ public List<String> getTags() {
     }
   }
 
+  /**
+   * Represents an image URL in a content part. Images can be provided as URLs or data URIs.
+   *
+   * <p>Example usage:
+   *
+   * <pre>{@code
+   * // Image from URL
+   * var imageUrl = new AIGuard.ImageURL("https://example.com/image.jpg");
+   *
+   * // Image from data URI
+   * var dataUri = new AIGuard.ImageURL("data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAUA...");
+   * }</pre>
+   */
+  public static class ImageURL {
+
+    private final String url;
+
+    /**
+     * Creates a new ImageURL with the specified URL.
+     *
+     * @param url the image URL or data URI
+     * @throws NullPointerException if url is null
+     */
+    public ImageURL(@Nonnull final String url) {
+      this.url = Objects.requireNonNull(url, "url cannot be null");
+    }
+
+    /**
+     * Returns the image URL.
+     *
+     * @return the image URL or data URI
+     */
+    @Nonnull
+    public String getUrl() {
+      return url;
+    }
+  }
+
+  /**
+   * Represents a content part within a message. Content parts can be text or images, enabling
+   * multimodal AI prompts.
+   *
+   * <p>Example usage:
+   *
+   * <pre>{@code
+   * // Text content
+   * var textPart = AIGuard.ContentPart.text("Describe this image:");
+   *
+   * // Image content from URL
+   * var imagePart = AIGuard.ContentPart.imageUrl("https://example.com/image.jpg");
+   *
+   * // Multimodal message with text and image
+   * var message = AIGuard.Message.message("user", List.of(textPart, imagePart));
+   * }</pre>
+   */
+  public static class ContentPart {
+
+    /** Type of content part. */
+    public enum Type {
+      /** Text content */
+      TEXT,
+      /** Image URL content */
+      IMAGE_URL;
+
+      @Override
+      public String toString() {
+        return name().toLowerCase(Locale.ROOT);
+      }
+    }
+
+    private final Type type;
+    @Nullable private final String text;
+    @Nullable private final ImageURL imageUrl;
+
+    /**
+     * Package-private constructor to enforce use of factory methods.
+     *
+     * @param type the content part type
+     * @param text the text content (required for TEXT type)
+     * @param imageUrl the image URL (required for IMAGE_URL type)
+     */
+    ContentPart(
+        @Nonnull final Type type, @Nullable final String text, @Nullable final ImageURL imageUrl) {
+      this.type = type;
+      this.text = text;
+      this.imageUrl = imageUrl;
+
+      if (type == Type.TEXT && text == null) {
+        throw new IllegalArgumentException("text content part requires text field");
+      }
+      if (type == Type.IMAGE_URL && imageUrl == null) {
+        throw new IllegalArgumentException("image_url content part requires imageUrl field");
+      }
+    }
+
+    /**
+     * Returns the type of this content part.
+     *
+     * @return the content part type (TEXT or IMAGE_URL)
+     */
+    @Nonnull
+    public Type getType() {
+      return type;
+    }
+
+    /**
+     * Returns the text content of this part.
+     *
+     * @return the text content, or null if this is an IMAGE_URL part
+     */
+    @Nullable
+    public String getText() {
+      return text;
+    }
+
+    /**
+     * Returns the image URL of this part.
+     *
+     * @return the image URL, or null if this is a TEXT part
+     */
+    @Nullable
+    public ImageURL getImageUrl() {
+      return imageUrl;
+    }
+
+    /**
+     * Creates a text content part.
+     *
+     * @param text the text content
+     * @return a new ContentPart with TEXT type
+     * @throws NullPointerException if text is null
+     */
+    @Nonnull
+    public static ContentPart text(@Nonnull final String text) {
+      Objects.requireNonNull(text, "text cannot be null");
+      return new ContentPart(Type.TEXT, text, null);
+    }
+
+    /**
+     * Creates an image content part from a URL string.
+     *
+     * @param url the image URL or data URI
+     * @return a new ContentPart with IMAGE_URL type
+     * @throws NullPointerException if url is null
+     */
+    @Nonnull
+    public static ContentPart imageUrl(@Nonnull final String url) {
+      return new ContentPart(Type.IMAGE_URL, null, new ImageURL(url));
+    }
+  }
+
   /**
    * Represents a message in an AI conversation. Messages can represent user prompts, assistant
    * responses, system messages, or tool outputs.
    *
+   * <p>Messages can contain either plain text content or structured content parts (text and
+   * images):
+   *
    * <p>Example usage:
    *
    * <pre>{@code
-   * // User prompt
+   * // User prompt with text
    * var userPrompt = AIGuard.Message.message("user", "What's the weather like?");
    *
+   * // User prompt with text and image
+   * var multimodalPrompt = AIGuard.Message.message("user", List.of(
+   *     AIGuard.ContentPart.text("Describe this image:"),
+   *     AIGuard.ContentPart.imageUrl("https://example.com/image.jpg")
+   * ));
+   *
    * // Assistant response with tool calls
    * var assistantWithTools = AIGuard.Message.assistant(
    *     AIGuard.ToolCall.toolCall("call_123", "get_weather", "{\"location\": \"New York\"}")
@@ -208,7 +373,8 @@ public List<String> getTags() {
   public static class Message {
 
     private final String role;
-    private final String content;
+    @Nullable private final String content;
+    @Nullable private final List<ContentPart> contentParts;
     private final List<ToolCall> toolCalls;
     private final String toolCallId;
 
@@ -223,12 +389,41 @@ public static class Message {
      *     response
      */
     public Message(
-        final String role,
-        final String content,
-        final List<ToolCall> toolCalls,
-        final String toolCallId) {
+        @Nonnull final String role,
+        @Nullable final String content,
+        @Nullable final List<ToolCall> toolCalls,
+        @Nullable final String toolCallId) {
       this.role = role;
       this.content = content;
+      this.contentParts = null;
+      this.toolCalls = toolCalls;
+      this.toolCallId = toolCallId;
+    }
+
+    /**
+     * Creates a new message with content parts (text and/or images).
+     *
+     * @param role the role of the message sender
+     * @param contentParts list of content parts
+     * @param toolCalls list of tool calls, or null
+     * @param toolCallId the tool call ID this message responds to, or null
+     * @throws IllegalArgumentException if contentParts contains null elements
+     */
+    public Message(
+        @Nonnull final String role,
+        @Nonnull final List<ContentPart> contentParts,
+        @Nullable final List<ToolCall> toolCalls,
+        @Nullable final String toolCallId) {
+      this.role = role;
+      this.content = null;
+
+      for (final ContentPart part : contentParts) {
+        if (part == null) {
+          throw new IllegalArgumentException("contentParts must not contain null elements");
+        }
+      }
+
+      this.contentParts = Collections.unmodifiableList(contentParts);
       this.toolCalls = toolCalls;
       this.toolCallId = toolCallId;
     }
@@ -245,12 +440,24 @@ public String getRole() {
     /**
      * Returns the text content of the message.
      *
-     * @return the message content, or null for assistant messages with only tool calls
+     * @return the message content, or null if using content parts or for assistant messages with
+     *     only tool calls
      */
+    @Nullable
     public String getContent() {
       return content;
     }
 
+    /**
+     * Returns the content parts of the message.
+     *
+     * @return the content parts (text and images), or null if using plain text content
+     */
+    @Nullable
+    public List<ContentPart> getContentParts() {
+      return contentParts;
+    }
+
     /**
      * Returns the list of tool calls associated with this message.
      *
@@ -276,10 +483,24 @@ public String getToolCallId() {
      * @param content the text content of the message
      * @return a new Message instance
      */
-    public static Message message(final String role, final String content) {
+    @Nonnull
+    public static Message message(@Nonnull final String role, @Nonnull final String content) {
       return new Message(role, content, null, null);
     }
 
+    /**
+     * Creates a message with specified role and content parts (text and/or images).
+     *
+     * @param role the role of the message sender (e.g., "user", "system")
+     * @param contentParts list of content parts (text and/or images)
+     * @return a new Message instance
+     */
+    @Nonnull
+    public static Message message(
+        @Nonnull final String role, @Nonnull final List<ContentPart> contentParts) {
+      return new Message(role, contentParts, null, null);
+    }
+
     /**
      * Creates a tool response message.
      *
@@ -297,8 +518,9 @@ public static Message tool(final String toolCallId, final String content) {
      * @param toolCalls the tool calls the assistant wants to make
      * @return a new Message instance with role "assistant" and no text content
      */
-    public static Message assistant(final ToolCall... toolCalls) {
-      return new Message("assistant", null, Arrays.asList(toolCalls), null);
+    @Nonnull
+    public static Message assistant(@Nonnull final ToolCall... toolCalls) {
+      return new Message("assistant", (String) null, Arrays.asList(toolCalls), null);
     }
   }
 
diff --git a/dd-trace-api/src/test/groovy/datadog/trace/api/aiguard/AIGuardTest.groovy b/dd-trace-api/src/test/groovy/datadog/trace/api/aiguard/AIGuardTest.groovy
index f987cb307b0..6e9673c074b 100644
--- a/dd-trace-api/src/test/groovy/datadog/trace/api/aiguard/AIGuardTest.groovy
+++ b/dd-trace-api/src/test/groovy/datadog/trace/api/aiguard/AIGuardTest.groovy
@@ -69,4 +69,109 @@ class AIGuardTest extends Specification {
     eval.action == ALLOW
     eval.reason == 'AI Guard is not enabled'
   }
+
+  void 'test ImageURL creation'() {
+    when:
+    final imageUrl = new AIGuard.ImageURL('https://example.com/image.jpg')
+
+    then:
+    imageUrl.url == 'https://example.com/image.jpg'
+  }
+
+  void 'test ContentPart.text factory'() {
+    when:
+    final part = AIGuard.ContentPart.text('Hello world')
+
+    then:
+    part.type == AIGuard.ContentPart.Type.TEXT
+    part.text == 'Hello world'
+    part.imageUrl == null
+  }
+
+  void 'test ContentPart.imageUrl from String factory'() {
+    when:
+    final part = AIGuard.ContentPart.imageUrl('https://example.com/image.jpg')
+
+    then:
+    part.type == AIGuard.ContentPart.Type.IMAGE_URL
+    part.text == null
+    part.imageUrl != null
+    part.imageUrl.url == 'https://example.com/image.jpg'
+  }
+
+  void 'test Message with contentParts'() {
+    when:
+    final message = AIGuard.Message.message('user', [
+      AIGuard.ContentPart.text('Describe this image:'),
+      AIGuard.ContentPart.imageUrl('https://example.com/image.jpg')
+    ])
+
+    then:
+    message.role == 'user'
+    message.content == null
+    message.contentParts != null
+    message.contentParts.size() == 2
+    message.contentParts[0].type == AIGuard.ContentPart.Type.TEXT
+    message.contentParts[0].text == 'Describe this image:'
+    message.contentParts[1].type == AIGuard.ContentPart.Type.IMAGE_URL
+    message.contentParts[1].imageUrl.url == 'https://example.com/image.jpg'
+  }
+
+  void 'test Message with plain content returns null contentParts'() {
+    when:
+    final message = AIGuard.Message.message('user', 'Hello')
+
+    then:
+    message.content == 'Hello'
+    message.contentParts == null
+  }
+
+  void 'test Message with contentParts returns null content'() {
+    when:
+    final message = AIGuard.Message.message('user', [AIGuard.ContentPart.text('Hello')])
+
+    then:
+    message.content == null
+    message.contentParts != null
+  }
+
+
+
+  void 'test Message validation allows null content for assistant with tool calls'() {
+    when:
+    final message = AIGuard.Message.assistant(
+      AIGuard.ToolCall.toolCall('1', 'test', '{}')
+      )
+
+    then:
+    message.role == 'assistant'
+    message.content == null
+    message.contentParts == null
+    message.toolCalls != null
+  }
+
+  void 'test Message allows empty contentParts list'() {
+    when:
+    def message = new AIGuard.Message('user', [], null, null)
+
+    then:
+    message.contentParts != null
+    message.contentParts.isEmpty()
+  }
+
+  void 'test ContentPart validation fails for TEXT without text'() {
+    when:
+    new AIGuard.ContentPart(AIGuard.ContentPart.Type.TEXT, null, null)
+
+    then:
+    thrown(IllegalArgumentException)
+  }
+
+  void 'test ContentPart validation fails for IMAGE_URL without imageUrl'() {
+    when:
+    new AIGuard.ContentPart(AIGuard.ContentPart.Type.IMAGE_URL, null, null)
+
+    then:
+    thrown(IllegalArgumentException)
+  }
 }