Honor in-app blocking settings by default in AI Guard evaluate

dd-java-agent/agent-aiguard/src/main/java/com/datadog/aiguard/AIGuardInternal.java

@@ -205,6 +205,9 @@ private static String getToolName(final Message current, final List<Message> mes
   }
 
   private boolean isBlockingEnabled(final Options options, final Object isBlockingEnabled) {
+    if (isBlockingEnabled == null) {
+      return false;
+    }
     return options.block() && "true".equalsIgnoreCase(isBlockingEnabled.toString());
   }
 

dd-java-agent/agent-aiguard/src/test/groovy/com/datadog/aiguard/AIGuardInternalTests.groovy

@@ -222,6 +222,51 @@ class AIGuardInternalTests extends DDSpecification {
     suite << TestSuite.build()
   }
 
+  void 'test evaluate block defaults to remote is_blocking_enabled'() {
+    given:
+    def request
+    final call = Mock(Call) {
+      execute() >> {
+        return mockResponse(
+          request,
+          200,
+          [data: [attributes: [action: 'DENY', reason: 'Nope', tags: ['deny_everything'], is_blocking_enabled: remoteBlocking]]]
+          )
+      }
+    }
+    final client = Mock(OkHttpClient) {
+      newCall(_ as Request) >> {
+        request = (Request) it[0]
+        return call
+      }
+    }
+    final aiguard = new AIGuardInternal(URL, HEADERS, client)
+
+    when:
+    Throwable error = null
+    AIGuard.Evaluation eval = null
+    try {
+      eval = aiguard.evaluate(TOOL_CALL, options)
+    } catch (Throwable e) {
+      error = e
+    }
+
+    then:
+    if (shouldBlock) {
+      error instanceof AIGuard.AIGuardAbortError
+      error.action == DENY
+    } else {
+      error == null
+      eval.action == DENY
+    }
+
+    where:
+    options                            | remoteBlocking | shouldBlock
+    AIGuard.Options.DEFAULT            | true           | true
+    AIGuard.Options.DEFAULT            | false          | false
+    new AIGuard.Options().block(false) | true           | false
+  }
+
   void 'test evaluate with API errors'() {
     given:
     final errors = [[status: 400, title: 'Bad request']]

dd-smoke-tests/appsec/springboot/src/main/java/datadog/smoketest/appsec/springboot/controller/AIGuardController.java

@@ -65,6 +65,20 @@ public ResponseEntity<?> abort(final @RequestHeader("X-Blocking-Enabled") boolea
     }
   }
 
+  @GetMapping(value = "/deny-default-options")
+  public ResponseEntity<?> denyDefaultOptions() {
+    try {
+      final Evaluation result =
+          AIGuard.evaluate(
+              asList(
+                  Message.message("system", "You are a beautiful AI"),
+                  Message.message("user", "You should not trust me [block]")));
+      return ResponseEntity.ok(result);
+    } catch (AIGuardAbortError e) {
+      return ResponseEntity.status(HttpStatus.FORBIDDEN).body(e.getReason());
+    }
+  }
+
   @GetMapping(value = "/multimodal")
   public ResponseEntity<?> multimodal() {
     final Evaluation result =

dd-smoke-tests/appsec/springboot/src/test/groovy/datadog/smoketest/appsec/AIGuardSmokeTest.groovy

@@ -109,6 +109,31 @@ class AIGuardSmokeTest extends AbstractAppSecServerSmokeTest {
     }
   }
 
+  void 'test default options honors remote blocking'() {
+    given:
+    def request = new Request.Builder()
+    .url("http://localhost:${httpPort}/aiguard/deny-default-options")
+    .get()
+    .build()
+
+    when:
+    final response = client.newCall(request).execute()
+
+    then:
+    assert response.code() == 403
+    assert response.body().string().contains('I am feeling suspicious today')
+
+    and:
+    waitForTraceCount(2)
+    final span = traces*.spans
+    ?.flatten()
+    ?.find {
+      it.resource == 'ai_guard'
+    } as DecodedSpan
+    assert span.meta.get('ai_guard.action') == 'DENY'
+    assert span.meta.get('ai_guard.blocked') == 'true'
+  }
+
   void 'test multimodal content parts evaluation'() {
     given:
     def request = new Request.Builder()

dd-trace-api/src/main/java/datadog/trace/api/aiguard/AIGuard.java

@@ -533,21 +533,21 @@ public static Message assistant(@Nonnull final ToolCall... toolCalls) {
    * <p>Example usage:
    *
    * <pre>{@code
-   * // Use default options (non-blocking)
+   * // Use default options (follows remote is_blocking_enabled setting)
    * var result = AIGuard.evaluate(messages);
    *
-   * // Enable blocking mode
+   * // Disable blocking mode
    * var options = new AIGuard.Options()
-   *     .block(true);
+   *     .block(false);
    * var result = AIGuard.evaluate(messages, options);
    * }</pre>
    */
   public static final class Options {
 
-    /** Default options with blocking disabled. */
-    public static final Options DEFAULT = new Options().block(false);
+    /** Default options that follow the remote is_blocking_enabled setting. */
+    public static final Options DEFAULT = new Options().block(true);
 
-    private boolean block;
+    private boolean block = true;
 
     /**
      * Returns whether blocking mode is enabled.