Enable simple tracer standby in dev profile

core/camel-main/src/main/java/org/apache/camel/main/ProfileConfigurer.java

@@ -49,6 +49,9 @@ public static void configureMain(CamelContext camelContext, String profile, Main
             if (!enabled) {
                 config.tracerConfig().withStandby(true);
             }
+            if (!config.isTracing()) {
+                config.setTracingStandby(true);
+            }
         }
 
         if ("dev".equals(profile)) {

core/camel-main/src/test/java/org/apache/camel/main/MainDevProfileTracingStandbyTest.java

@@ -0,0 +1,85 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.camel.main;
+
+import org.apache.camel.CamelContext;
+import org.apache.camel.builder.RouteBuilder;
+import org.apache.camel.spi.Tracer;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class MainDevProfileTracingStandbyTest {
+
+    @Test
+    public void testDevProfileEnablesTracingStandby() {
+        Main main = new Main();
+        main.configure().withProfile("dev");
+
+        main.start();
+        try {
+            CamelContext context = main.getCamelContext();
+            assertTrue(context.isTracingStandby(),
+                    "dev profile should enable tracing standby");
+        } finally {
+            main.stop();
+        }
+    }
+
+    @Test
+    public void testDevProfileTracingCanBeEnabledAtRuntime() throws Exception {
+        Main main = new Main();
+        main.configure().withProfile("dev");
+        main.configure().addRoutesBuilder(new RouteBuilder() {
+            @Override
+            public void configure() {
+                from("direct:start").to("mock:result");
+            }
+        });
+
+        main.start();
+        try {
+            CamelContext context = main.getCamelContext();
+            Tracer tracer = context.getTracer();
+            assertFalse(tracer.isEnabled(),
+                    "tracer should be in standby (not enabled) by default in dev mode");
+
+            tracer.setEnabled(true);
+            assertTrue(tracer.isEnabled(),
+                    "tracer should be enableable at runtime in dev mode");
+        } finally {
+            main.stop();
+        }
+    }
+
+    @Test
+    public void testProdProfileDoesNotEnableTracingStandby() {
+        Main main = new Main();
+        main.configure().withProfile("prod");
+
+        main.start();
+        try {
+            CamelContext context = main.getCamelContext();
+            assertFalse(context.isTracingStandby(),
+                    "prod profile should not enable tracing standby");
+        } finally {
+            main.stop();
+        }
+    }
+
+}

docs/user-manual/modules/ROOT/pages/tracer.adoc

@@ -45,6 +45,9 @@ camel.main.tracing = true
 By default, Camel optimizes and opt-out tracing. Therefore, you would either have to enable tracing from the startup,
 or turn on standby mode, to allow tracing to be enabled later during runtime.
 
+NOTE: When using Camel Main or Camel JBang with the `dev` profile (the default), tracing standby is automatically enabled.
+This means you can toggle tracing on and off at runtime without needing to restart.
+
 To set tracing in standby mode you can do:
 
 [tabs]