Camel CLI - Debugging

The Camel CLI provides built-in debugging capabilities — from Camel’s own route debugger to standard Java debugging. For the full overview, see Camel CLI.

Just type camel tui — the plugin auto-installs on first use. The Camel TUI includes a Spans tab that shows OpenTelemetry traces as a waterfall view — useful for understanding message flow and spotting slow processors.

Camel route debugging

Available since Camel 4.2

Debug Camel routes directly from the terminal:

camel debug hello.yaml

The integration runs in the background while the foreground shell acts as a CLI debugger. The top shows log output, the middle shows the current breakpoint with source context, and the bottom shows the message content:

2023-11-03 18:15:06.715  INFO 33384 --- [           main] g.apache.camel.main.BaseMainSupport :     [Command Line]                 camel.debug.loggingLevel=DEBUG
2023-11-03 18:15:06.715  INFO 33384 --- [           main] g.apache.camel.main.BaseMainSupport :     [Command Line]                 camel.debug.singleStepIncludeStartEnd=true
2023-11-03 18:15:06.787  INFO 33384 --- [           main] mel.cli.connector.LocalCliConnector : Camel CLI enabled (local)
2023-11-03 18:15:06.833  INFO 33384 --- [           main] el.impl.engine.AbstractCamelContext : Apache Camel 4.7.0 (foo) is starting
2023-11-03 18:15:06.906  INFO 33384 --- [           main] g.apache.camel.main.BaseMainSupport : Property-placeholders summary
2023-11-03 18:15:06.906  INFO 33384 --- [           main] g.apache.camel.main.BaseMainSupport :     [application.properties]       my-name=Donald Duck
2023-11-03 18:15:06.924  INFO 33384 --- [           main] el.impl.engine.AbstractCamelContext : Routes startup (started:1)
2023-11-03 18:15:06.924  INFO 33384 --- [           main] el.impl.engine.AbstractCamelContext :     Started route-07a6 (timer://yaml)
2023-11-03 18:15:06.924  INFO 33384 --- [           main] el.impl.engine.AbstractCamelContext : Apache Camel 4.7.0 (foo) started in 91ms (build:0ms init:0ms start:91ms)
2023-11-03 18:15:11.951  INFO 33384 --- [ - timer://yaml] foo.camel.yaml:10                   : Before:

Source: foo.camel.yaml:13                                                         History
--------------------------------------------------------------------------------  ------------------------------------------------------------------------------------------
  10:              - log:                                                         route-07a6/from-c041           (0ms)    4:       uri: timer
  11:                  message: 'Before: ${body}'                                 route-07a6/log1                (1ms)   10:         - log:
  12:                  id: log1
  13: --->         - setProperty:
  14:                  name: myProp
  15:                  expression:
  16:                    constant:
  17:                      expression: '123'
  18:                      id: constant-4004


2023-11-03 18:15:11.951  33384 --- [ thread #4 - timer://yaml]              route-07a6/setProperty-321c :     3 - Breakpoint (4ms)
 Exchange  (DefaultExchange)  InOnly  D48642E54410AF9-0000000000000000
 Message   (DefaultMessage)
 Body      (null)


    Breakpoint suspended. Press ENTER to continue.

Configuring breakpoints

By default, breakpoints are added to every route. Use --breakpoint to target specific nodes. The option supports multiple match styles (comma-separated):

  • Exact or pattern match by node id (wildcard and regex)

  • EIP kind (setHeader, setBody, choice, split, etc.)

  • Source file and/or line number

Examples:

camel debug hello.yaml --breakpoint=setHeader
camel debug hello.yaml --breakpoint=18
camel debug hello.yaml --breakpoint=18,34

Spring Boot route debugging

Available since Camel 4.14

Debug an existing Spring Boot Maven project by pointing at its pom.xml:

camel debug pom.xml

Camel CLI detects camel-spring-boot-bom, builds a fat JAR, and launches it in the background with debugging enabled — the same experience as debugging plain Camel files.

IDE route debugging

The Camel route debugger is available by default via JMX at service:jmx:rmi:///jndi/rmi://localhost:1099/jmxrmi/camel.

Supported IDE plugins: IntelliJ, VS Code, Eclipse Desktop.

When exporting to a Maven project, use the camel.debug Maven profile to include the camel-debug JAR for IDE-based route debugging.

Java debugging

Use --jvm-debug to open a standard Java debug socket (default port 4004):

camel run hello.yaml --jvm-debug
Listening for transport dt_socket at address: 4004

Attach from IntelliJ, VS Code, or Eclipse. Port configuration is described in the JBang Debugging guide.

JBang-level debugging

Use JBang’s --debug flag to debug any CLI command (not just run):

jbang --debug camel@apache/camel run hello.yaml
Listening for transport dt_socket at address: 4004
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