> For the complete documentation index, see [llms.txt](https://b-it-bots.gitbook.io/wiki/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://b-it-bots.gitbook.io/wiki/home/_conventions/ros/messages-services-actions.md).

# Creating a new message, service or action

If your package defines its own messages, services or actions you should add them to the corresponding meta-package:

```
./<package_name>_msgs
├── action
│   ├── MyAction.action
├── msg
│   ├── MyMessage.msg
├── srv
│   └── MyService.srv
├── CMakeLists.txt
├── package.xml
└── README.md
```

Depending on the repository you are working on, the meta-package is related to the domain, e.g. `mdr_planning_msgs` or `mdr_navigation_actions`