> For the complete documentation index, see [llms.txt](https://adidas.gitbook.io/api-guidelines/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://adidas.gitbook.io/api-guidelines/asynchronous-api-guidelines/core-asynchronous-principles/messages/commands.md).

# Commands

A command is a special type of message which represents just an action, something that will change the state of a given system.

* There is a clear expectation about a state change that needs to take place in the future
* When returning a response indicate completion
* Optionally they can include a result in the response
* Very common to see them in orchestration components