You can control Aximmetry via HTTP commands sent with the POST method.

For this you have to start the Composer as administrator and with the /server command line switch.
In the Startup Configuration you'll find a new Network Settings page. There you can select the port you want to control Aximmetry through.

In most cases you can leave it on default.

The commands must be sent to the URL:
http://ip_of_the_Aximmetry_machine:Composer_HTTP_port/AximmetryComposer
for e.g.
http://localhost:21463/AximmetryComposer

The commands themselves are presented in XML format. The most important command is ComposerSetPinValueAction with which you set the value of any pins of any modules within your compound. It look like this:

<action type="ComposerSetPinValueAction" Module="module_path" Pin="pin_name" Value="pin_value" />

For e.g. suppose you want to change between several texts to display on the screen in a compound like this:

To select the text number 7 you have to send the following:

<action type="ComposerSetPinValueAction" Module="Root\Switch Text" Pin="Selected" Value="7" />

In practice it is easier to expose all your pins you want to control on the Root level, so that you don't have to deal with module paths, for e.g.:

In this case you can use the following command instead:

<action type="ComposerSetPinValueAction" Module="Root" Pin="TextNo" Value="7" />

Of course you can choose to set the text itself directly:

<action type="ComposerSetPinValueAction" Module="Root" Pin="Display Text" Value="The text I want to display" />

You can also address control board buttons directly. For that you can use the ComposerCtrBoardPressButtonAction command:

<action type="ComposerCtrBoardPressButtonAction" Module="panel_path" Button="button_name" />

It simulates pressing a button on the panel.
For e.g. suppose you want to switch camera within the standard VirtualCam control board.

panel_path is very similar to module_path, but beside of compound names it can also refer to control board names.
In this case we have the VirtualCam_A-B_Preview_3-Cam compound, within that we need the CAMERAS control board, and within that the SELECT CAMERA panel.
For e.g. we want to "press" the CAM 2 button. All of that have to be written like this:

<action type="ComposerCtrBoardPressButtonAction" Module="Root\VirtualCam_A-B_Preview_3-Cam\CAMERAS\SELECT CAMERA" Button="CAM 2" />

If you have a logical ON/OFF button, pressing it will always toggle the between ON and OFF. But you might want to explicitly specify which state it should be in. For this purpose there is another command named ComposerCtrBoardSetButtonAction.

<action type="ComposerCtrBoardPressButtonAction" Module="panel_path" Button="button_name"  State="True/False" />

For e.g. let's turn the streaming on on the same control board:

<action type="ComposerCtrBoardSetButtonAction" Module="Root\VirtualCam_A-B_Preview_3-Cam\CAMERAS\STREAMING" Button="#On" State="True" />

(In this case the button contains an icon, but that is achieved by using the special name #On, and this is the name you have to specify for the command.)