The RMB mouse button works with inputAction just fine:

oneachframe {hintsilent str [inputAction "holdbreath"]}

However if bound to user action, inputAction fails to detect mouse button input:

1. bind sec mouse button to User Action 1
2. execute

oneachframe {hintsilent str [inputAction "user1"]}

3. no effect

Edited the title

"holdbreath" is detected for me, but only because its bound to RMB hold. Even when using your code, binding RMB click to holdBreath, or any other action is still undetected.

That's true, I just tested. So the issue is with mouse button hold.

1. open User Action 1 bindings
2. press and hold RMB to add mouse button binding
3. execute

oneachframe {hintsilent str [inputAction "user1"]}

4. it Works

do the same as above but add normal button press instead of hold
it doesnt work.

Not sure if this is related, but I've noticed when binding RMB to a control it detects it as Hold Sec. Mouse Button for a half-second then switching to normal Sec. Mouse Button. Issue does not occur when binding Sec. Mouse button with a modifier (Ctrl, Shift, Alt).

Tested on stable branch with two different mice and no addons.

I've also noticed this behavior, Tholozor.

running the following code
`

		systemChat str (inputAction 'optics');
		systemChat str (inputAction 'opticsTemp');
		systemChat str (inputAction 'opticsMode');

`
will always print 0 for all 3, when the bind is RMB (right mouse button).
However, when binding to keyboard, like "H", inputAction works and prints 1

Looks very much like a "won't fix"
always handling mouse clicks as mouse hold's was done intentionally because that makes more sense to the average player

rev 148496 added https://community.bistudio.com/wiki/inputMouse