A probe that returns the literal text OK when the AA runtime session is active, and an empty string when it is not. The AA bootstrap (pageOpen in locsess.php) assigns a session object on every normal page render, so during template expansion on a live page this expression effectively always returns OK. It takes no parameters; use it as a quick liveness or context check.
Examples
test[{aabox:}]
Expected[OK]
Actual[OK]
On a live page the AA runtime session is active, so aabox returns the literal text OK. The brackets show the return is exactly two characters with no surrounding whitespace.
test{if:{aabox:}:eq:OK:running:offline}
Expectedrunning
Actualrunning
Compare the aabox result against OK with if. On a live page aabox returns OK, so the comparison matches and the output is running. This is the practical pattern for using aabox as a liveness or context guard.
test{strlen:{aabox:}}
Expected2
Actual2
On a live page aabox returns OK, which is two characters long. In a context with no initialized session it would return an empty string and strlen would be 0.