All eight- and nine-dimensional string vacua from junctions

String and 5-brane junctions are shown to succinctly classify all known 8d ${\cal N}$=1 string vacua. This requires an extension of the description for ordinary $[p,q]$-7-branes consistently include O7$^+$-planes, which then naturally encodes dynamics $\mathfrak{sp}_n$ gauge algebras, including their higher-form center symmetries. Central this analysis loop junctions, i.e., strings/5-branes encircle stacks 7-branes O7$^+$'s. Loop further signal appearance affine symmetries emergent 9d descriptions at moduli space's boundaries. Such limits reproduce vacua, two disconnected rank (1,1) components.