Awesome climb just right of crack in the center of 2150 wall (Ripped 10c 4" no stars). Living ... belays just off of the tree, Taping Tendons (11c/d) is to right. Direct start to first bolt is 12d. Standard variation is to stem up the crack, reaching over to clip the first bolt, then traversing just right of the bolt to tackle the sequential crux. Don't worry, it may give you a brief rest after this, but it doesn't ever completely let up until you are at the anchors.
Protection
7 bolts to 2 bolt anchor. Stick clip 1st bolt IF doing direct start.
So, how does the 12a version go? I initially tried traversing from the pillar on the left with my hands in pockets at the 2nd bolt (there are 8 or 9 bolts on the route now). Moving up here was desperate, and felt way harder than 12a (harder than the cruxes of several 12+ Gym routes I tried the day before). I finally ended up climbing to the top of the pillar and traversing in with hands in pockets near the 3rd bolt, which felt reasonable, though reachy.
This route, along with all the others on 2150 wall, are VERY sharp (great routes though!), and should probably be avoided on your second day "on" at Shelf.
The harder version (12c/d on the FA) goes straight up at the second bolt instead of going left and then back to the right. Devious, thin and somewhat painful.