Set Variable Rack

Here's the problem this node exists to solve: the main Unprompted node is brilliant at templating, but all your dynamic values have to live in one text box. Want the filename from a node, a randomly chosen style tag, a mask, all flowing into the same template? You'd be juggling [set var]...[/set] shortcodes inside string_field and praying it stays readable. Set Variable Rack (class UnpromptedSetRack) is the visual answer - a companion to the Unprompted node that hands values over as actual graph wires instead of typed syntax.

It's a simple idea done simply. The node has 26 inputs, input_a through input_z, and 26 text fields, var_a through var_z. Wire anything into input_x and type a name into var_x, and when the node runs, that value gets stored in the shared Unprompted engine as a variable. Downstream, inside an Unprompted node's string_field, you pull it back with the language's variable syntax - {name} (which is shorthand for [get name]). The two nodes talk to each other through the same engine instance, so ordering in the graph is all that matters; the rack just has to execute before the Unprompted node reads it.

The inputs that matter

• The 26 input_a–input_z ports are wildcard * types - they'll accept a string, an image, a number, whatever you drop in. That any-type looseness is the whole point; it's the same trick other packs use to let one node swallow anything.
• The var_a–var_z fields are the names of those variables. Don't put content in here; put the token you want to reference in your prompt.

That second bullet is the trap, and it's worth spelling out: the defaults are literally var_a, var_b, and so on. If you wire a string into input_a and never touch the name field, you've just created a variable called var_a - which is probably not what you meant. Rename it to character or pose and then use {character} in your template. Took me one confusing workflow to learn this, so consider the warning free.

What comes out

A single STRING output that is always empty. That's not a bug - the rack's real output is the side effect of populating variables. Don't wire it into a CLIP encoder; the actual prompt processing happens in the Unprompted node. Treat this node as a waystation, not a producer.

The catches

Because the rack writes into the same persistent engine the main node uses, variables live on between queues. If a later workflow doesn't overwrite a name, a stale value can quietly leak into your next prompt. The fix is the same one the pack recommends anyway: enable goodbye_routines on the final Unprompted node in your workflow, which clears the shared variables after the run. Also note this node only stores an input when it's actually connected - an unplugged port is ignored, so you don't need to populate all 26.

Installing it

Same pack as the Unprompted node, so you get it either way: ComfyUI Manager (search ComfyUI-Unprompted), or git clone https://github.com/ThereforeGames/ComfyUI-Unprompted into ComfyUI/custom_nodes, then restart. First launch triggers an auto-install of the engine's pinned dependencies (unprompted, opencv-python, nltk, pattern), which is heavy and one-time - the first boot after install takes a minute or two.

Added in pack v0.3.0, the rack is newer than the node it serves and still lightly traveled. For a beginner it's a nice-to-have; for anyone building a big dynamic-prompt workflow with several moving parts, it's the difference between a readable graph and a wall of shortcode soup. If that's you, it's worth the install.