Runtime Toggle String Join (2)

The plain Toggle String Join nodes are queue snapshots: flip a toggle, queue, and the jobs already in line ignore you. Runtime Toggle String Join (2) is the same idea with the opposite philosophy - the toggle stays live, and each job reads the latest state at the moment it executes. Flip a switch while a queue is draining and the next image picks it up.

That's the one-sentence pitch, and it's worth sitting with for a second, because it's genuinely unusual. The pack's intended use is "long, pre-queued generation runs": queue a batch of jobs in advance, keep tweaking the prompt composition between jobs, and have the changes apply without re-queueing. This two-input version is the minimal way to test that workflow before you scale up to 10 sockets.

How the live state actually works

Under the hood there's a small state store on the ComfyUI server. When you click a toggle, the node's frontend sends the new mode and mask to a server route (/string_join_tools/runtime_state) keyed by a state_key. When the node executes, it reads that server-side state instead of trusting what was captured at queue time, then joins only the currently enabled non-empty strings. If live state isn't available - say, after a restart - it falls back to the saved queue-time values. The node even shows a subtle amber tint and a LIVE status so you know you're looking at a runtime node and not a snapshot one.

Two implementation details are worth knowing because they explain behavior you'll observe:

• It can't be cached. The node bakes a monotonically increasing revision number into its IS_CHANGED result, so changing a toggle invalidates the cached join and forces downstream processing to redo. Toggle something, and the next execution reflects it.
• Timing is "the next image onward." A change affects jobs whose Runtime Toggle Join hasn't executed yet. For normal image workflows, treat that as: the currently generating image finishes, then the change applies.

What you set

• mode - multiple (each input independent) or single (zero or one enabled).
• Per-row ON/OFF buttons - the actual control surface.
• separator - default ", ", with \n, \r\n, \t, \\ escapes.
• state_key - normally auto-generated per node and best left alone. Set it manually only if you want two copies to control the same live state. The README's rule of thumb: use one active browser tab per workflow, since live state is shared by key.
• text_1, text_2 - optional STRING sockets. Output is one text STRING.

Installing it

ComfyUI Manager: search "String Join Tools" or "ComfyUI-StringJoinTools". Or:

cd ComfyUI/custom_nodes
git clone https://github.com/ruminar/ComfyUI-StringJoinTools

Restart and refresh. No Python dependencies, no models. Under String Join Tools.

The honest caveats

Live state lives in server memory and dies on a ComfyUI restart - a restart means the fallback saved values take over until you touch a toggle again. And if you're not running a queue, the live vs snapshot distinction barely matters: you'll get the same result either way, so this node's complexity only pays for itself on long runs. Keep that in mind before you reach for it; the snapshot variants are simpler and are the right call for most one-shot work.