Prompt Slot Picker

Of all the nodes in the ComfyUI Orchestration Toolkit, this is the one that looks least like it's doing anything. It's a small box with a manifest wire in, a number, and two text outputs out. But it's the node that makes the whole parallel prompt-testing pipeline work, because it's the one that decides which prompt each branch of your workflow actually renders.

Here's the setup it lives in. A PromptOrchestrator holds your list of prompts. A Prompt Distributor turns that list into a shared routing table called a Prompt Manifest - ten slots, each holding one positive/negative pair. Now you build up to ten branches of the graph, and drop one Prompt Slot Picker into each branch. Slot 1 on the picker in branch A, slot 2 on the picker in branch B, and so on. Each branch quietly draws a different line from the list.

How it works

The picker reads the manifest it's handed and looks up its slot number. Slot numbering is 1-based and positional - slot 1 is the first prompt in the list, slot 2 the second, and so on, in the same order your list was typed. If that slot is active, the node hands back the positive and negative prompt strings for it. If the slot is inactive - because the Distributor only had, say, three prompts but you asked for eight branches - it returns an ExecutionBlocker instead. That's ComfyUI's official "don't run anything downstream of me" object, so an empty slot doesn't error or freeze: that branch of the graph simply never executes. It's data-driven muting, and it's why a prompt list shorter than your branch count just works instead of producing a wall of errors.

The inputs and outputs that matter

Only two inputs, and only slot is yours to touch:

• prompt_manifest - connect this to the Prompt Manifest output of your Prompt Distributor. Same wire your sibling pickers and your downstream Prompt Collector use.
• slot (INT, default 1, range 1–10) - which prompt in the list this branch draws. Give every branch a different number.

Outputs are Positive Prompt and Negative Prompt, both plain strings - wire them into the positive and negative text inputs of that branch's CLIP encoder, and you're done. Positive-only lists arrive with an empty negative string, which is exactly what CLIP Text Encode expects.

Common issues

If a branch does nothing and you expected it to produce an image, the usual cause is that its slot number is higher than the number of prompts the Distributor actually received - so that slot is inactive and the branch is deliberately blocked. Drop the slot number, or feed the Distributor more prompts. The second classic mistake is wiring pickers to different manifests than the rest of the branch - every picker and the Collector must come from the same Distributor, or the branch draws a prompt from a list that has nothing to do with the images next to it. Both branches downstream of a picker get the same pair, so if you wired the same picker to two branches you'll render the same prompt twice; that's a wiring error, not a node error.

Installation

Part of the ComfyUI Orchestration Toolkit - install once, get every node in the pack. Via ComfyUI Manager search for "Orchestration Toolkit" (publisher flows-and-frames), or:

cd ComfyUI/custom_nodes
git clone https://github.com/flows-and-frames/ComfyUI-Orchestration-Toolkit.git

Restart ComfyUI afterwards. No extra dependencies, no model files, Python 3.10+ required. The pack is genuinely new (first release September 2026), so it has none of the battle-tested community lore an rgthree-class pack has built up - you're an early adopter, which is fine, just know that's the stage it's at.