Mpi Prompt List

This is the node the whole ComfyUi-MpiNodes prompt system is built around. Mpi Prompt List is the wildcard equivalent - it holds a set of options (one per line) and, when a _title_ token in a MpiPromptProcessor template asks for it, it hands over a selection. Add probability, blocking rules, chaining, and seed control and you've got a prompt-randomization engine that actually scales.

If you've ever used A1111-style wildcard prompts - __clothes__ style tokens that pick a random line from a text file - this is that idea, but as typed, composable nodes. The dynamic-prompt pattern is still very much alive in the community; this pack just industrializes it with probability gates and chaining instead of raw randomness.

How it works

You give the list a title - that's the _title_ token that triggers it in a Prompt Processor. Then:

• options - each line is one selectable option.
• prefix / suffix - text prepended/appended to every option. Suffix goes at the very end, after any negative text, so read the tooltip before using it there.
• blocks - comma-separated titles of other lists this one suppresses. If list A blocks list B, selecting from A makes B sit out. That's how you stop "beach" from appearing with "snowsuit."
• probability - the chance this list fires at all. 0.0 always bypasses, 1.0 always passes, 0.5 is a coin flip. This is the "sometimes include this, sometimes not" control.
• seed - drives both probability and the option ordering. Same seed, same pick.
• random - when disabled, the list order doesn't shuffle.

Two advanced widgets trip people up: amount (if > 0, outputs that many items as one comma-joined option) and specific_item (0 bypasses the list entirely, ≥ 1 forces that single item). Both are documented as stopping _multipliers_x2_ and _pickers_3_ from working - so read the tooltips before you stack them.

The optional opt_chained_list input is how lists chain: it appends this list onto an existing chain, letting one node build a multi-list pipeline. opt_override accepts a PROMPT_OVR from MpiPromptOverride to force custom options.

Outputs

Four of them: prompt_list (the PROMPT_LST that feeds a Processor or a chain), seed (the seed after this list ran, so downstream randomness stays coordinated), boolean (whether the list passed its probability gate), and selected_options (the STRING of what was actually chosen - handy for display or logging).

Installing it

cd ComfyUI/custom_nodes
git clone https://github.com/MadPonyInteractive/ComfyUi-MpiNodes

Restart ComfyUI, or use ComfyUI Manager → search ComfyUi-MpiNodes. No pip deps, no models. The pack is AGPL-3.0 from v1.2.7 (MIT through 1.2.6).

The honest take

The probability gate is the killer feature and the thing wildcard-file systems never give you cleanly. "70% chance of rain, if rain then dark sky and umbrella, and never snow with beach" is a graph of three Prompt Lists with blocks and probabilities - genuinely expressive. Where people get burned: the suffix placement (it lands after negative content), and stacking amount/specific_item with token multipliers. When a prompt comes out missing a section, check the boolean output - a list that rolled under its probability isn't broken, it just chose not to run.