Prompt Library

Prompt_Library is the flagship of this pack and the answer to a very specific kind of mess: you have a hundred hand-tuned prompts in scattered .txt files, and you're copy-pasting them into ComfyUI one at a time. This node turns a folder of plain text files into a dropdown-driven prompt database, with positive/negative separation built in.

It is not a fancy visual library with colors and search and tags. It's deliberately plain - text files, a dropdown, an index - which is both its strength (your prompts stay editable in any editor, and version-controllable) and its limit (you organize by folder, or not at all). If that sounds like exactly what you wanted, this is your node.

How it works

Everything lives in ComfyUI/models/prompts/. Inside it you make category folders, and inside those you drop *.txt files. Each .txt file is a little prompt library with this syntax:

• An empty line separates one prompt from the next.
• A line starting with ### is a title or note - ignored in output.
• --- (three or more hyphens) splits positive from negative, anywhere in the text.

So a file looks like this (this is literally the shipped demo):

### Forest Meadow
high quality, forest, meadow, forest clearing, sunlight and shadows --- bad quality, rainy, bad lighting

### Flower Meadow
flowers, meadow, beautiful, sunlight and shadows, high contrast --- bad lighting, rainy, cold

The project dropdown lists every file as Category/Name. The index input picks which prompt inside that file you want (1-based). Turn on randomize_index and it draws one at random instead. The node even ships two UI buttons - 📁 Prompts Folder opens the folder in your file manager, 🔄 Refresh List rebuilds the dropdown after you add files.

The inputs that matter

• project - the dropdown of Category/Name entries. The whole node is built around this.
• index - which prompt in the file (1–999). Wraps around if you go past the end.
• randomize_index - off: always show that index. on: pick randomly.
• random_seed - -1 (default) means time-based random, so every run picks differently; set a concrete number to make the random pick reproducible.

Outputs

• double_prompt - the full positive\n---\nnegative string.
• positive_prompt / negative_prompt - the two halves on their own, so you can route them separately.

Feed double_prompt into Double_Prompt_Encode and you've got conditioning.

How to install it

Install the pack via ComfyUI Manager (search ComfyUI-Prompt_Library) or:

cd ComfyUI/custom_nodes
git clone https://github.com/hexxacubic/ComfyUI-Prompt_Library

Restart ComfyUI. No Python dependencies, no model downloads. But - the README explicitly says to copy the models folder from the repository into your ComfyUI install to get the demo project files. On the cloned repo that's models/prompts/City/Environments.txt and models/prompts/Fantasy/Forest.txt; copy them so they land at ComfyUI/models/prompts/.... Without that step, the dropdown just says No projects found.

Where people get burned

That "No projects found" dropdown is the #1 complaint, and it's almost always the missing folder or an empty one - click the folder button and look. Second: the files are read as UTF-8, so save your .txt with UTF-8 encoding or accented characters garble. Third: the dropdown list is only built when the node initializes or you hit Refresh List - new files don't appear until you do.

One naming warning before you search for this thing: "prompt library" is one of the most overloaded names in the ecosystem, and ComfyUI Manager surfaces several different packs with similar titles - including a much bigger visual-library node pack that shares the display name "Prompt Library". Make sure the one you install is hexxacubic/ComfyUI-Prompt_Library. Different pack, different node, different folder layout.