ComfyUI Extension: ComfyUI-Brekel

Authored by Brekel

Created

Updated

18 stars

Nodes to enhance & streamline prompts. Enhance using local LLM within ComfyUI, generate using random lines from text files, or randomly select text file prompts

Custom Nodes (0)

    README

    Brekel's Custom Nodes for ComfyUI

    A collection of custom nodes for ComfyUI designed to enhance and streamline your prompt engineering workflow.
    These nodes provide tools for generating, combining, enhancing, and selecting prompts dynamically.

    <img src="images/Screenshot_flux.jpg">

    Table of Contents

    📦 Installation

    Recommended: ComfyUI Manager

    1. Open the ComfyUI Manager.
    2. Click on Install Custom Nodes.
    3. Search for Brekel or the name of one of the nodes.
    4. Click Install on the desired node pack.
    5. Restart ComfyUI.

    The manager will automatically handle the installation and download any required dependencies for the Prompt Enhancer (LLM) node.

    Manual Installation (Git)

    1. Navigate to your ComfyUI custom nodes directory:

      cd ComfyUI/custom_nodes/

    2. Clone this repository:

      git clone https://github.com/brekel/ComfyUI-Brekel.git

    3. Install the required Python packages for the Prompt Enhancer (LLM) node:

      cd ComfyUI-Brekel
pip install -r requirements.txt

    4. Restart ComfyUI.

    📃 Brekel Prompt Enhancer (LLM)

    This node uses a local Large Language Model (LLM) to creatively rewrite and enhance a simple input prompt into a more detailed and descriptive one.
    No need for 3rd party apps or cloud API calls, all from within ComfyUI <img src="images/Screenshot_prompt_enhance.png">

    Setup Requirements

    LLM Models: This node uses LLM models from the ComfyUI/models/LLM/ directory.
    The node expects models in the standard Hugging Face format (i.e., the folder should contain config.json, model.safetensors, etc.).

    Some LLM model suggestions: | Model name / link | Model Size | |:---------------------------------------------------------------------------------------------|:-----------| | Llama-3.2-1B-Instruct | 1B | | Llama-3.2-3B-Instruct | 3B | | Llama-3.1-8B-Uncensored | 8B | | Qwen2-0.5B-Instruct | 0.5B | | Qwen2-1.5B-Instruct | 1.5B |

    To install a model:

    • Open a command prompt in the ComfyUI/models/LLM/ directory.
    • On the HuggingFace page click the three dots icon (just left to the Train button) and select Clone Repository.
    • Copy the command that starts with: git clone https://.......
    • Paste and execute this command in your command prompt.
    • You may need to run the git lfs install first to install Large File Support.
    • Some models (like Llama) may need you to request access first from the Model card page, approval make take while

    System Prompts: The node reads "system prompts" (instructions for the LLM) from .txt files located in ComfyUI/custom_nodes/ComfyUI-Brekel/prompt_enhancer/.
    This folder is included with the installation and contains default system prompts for text-to-image and text-to-video. You can edit these or add your own .txt files to create custom LLM behaviors. (the node will automatically add a line to the prompt to ask the LLM to respect the max_length)

    Inputs

    | Parameter | Type | Description | |:------------------- |:-------- |:----------------------------------------------------------------------------------------------------------------------------------------------- | | prompt | STRING | The simple, original prompt you want to enhance. | | prefix | STRING | Prefix to prepend at the start of the prompt, for example to add your Lora trigger word(s). | | model_name | Dropdown | The LLM to use. The list is populated from your ComfyUI/models/LLM/ folder. | | quantization | Dropdown | VRAM saving technique. 16-bit is highest quality, while 8-bit and 4-bit use significantly less VRAM at a slight cost to precision. | | memory_management | Dropdown | How to handle the model after use: Keep in VRAM (fastest for re-runs), Offload to CPU (saves VRAM), Unload completely (frees all memory). | | system_prompt | Dropdown | The instruction template for the LLM, loaded from the prompt_enhancer folder. | | max_length | INT | The maximum number of new tokens (words/characters) the LLM can generate. | | creativity | FLOAT | Controls the LLM's temperature. 0.0 is deterministic, while higher values (e.g., 0.8) produce more creative and varied outputs. | | seed | INT | The seed for the LLM's random generation process. 0 means random. | | postfix | STRING | Postfix to append at the end of the prompt, for example to add your Lora trigger word(s). | <br>

    📃Brekel Auto Prompt Generator

    This node constructs a complete prompt by combining up to four randomly selected lines from different text files with a optional prefix/postfix. It's a powerful tool for creating complex, semi-randomized prompts while still allowing full control by customizing the text file contents. <img src="images/Screenshot_auto_prompt_generator.png">

    How to Use

    1. This node reads from .txt files located in the ComfyUI/custom_nodes/ComfyUI-Brekel/auto_prompt_generator/ folder, which is included with the installation.
    2. Populate this folder with your own .txt files or edit the existing examples. Each file should contain a list of items, one per line (e.g., a file for styles, another for artists, another for lighting types). You can of course add additional text files. (Refresn Node Definitions to update the node with new text file entries)
    3. In ComfyUI, use the random_line_file dropdowns to select the files you want to draw from. Selecting "None" will skip that slot.
    4. The node will pick one random line from each selected file and combine them with your prefix and postfix using the specified delimiter.
    5. Alternatively, set use_static_prompt to "true" to bypass the random generation and use the text from the static_prompt input instead.

    Inputs

    | Parameter | Type | Description | |:--------------------- |:-------- |:---------------------------------------------------------------------------------------------------------------- | | prefix | STRING | Text that will always appear at the beginning of the prompt. | | random_line_file1-4 | Dropdown | Select a .txt file from the auto_prompt_generator folder. The node will pick one random line from this file. | | seed | INT | The seed used for choosing the random lines from the files. | | mode | Dropdown | Random Prompt: Selects random lines from the files. Static Prompt: Uses the use_static_prompt. | | static_prompt | STRING | A fixed prompt to use when mode is set to Static Prompt. | | postfix | STRING | Text that will always appear at the end of the prompt. | | delimiter | STRING | The character(s) used to join the different prompt parts (e.g., ", " or "\n" for a newline). | | clean_whitespace | Dropdown | true: Removes any leading/trailing whitespace from the final prompt. | <br>

    📃 Brekel Prompt Chooser

    This node allows you to select a text prompt from a folder of .txt files, either randomly or by a specific index.
    It's perfect for workflows where you want to iterate through a predefined list prompts. <img src="images/Screenshot_prompt_chooser.png">

    How to Use

    1. This node uses the ComfyUI/custom_nodes/ComfyUI-Brekel/prompt_chooser/ folder, which is included with the installation.
    2. Place your .txt files inside this folder. Each file should contain a single prompt.
      • Example: cat.txt could contain "A cat wearing a wizard hat".
      • Example: dog.txt could contain "A dog riding a skateboard".
      • Add as many of your own files and/or delete the example files as needed.
    3. In ComfyUI, set the folder_path to this directory (it should be the default).
    4. Choose your selection_mode:
      • Random: Uses the seed to pick a random file. A seed of 0 will be different each time.
      • Index: Picks a file based on its alphabetical order in the folder. The index will wrap around if it's larger than the number of files.

    Inputs

    | Parameter | Type | Description | |:---------------- |:-------- |:------------------------------------------------------------------------------------------------------------- | | folder_path | STRING | The full path to the folder containing your .txt prompt files. | | selection_mode | Dropdown | Random: Selects a file randomly based on the seed. Index: Selects a specific file by its numerical index. | | seed | INT | The seed for the random number generator when in Random mode. | | file_index | INT | The index of the file to choose (alphabetically sorted) when in Index mode. | <br>

    📝 Author

    These nodes were created by Brekel.