ComfyUI Local — Secure Image Generation

Generate images using your local ComfyUI instance. Designed with security as a priority:

• Server address is configured, not passed as argument — no connecting to arbitrary servers
• Workflows are allowlisted — only files in the workflows/ directory can be used
• No shell injection surface — prompts are passed as JSON, never interpolated into shell commands
• Path traversal blocked — ../ and absolute paths are rejected

Setup

1. Server address: Set the COMFYUI_SERVER_ADDRESS environment variable (e.g., http://192.168.1.10:8188 or http://127.0.0.1:8188).
2. ComfyUI API mode: Ensure "Enable Dev mode" is turned on in your ComfyUI settings.

Usage

Generate an image with a prompt

python3 {skillDir}/scripts/comfy_gen.py --prompt "a serene mountain lake at sunset"

Generate with a specific allowlisted workflow

python3 {skillDir}/scripts/comfy_gen.py --prompt "a cyberpunk cityscape" --workflow z-image-turbo

Generate with custom dimensions

python3 {skillDir}/scripts/comfy_gen.py --prompt "a cat in a spacesuit" --width 768 --height 512

Generate with negative prompt

python3 {skillDir}/scripts/comfy_gen.py --prompt "a portrait photo" --negative "blurry, distorted, low quality"

Available Workflows

Place API-format workflow JSON files in the workflows/ directory. They are automatically available by filename (without .json extension).

The included workflows:

Workflow	Description
z-image-turbo	Fast generation, 10 steps, Euler sampler
z-image-biglove	Higher quality, more steps

Security Design

This skill fixes the three vulnerabilities found in other ComfyUI skills:

1. No arbitrary file reads

The original skill accepted --workflow /any/path/on/disk.json, allowing an agent to read any JSON file on the system. This version only allows workflows from the workflows/ directory within the skill folder. Paths with .., /, or \ are rejected.

2. No arbitrary server connections

The original skill accepted the server address as a command-line argument, allowing connections to any server. This version reads COMFYUI_SERVER_ADDRESS from the environment only. No command-line override.

3. No shell injection

The original skill constructed shell commands with user-provided arguments. This version uses argparse and passes all data as structured JSON over HTTP — no shell interpolation.

How It Works

1. Reads COMFYUI_SERVER_ADDRESS from environment (required)
2. Validates the workflow name against allowlisted files in workflows/
3. Loads the workflow, injects the prompt and seed
4. Sends the workflow to ComfyUI via HTTP API
5. Polls for completion, downloads the result image
6. Saves to {skillDir}/output/ and prints a MEDIA: path