gridfab 0.4.1

Human-AI collaborative pixel art editor — artwork stored as plain text

GridFab

Pixel art editor where AI and humans edit the same sprite in real time — because the art is plain text.

GridFab is an open-source pixel art editor built around a radical idea: the artwork is stored as plain text files that both humans and LLMs can read and edit directly. It has two interfaces operating on the same files simultaneously:

1. A GUI editor (tkinter) for humans to paint, preview, and refine pixel art visually
2. A CLI tool for LLMs (via Claude Code, agentic coding tools, or scripts) to read the grid as text, reason about spatial layout, and make structured edits

The text-based format (grid.txt + palette.txt) is the canonical representation of the artwork. No other pixel art tool gives AI agents direct read/write access to a human-readable art format while a human simultaneously edits the same files in a GUI.

Why This Exists

I'm a hobby game dev making Veil of Ages in Godot. I wanted an LLM to help me create sprites, but no art tool speaks text. So I built one.

Quick Start

pip install gridfab
gridfab init --size 32x32
gridfab-gui .
# Start painting! Or ask your AI to edit grid.txt

The "Aha" Demo

The human-AI workflow looks like this:

1. Human: "Hey Claude, I need a red potion bottle sprite"
2. Claude reads grid.txt, writes palette entries, edits rows via CLI
3. Human hits Refresh in the GUI — sees the sprite instantly
4. Human: "Make the liquid darker and add a cork"
5. Claude edits grid.txt again
6. Final sprite in under 2 minutes

The grid.txt is readable by both parties:

. . . . . . . B B B B . . . . .
. . . . . . B R R R R B . . . .
. . . . . B R R R R R R B . . .
. . . . . B R R R R R R B . . .
. . . . . . B B B B B B . . . .

File Format

grid.txt

One row per line, space-separated values. Each value is:

• . — transparent
• A 1-2 character palette alias (e.g. R, SK, DG)
• An inline #RRGGBB hex color

palette.txt

One alias per line as ALIAS=#RRGGBB. Lines starting with # are comments.

# Character colors
R=#CC3333
SK=#FFCCAA
HR=#663311

gridfab.json

Optional config per sprite directory:

{
  "grid": { "width": 32, "height": 32 },
  "export": { "scales": [1, 4, 8, 16] }
}

CLI Reference

gridfab init [--size WxH] [dir]              # Create new sprite
gridfab render [dir]                          # Preview with checkerboard bg
gridfab export [dir]                          # Export PNGs at multiple scales
gridfab palette [dir]                         # Show palette colors
gridfab pixel <row> <col> <color>            # Set a single pixel
gridfab pixels <r,c,color> [...]             # Batch pixel placement
gridfab row <n> <v0 v1 ...> [--dir DIR]      # Replace a row
gridfab rows <start> <end> <values...>        # Replace row range
gridfab fill <row> <c0> <c1> <color>          # Fill horizontal span
gridfab rect <r0> <c0> <r1> <c1> <color>      # Fill rectangle
gridfab clear [dir]                           # Reset grid to transparent
gridfab icon [dir]                            # Export .ico and .icns icons
gridfab atlas <output> [sprites...] [opts]    # Pack sprites into spritesheet
gridfab import <image> [output] [opts]        # Import image to grid.txt format
gridfab tag <tileset.png> [opts]              # Interactive tileset tagger

GUI

gridfab-gui [directory]

• Left-click to paint, right-click to erase
• Palette sidebar with color swatches (add, edit, remove colors via color picker)
• Ctrl+Z / Ctrl+Y for undo/redo
• Ctrl+S to save
• Save, Render, Refresh, Clear, New, Open, and Import buttons

Features

• Configurable grid sizes (8x8, 16x16, 32x32, 64x64, or any WxH)
• Export at multiple scales (1x, 4x, 8x, 16x) with true transparency
• Preview rendering with checkerboard background
• Undo/redo in GUI (512-step history)
• 1-2 character palette aliases with case-insensitive collision detection
• Pixel-level editing commands (pixel, pixels, fill, rect, row, rows)
• Icon export (.ico and .icns) from square grids
• Atlas/spritesheet packing with multi-tile support, stable ordering, and JSON index
• Image import (PNG, BMP, GIF, TIFF, WebP, JPEG, and 20+ formats) to grid.txt
• Interactive tileset tagger with AI-assisted naming
• GUI palette editing (add, edit, remove colors with color picker)
• Auto-repair for malformed grid.txt files

Planned

• Animation support (multi-frame sprites, spritesheets, GIF export)
• AI workflow commands (describe, diff, flip, rotate, outline, patterns)
• Project management (multi-sprite projects, shared palettes)
• Game engine export (Godot SpriteFrames, Unity .meta)
• Layer support

For AI / LLM Users

GridFab is designed for AI-assisted pixel art workflows. The CLI is the API:

# An LLM can read the grid as plain text
cat grid.txt

# Make structured edits
gridfab pixel 5 13 DK
gridfab pixels 5,13,DK 5,14,WB 6,12,DK
gridfab rect 10 10 20 20 SK
gridfab fill 5 0 31 R

# Check palette
gridfab palette

Every editing operation is available via CLI. The text format means LLMs can reason about spatial layout, color distribution, and composition without vision capabilities.

Claude Code Skill

If you use Claude Code, install the GridFab skill to give Claude built-in knowledge of how to create and edit sprites:

# Copy the skill to your user-level skills directory
cp -r skills/gridfab-create ~/.claude/skills/gridfab-create

Once installed, Claude will automatically know how to use GridFab's CLI when you ask it to create or edit pixel art.

Installation

From PyPI

pip install gridfab

From Source

git clone https://gitlab.com/azrazalea/gridfab.git
cd gridfab
pip install -e .

Requirements

• Python 3.10+
• Pillow (image rendering)
• tkinter (GUI, included with Python)

Project Structure

gridfab/
  src/gridfab/          # Python package
    cli.py              # CLI entry point
    gui.py              # tkinter GUI
    core/               # Grid, Palette data structures
    render/             # Preview and export rendering
    commands/           # CLI command implementations
  tools/                # Standalone utility scripts
  examples/             # Example sprites
  tests/                # Test suite

Documentation

• INSTRUCTIONS.md — Full user manual: GUI guide, CLI reference, config options, suggested LLM prompt
• CHANGELOG.md — Version history
• CONTRIBUTING.md — How to contribute
• CODE_OF_CONDUCT.md — Contributor Covenant Code of Conduct
• GRIDFAB_PROJECT_SPEC.md — Full project roadmap and specification

Contributing

Contributions welcome! See CONTRIBUTING.md for guidelines and GRIDFAB_PROJECT_SPEC.md for the full roadmap.

License

This project is licensed under the GNU Affero General Public License v3.0 (AGPL-3.0).