aseprite-mcp

Aseprite MCP Tools

A Python MCP server that gives AI assistants full control over Aseprite for creating pixel art and animated sprites.

104 tools across 17 categories — canvas, drawing, layers, animation, palettes, effects, slices, tilemaps, exports, visual-feedback/analysis tools, and a raw Lua escape hatch. The tool set is designed so an LLM has everything it needs to produce good pixel art, not just primitives: shading ramps with hue shifting, ordered dithering, outlines, retro palette presets with quantization, onion-skin renders, and frame diffing for animation work.

Example: a swordsman, drawn and animated by Claude

<table> <tr> <td align="center"><img src="examples/swordsman/swordsman.png" width="256" alt="Pixel-art swordsman drawn by Claude Fable 5"></td> <td align="center"><img src="examples/swordsman/swordsman_slash.gif" width="256" alt="4-frame sword slash animation by Claude Fable 5"></td> </tr> <tr> <td align="center">_{<b>Task 1</b> — <em>"Draw me a pixel art of a swordsman."</em><br>32×32 still, exported at 10×.}</td> <td align="center">_{<b>Task 2</b> — <em>"…a sword slash attack sequence, from windup to follow-through."</em><br>4-frame animation, exported with <code>export_tag</code>.}</td> </tr> <tr> <td align="center" colspan="2"><img src="examples/swordsman/swordsman_slash_sheet.png" width="520" alt="Slash sequence spritesheet: windup, extension, swing, follow-through"></td> </tr> <tr> <td align="center" colspan="2">_{The same slash as a spritesheet (<code>export_spritesheet</code>): windup → extension → swing → follow-through.}</td> </tr> </table>

Both were created end-to-end by Claude Fable 5 through this server's MCP tools — drawing, checking its own work with scaled export_frame previews and render_onion_skin, then exporting. The tasks recreate the benchmark from Draw Me a Swordsman by Lj Miranda, whose findings inspired this server's expanded toolset.

Tool Categories

| Category | Tools | Description | |----------|------:|-------------| | Canvas | 6 | Create sprites, manage layers/frames, set the active state | | Drawing | 14 | Pixels, lines, rectangles, circles, ellipses, polygons, paths, fills, gradients | | Text | 3 | Draw and measure text with bitmap sprite-sheet or TrueType fonts | | Layers | 7 | Delete, rename, duplicate, reorder, blend modes, merge, flatten | | Selection & Regions | 4 | Move, copy, and erase rectangular regions or colors | | Effects | 5 | Outlines, color replacement, HSL adjustment, ordered dithering | | Animation | 24 | Frames, cels, tags, tweening with easing, propagation | | Palette | 8 | Get/set palettes, retro presets, color ramps, quantization, color modes | | Transform | 4 | Flip, rotate, resize, crop | | Slices | 5 | Named regions, 9-patch centers, pivot points | | Tilemap | 5 | Tilemap layers, tileset editing, tile placement | | Export & Import | 7 | PNG, GIF, sprite sheets, per-layer/per-tag export, image import | | Inspection | 3 | Read pixels and sprite metadata | | Analysis & Visual Feedback | 3 | Onion-skin renders, frame diffing, color statistics | | Quality | 4 | Validate and sanitize animation consistency | | Scene | 1 | Copy layers between sprite files | | Preview & Guide | 3 | Local HTTP preview server, workflow guide | | Scripting | 1 | Raw Lua escape hatch for anything not covered above |

Canvas

| Tool | Description | |------|-------------| | create_canvas | Create a new sprite with the given dimensions | | add_layer | Add a new layer, optionally inside a named group | | add_group | Add a new (optionally nested) group layer | | add_frame | Append a new frame | | set_frame | Set the active frame | | set_frame_duration | Set one frame's duration in ms | | set_layer | Set the active layer (optionally creating it) |

Drawing

All _at variants target a specific layer/frame and can create the cel on demand. Coordinates are sprite-global.

| Tool | Description | |------|-------------| | draw_pixels | Plot individual pixels with per-pixel colors | | draw_pixels_at | Plot pixels on a specific layer/frame | | draw_line / draw_line_at | Lines with thickness | | draw_rectangle / draw_rectangle_at | Outlined or filled rectangles | | draw_circle / draw_circle_at | Outlined or filled circles | | draw_ellipse_at | Outlined or filled ellipses with separate x/y radii | | draw_polygon | Outlined or filled polygons from a point list | | draw_path | Polyline through a point list with thickness | | fill_area / fill_area_at | Paint-bucket flood fill | | apply_gradient_rect | Smooth linear gradient fill in a rectangle |

Text

Aseprite's Lua API has no text drawing, so glyphs are rasterised on the server and composited into the sprite. Two font backends are supported: bitmap sprite-sheet fonts (the right choice for pixel art — glyphs are already pixels and size scales them by whole numbers) and TrueType .ttf/.otf files, rendered without antialiasing unless you ask for it.

Fonts are discovered in ~/.aseprite-mcp/fonts: a bitmap font is a directory containing font.json plus its sheet PNGs; a TrueType font is just the font file. Installed system fonts are listed too. font also accepts a direct path.

| Tool | Description | |------|-------------| | list_text_fonts | List the bitmap and TrueType fonts available to draw_text | | measure_text | Width, height, advance and baseline extents — size a panel or centre a label without redrawing to find out | | draw_text | Draw text with anchors, faux bold, outline, drop shadow and letter spacing |

Call measure_text first when the layout depends on the text: it returns the same metrics draw_text will use, so a label can be centred or a plate sized in one pass.

measure_text(text="MODERATOR", font="minecraft", size=2, bold=1)
  -> width=115 height=15 advance_width=117 above_baseline=14 below_baseline=1 left_bearing=0

draw_text(filename="badge.aseprite", text="MODERATOR", x=64, y=17,
          font="minecraft", size=2, anchor="baseline", bold=1,
          color="#FFFFFF", shadow_color="#14237A")

Anchors are topleft/top/topright, left/center/right, bottomleft/bottom/bottomright, plus baselineleft/baseline/baselineright for pinning several labels to one baseline. Outline and shadow grow the stamp but never move the glyphs.

font.json

{
  "name": "my-font",
  "letter_gap": 1,
  "space_width": 3,
  "sheets": [{
    "file": "sheet.png",
    "cell_w": 8, "cell_h": 8,
    "ascent": 7,
    "chars": [" !\"#$%&'()*+,-./", "0123456789:;<=>?"]
  }],
  "overrides": {
    "86": {"ascent": 7, "rows": ["#...#", "#...#", ".#.#.", "..#.."]}
  }
}

Each sheet carries its own ascent, so sheets with different cell sizes still share a baseline — that is how a compact ASCII sheet and a taller accented sheet combine into one run. origin shifts the cell grid when the sheet has a margin, ink_rule: "dark" reads sheets that use an opaque white background to delimit variable-width glyph boxes, and advance: "box" takes the advance from the box rather than the ink. overrides replaces individual glyphs with hand-drawn rows, which is useful when a sheet ships a glyph that is off-centre or too tall to sit on the line.

Layers

| Tool | Description | |------|-------------| | delete_layer | Delete a layer by name | | rename_layer | Rename a layer | | duplicate_layer | Duplicate a layer with all cels, opacity, and blend mode, optionally into a group | | reorder_layer | Move a layer to a position in the stack | | set_layer_blend_mode | Set blend mode (multiply, screen, overlay, ... 19 modes) | | merge_layer_down | Merge a layer into the one below it | | flatten_sprite | Flatten all layers into one |

Selection & Regions

| Tool | Description | |------|-------------| | move_region | Cut a rectangle of pixels and paste it elsewhere | | copy_region | Copy a rectangle to another position, layer, or frame | | erase_region | Make a rectangle transparent | | erase_color | Magic-eraser: make all pixels of a color transparent (with tolerance) |

Effects

The pixel-art toolbox: clean outlines, palette-respecting blends, and shading variants.

| Tool | Description | |------|-------------| | outline_cel | Add a 1px outline around all opaque pixels | | replace_color | Replace one color with another (with tolerance), preserving alpha | | adjust_hsl | Shift hue/saturation/lightness of a cel — palette swaps, night scenes, shadows | | apply_dither_gradient | Two-color gradient using Bayer 4×4 ordered dithering | | apply_dither_pattern | Uniform dithered mix of two colors at a given density |

Animation

| Tool | Description | |------|-------------| | add_frames | Append N frames with optional duration | | delete_frame | Delete a frame | | set_frame_duration_all | Set every frame's duration | | duplicate_frame_range | Duplicate a frame range N times | | copy_frame / propagate_frame_to_range | Copy all cels of a frame to other frames | | create_cel / clear_cel / copy_cel | Cel lifecycle on a layer/frame | | propagate_cels | Copy selected layers' cels across a frame range | | set_cel_position | Place a cel at x,y | | set_cel_opacity | Set a single cel's opacity | | offset_cel_positions | Shift cels by a delta across frames | | tween_cel_positions | Linear position tween across frames | | tween_cel_positions_eased | Position tween with easing (ease_in/out, smoothstep) | | tween_cel_opacity_eased | Opacity tween with easing | | tween_cel_scale_eased | Scale tween with easing and anchor | | oscillate_cel_positions | Sine-wave motion (bobbing, breathing, hovering) | | set_tag / delete_tag | Animation tags with direction (forward/reverse/pingpong) | | set_layer_visibility / set_layer_opacity | Layer-level visibility and opacity | | set_onion_skin | Configure onion-skin UI prefs (see render_onion_skin for batch use) | | get_sprite_info | Sprite metadata: size, layers, frames, durations, tags |

Palette

| Tool | Description | |------|-------------| | get_palette | Read the palette as hex colors | | set_palette | Set the palette from a list of hex colors | | list_palette_presets | List built-in retro palettes | | apply_palette_preset | Apply a preset: gameboy, pico8, c64, cga, dawnbringer16, dawnbringer32, grayscale_4, monochrome | | generate_color_ramp | Build a dark→light shading ramp with hue shifting from a base color | | quantize_to_palette | Snap every pixel to the nearest palette color | | remap_colors_in_cel_range | Remap specific colors across a frame range | | set_color_mode | Convert between RGB, grayscale, and indexed |

Transform

| Tool | Description | |------|-------------| | flip_layer | Flip a cel horizontally or vertically | | rotate_layer | Rotate a cel 90/180/270° | | resize_canvas | Scale the sprite to new dimensions | | crop_canvas | Crop to a rectangle |

Slices

| Tool | Description | |------|-------------| | create_slice | Create a named rectangular region | | set_slice_center | Set the 9-patch stretchable center | | set_slice_pivot | Set the pivot point | | list_slices | List all slices with bounds, centers, pivots as JSON | | delete_slice | Delete a slice |

Tilemap

| Tool | Description | |------|-------------| | create_tilemap_layer | Add a tilemap layer with its own tileset and tile grid | | draw_on_tile | Paint pixels into a tileset tile (auto-appends new tiles) | | set_tiles | Place tiles on the map by grid position | | get_tile_at | Read which tile occupies a grid cell | | get_tilemap_info | Tile size, tile count, and map dimensions as JSON |

Export & Import

| Tool | Description | |------|-------------| | export_sprite | Export to PNG, GIF, JPG, ... | | export_frame | Export one frame as PNG with integer upscaling — the core visual-feedback loop: draw, export at 8×, look, iterate | | export_spritesheet | Sprite sheet (horizontal/vertical/rows/columns/packed) with optional JSON metadata and per-tag filtering | | export_layers | One PNG per layer | | export_tag | Export an animation tag as GIF or PNG sequence | | import_image_as_layer | Import a PNG into a layer (references, premade parts) | | copy_sprite | Duplicate the .aseprite file |

Inspection

| Tool | Description | |------|-------------| | get_pixel_color | Read one pixel's RGBA | | get_pixels_rect | Read a rectangle of pixels as JSON | | get_sprite_info | Sprite metadata (also listed under Animation) |

Analysis & Visual Feedback

Batch-mode equivalents of what a human artist gets from the Aseprite UI.

| Tool | Description | |------|-------------| | render_onion_skin | Render a frame over translucent ghosts of neighboring frames — check motion continuity without opening Aseprite | | compare_frames | Diff two frames: changed pixel count, percentage, bounding box | | get_color_stats | Color histogram of a frame — catches palette drift and near-duplicate colors |

Quality

| Tool | Description | |------|-------------| | ensure_layers_present | Create missing cels for layers across a frame range | | validate_scene | Report missing layers/cels as JSON | | audit_animation | Audit frames for overlaps and out-of-range layer activity | | animation_sanitize | Normalize layer order, coverage, and overlaps |

Scene

| Tool | Description | |------|-------------| | copy_layers_between_sprites | Copy layers by name from one .aseprite file to another |

Preview & Guide

| Tool | Description | |------|-------------| | start_preview_server / stop_preview_server | Serve exported files over local HTTP | | animation_workflow_guide | Returns a step-by-step workflow guide for the LLM |

Scripting

| Tool | Description | |------|-------------| | run_lua_script | Execute arbitrary Aseprite Lua (API docs) in batch mode. The escape hatch when no dedicated tool fits: one script can batch many operations into a single Aseprite launch. Remember to spr:saveAs(spr.filename) and print() your results. ⚠️ Runs unrestricted code on the host — only pass scripts you trust. |

Recommended Workflow for LLMs

1. Plan the palette first: generate_color_ramp for each material (skin, armor, blade), or apply_palette_preset for a retro look.
2. Build in layers: background / body / equipment / effects, so parts can be animated and edited independently.
3. Draw coarse to fine: silhouette with draw_rectangle_at / draw_ellipse_at / fill_area_at, then refine with draw_pixels_at.
4. Look at your work: export_frame at 8×, inspect, fix, repeat. Use get_color_stats to keep the palette tight.
5. Shade with intent: adjust_hsl for shadow layers, apply_dither_gradient for blends, outline_cel for readability.
6. Animate with the cel tools: propagate_cels, then tween_cel_positions_eased / oscillate_cel_positions; verify with render_onion_skin and compare_frames; export with export_tag.

Docker Usage

Quick Start

Build and run the Docker image: ``bash docker build -t aseprite-mcp:latest . docker run -it --rm aseprite-mcp:latest ``

Or use the provided build scripts:

• Linux/macOS: chmod +x build-docker.sh && ./build-docker.sh
• Windows: .\build-docker.ps1

Using Docker Compose

# Production
docker-compose up aseprite-mcp

# Development mode
docker-compose --profile dev up aseprite-mcp-dev

See DOCKER.md for detailed Docker setup instructions.

Optional: Install Aseprite via Steam

To have the container install Aseprite via SteamCMD at startup, provide Steam credentials:

# Create a .env with STEAM_USERNAME/STEAM_PASSWORD (and optional STEAM_GUARD_CODE)
# Then
docker run --rm -i --env-file .env aseprite-mcp:latest

If installed, the binary will be at /opt/steamapps/common/Aseprite/aseprite and ASEPRITE_PATH will be picked up automatically.

Local Installation

Prerequisites

• Python 3.13+
• uv package manager
• Aseprite (set ASEPRITE_PATH in .env if it is not on your PATH)

Installation:

{
  "mcpServers": {
      "aseprite": {
          "command": "/opt/homebrew/bin/uv",
          "args": [
              "--directory",
              "/path/to/repo",
              "run",
              "-m",
              "aseprite_mcp"
          ]
      }
  }
}