This is the scripting API for Aseprite. Since version 1.2.10 you are able to create scripts with Lua.

You can find some examples for this API or some tests.

Generally you will want to write a script to solve a problem or to do a little experiment, so you have six options to approach your idea:

1. Transform the active sprite: In this case app.sprite will give you access to the current sprite (it's nil if there is no active sprite, e.g. we are in the Home tab).
2. Create a new sprite : Here the Sprite() function creates a new sprite and sets it as the active one. From there you can modify the Sprite object as you want.
3. Open one or several existing files: You can use app.open to load a sprite from the disk and then modify it.
4. Save the modified sprite: After you have done some modifications to a sprite, you might want to save the result directly to the disk, Sprite:saveCopyAs() function is a good option to export the modified sprite.
5. Show a dialog to the user: The Dialog object gives you the possibility to show controls to the user to enter values.
6. Add new options to any menu: In this case you'll need to create a plugin with a script.

API changes between versions.

Global namespace

• app
• app.clipboard
• app.command
• app.fs
• app.os
• app.pixelColor
• app.theme
• json

Constants

• Align
• AniDir
• BlendMode
• BrushPattern
• BrushType
• ColorMode
• FilterChannels
• FlipType
• Ink
• MouseButton
• MouseCursor
• RangeType
• SelectionMode
• SpriteSheetDataFormat
• SpriteSheetType
• TilemapMode
• TilesetMode
• WebSocketMessageType

Classes/objects

• Brush
• Cel
• Color
• ColorSpace
• Dialog
• Editor
• Events
• Frame
• GraphicsContext
• Grid
• Image
• ImageSpec
• KeyEvent
• Layer
• MouseEvent
• Palette
• Plugin
• Point
• Range
• Rectangle
• Selection
• Site
• Size
• Slice
• Sprite
• Tag
• Tile
• Tileset
• Timer
• Tool
• TouchEvent
• Version
• Uuid
• WebSocket
• Window

Lua libraries

• Base library and Basic Functions in Lua manual
• Coroutine Manipulation
• String Manipulation
• UTF-8 Support
• Table Manipulation
• Mathematical Functions
• Operating System Facilities
  • Some functions like os.exit, os.tmpname are not available yet
  • Other functions like os.execute and io.open will ask for permissions to the user
• The Debug Library