| name | scratch-coder |
| description | Create Scratch 3.0 projects using Python and ScratchGen. Use when the user wants to generate a .sb3 file with sprites, scripts, and assets. |
| license | MIT |
| compatibility | claude-code opencode github-copilot devin pi cursor |
Scratch Coder
Create Scratch 3.0 projects with Python and ScratchGen.
Setup
pip install "ScratchGen~=1.1"
Quick start
from ScratchGen import *
project = Project()
sprite = project.createSprite('Cat')
sprite.createScript(
WhenFlagClicked(),
Show(),
Say('Hello!')
)
project.save('hello.sb3')
Common pitfalls
- Sprites are hidden by default. Call
Show() in WhenFlagClicked().
- Sprites have no default costume. Add costumes via
addCostume() or inject them after saving.
Broadcast() / WhenBroadcastReceived() use null IDs in ScratchGen. Use ChangeVariable on global stage variables for cross-sprite state instead.GetAttribute requires ScratchGen constants, not strings: GetAttribute(Y_POSITION, ball).Stop(ALL) clears speech bubbles before rendering. Use a game_over state variable plus a dedicated message sprite.- Stage fence clamps sprites at
y = -180 to 180. Keep detection thresholds inside the bounds.
Stage coordinates
- x: -240 to 240
- y: -180 to 180
Physics tips
- Keep
MoveSteps(N) <= half the target sprite's width to avoid tunneling.
- For axis-aligned games, store direction as
dx/dy stage variables and move with ChangeX(Multiply(dx, speed)).
Save pipeline
project.save() -> add_costumes() -> add_monitors()
Testing
python -c "import zipfile; print(zipfile.ZipFile('project.sb3').namelist())"
Open the file in TurboWarp to verify.
Reference
references/block-reference.md — complete block reference
