git clone https://github.com/<your-username>/BESSER.git
cd BESSER
python -m venv venv
# Windows: venv\Scripts\activate
# macOS/Linux: source venv/bin/activate
pip install -r requirements.txt
pip install -r docs/requirements.txt  # for building docs
pip install -e .                       # editable install

Verify: python tests/BUML/metamodel/structural/library/library.py

Python 3.11+ is required (enforced by python_requires = >=3.11 in setup.cfg; CI tests 3.11 and 3.12).

Reference layout

This skill keeps SKILL.md short. Reach into references/ for the procedure you need:

Task	Read
Add a new generator (the most common contribution) — 6 steps + scaffold	`references/adding-a-generator.md`
Add a new metamodel / sub-DSL, plus JSON↔BUML converters	`references/adding-a-metamodel.md`
Write pytest tests (fixtures, `tmp_path`, what to assert)	`references/testing.md`
Build the Sphinx docs and cross-reference them	`references/docs-and-build.md`
Code style, commit/PR conventions, cross-repo, CI/release	`references/contributing-workflow.md`

Related skills for the using side (not contributing):

Running or customizing an existing generator → the besser-generators skill.
Diagnosing install/import/generation errors → the besser-troubleshooting skill.
The user-facing shape of a model type (doc templates) → the besser-user skill's references/.

Common Contribution Pitfalls

Don't duplicate logic — shared helpers go in besser/utilities/, not in individual generators.
Maintain determinism — generators must produce identical output for identical input.
Keep converters symmetric — if JSON → BUML supports a feature, BUML → JSON must too.
Update docs — any backend change likely needs docs/source/ updates.
Don't touch the frontend submodule unless explicitly required. UI changes go to the upstream WME repo.
Clean up resources — always use try/finally for temp directories and file handles.
Test round-trips — especially for converters (JSON → BUML → JSON should be identity).

besser-dev

Contributing to BESSER

Development Setup