Build a curious rocket

A two-hour hands-on workshop on cpomdp, continuous active inference in Python, for the 6th Applied Active Inference Symposium. You build three rockets. The first is the 1960 controller, a Kalman filter with a goal, and the library reports that no move can teach it more than another. The second reads its position through a sensor that depends on where it is, and bends its path toward a beacon. In the third, three rockets fly past a rock none of them was told about.

Open it

The live session runs on Colab. There is nothing to install. A browser and a Google account are enough. Edits vanish when the tab closes unless you save a copy to Drive.

Open the notebook in Colab

Please write the lines yourself rather than asking a generative AI tool for them. The point of the session is the two lines you work out. The hints and the reference cells are there for when you are stuck. Using them is fine.

Run it locally

With uv:

git clone https://github.com/inferogenesis/cpomdp-workshop
cd cpomdp-workshop
uv sync --extra nb
uv run jupyter lab notebooks/build_a_curious_rocket.ipynb

Python 3.11 or newer. The workshop pins the cpomdp release it was measured on, and the first cell stops if a different one is installed.

Do not name a file in the folder you run from after a standard-library module, such as types.py, dis.py or random.py. Python imports yours instead. The error that follows points nowhere near the cause.

What is in the repo

Path	What it holds
src/cpomdp_workshop/	The package the notebook imports: the world, the two rockets, the flight loop, the checks, the figures
notebooks/	The notebook, generated and run by scripts/build_notebook.py. Never edited by hand
scripts/lesson.py	What the notebook says, cell by cell
delivery/hints_chat.txt	The hint lines pasted into chat. The notebook's hint and reference cells are built from it
assets/	Figures, regenerated from the package by scripts/render_assets.py
tests/test_measured_claims.py	One test per number the notebook or the deck shows
tests/test_api_contract.py	The cpomdp forms the workshop is written against

Working on it

Every command runs from the repo root.

uv sync --extra dev --extra nb
uv run --no-sync pytest -q -m "not slow"     # fast tests
uv run --no-sync pytest -q                   # everything, the notebook run included
uv run --no-sync pre-commit run --all-files  # the gate CI runs
uv run --no-sync python scripts/build_notebook.py
uv run --no-sync python scripts/render_assets.py

A change to the lesson, the hints or the package means rebuilding the notebook. A stale notebook fails a test.

Releasing

The notebook's first cell installs the exact version it was built from, so bump version in pyproject.toml, rebuild the notebook and merge. Then publish a GitHub release tagged v plus that version. .github/workflows/publish.yml runs the tests, installs the wheel into a clean environment and uploads to PyPI through Trusted Publishing.

Licence

MIT. See LICENSE.