Subkernel Development

A subkernel adds a language runtime to Beaker. Beaker ships with Python, R, and Julia subkernels out of the box; this section covers building your own.

If you have not yet read the conceptual overview, see Key Concepts > Subkernels first.

Each subkernel is a Python package, discovered through Python entry points. The package layout is:

my_subkernel/
├── subkernel.py            # BeakerSubkernel (or CheckpointableBeakerSubkernel) subclass
└── procedures/
    ├── fetch_state.<ext>   # language-side helper script(s)
    └── reflectors/
        ├── default.<ext>   # per-type reflectors used to summarize variables
        └── ...

The CLI scaffolds this layout for you; see Creating a Subkernel to get started.