ipynb is a Haskell library for representing Jupyter notebooks and converting them to and from the JSON .ipynb format. The format is documented here: https://nbformat.readthedocs.io/en/latest/.

Both version 4 and version 3 are supported, though the data structure used is the same. A phantom type is used to provide different JSON serializations for the two versions. When working with version 4, use Notebook NbV4; when working with version 3, use Notebook NbV3.

The test suite verifies that write . read and read . write are identities, up to semantically insignificant differences in the JSON output.

The JuPyTer-notebook library has a similar job description, but there are some important differences:

• JuPyTer-notebook parses code cell output as JSON; ipynb has a custom representation of Output.

• JuPyTer-notebook allows representing some illegal cells (e.g., with cell_type markdown but also with execution_count and outputs). ipynb goes further in making illegal notebooks unrepresentable.

• ipynb supports both v3 and v4 of nbformat, both in reading and writing; JuPyTer-notebook supports only v4 (and does not support the more recent v4 feature, attachments).

• JuPyTer-notebook parses some notebook metadata into custom structures (using data type disjunction (:|:) to provide a fallback of text or a JSON value when parsing fails). ipynb just leaves all metadata as JSON Values.

• JuPyTer-notebook depends on json-autotype, and thus has a much heavier transitive dependency graph than ipynb.