modelx Release Notes Roundup: v0.24.0 to v0.31.1

It has been a while since the last post here, but modelx development has continued steadily. This post summarizes the thirteen modelx releases published since then, from v0.24.0 (December 2023) to v0.31.1 (May 2026), based on the release notes for each version. For full details, follow the links to the release notes.

v0.31.1 (May 31, 2026)

• Added the info property for human-readable snapshots of modelx objects.
• Extended the CI test matrix with Python 3.8 and NetworkX 2.5.

Release notes

v0.31.0 (May 16, 2026)

• Serialized Python files now carry a pseudo-python header (introduced with a new serializer version, with backward compatibility restored for earlier formats).
• Added macro serialization support.
• Fixes include: an exporter crash on model-level (global) references, a crash in get_node_repr on unhashable keys when is_cached=False, a clearer error from read_model when the path is not a modelx model, and docstring serialization for special characters.
• Added Python 3.14 to the supported classifiers.

Release notes

v0.30.1 (January 24, 2026)

• Fixed typos in the Mortgage tutorial, contributed by a first-time contributor.

Release page

v0.30.0 (December 12, 2025)

• Introduced the Macro feature, which lets you define and store Python functions as part of a model, saved and loaded together with the model.
• New APIs to support it: the Macro class, the defmacro() decorator, the new_macro() method and the macros property.

Release notes

v0.29.2 (December 6, 2025)

• Introduced new_space_from_model(), which copies a model into another model as a space.
• Fixed an issue where creating child spaces in parameterized parent spaces with existing ItemSpaces did not properly clear the ItemSpaces and refresh the namespace.

Release notes

v0.29.1 (November 22, 2025)

• Introduced export_members() for exporting space members to a module’s global namespace.
• Added a tentative compare_cells() method for comparing identically named cells across spaces.
• Fixed an issue where system references were included in the refs property.

Release notes

v0.29.0 (November 2, 2025)

• Major refactoring to improve the core components of modelx.
• reload() and import_funcs() are deprecated and will be removed in future versions.
• Added support for Python 3.14.

Release notes

v0.28.1 (August 2, 2025)

• Error message tracebacks now include a “Caused by” section.
• Fixed an access-denied error during write operations on Windows.

Release notes

v0.28.0 (December 8, 2024)

• Reading models with read_model() is now significantly faster.
• Improved the error message when accessing non-existent names in a Space.
• Fixed an issue preventing values with unary minus operators from being stored as reference variables.

Release notes

v0.27.0 (August 25, 2024)

• Introduced uncached cells: the is_cached property, the @uncached decorator and is_cached parameters on defcells() and new_cells() allow formulas to skip caching, so they can accept unhashable arguments such as lists.
• Added @cached as an alias of defcells.
• Fixed two inheritance issues and extended formula trace messages to show up to 20 lines.

Release notes

v0.26.0 (July 15, 2024)

• Added underscore-prefixed properties (_parent, _name, _cells and others) as aliases on Model, Space and Cells objects, for compatibility with exported models.
• The del statement now works for removing UserSpace parameters and ItemSpace objects in exported models.

Release notes

v0.25.1 (June 13, 2024)

• A bug-fix release addressing GH-127.

Release page

v0.25.0 (February 18, 2024)

• Added the Model.path property, which lets formulas reference external files by paths relative to the model file’s location.
• Added support for Python 3.12.
• Backward-incompatible changes: the subscription syntax [] for calling cells was removed (use () instead), along with some Cells methods such as match().
• Fixed an export error on Python 3.12 and a PermissionError from read_model() on Windows.

Release notes

v0.24.0 (December 2, 2023)

• Child spaces are no longer inherited by default when a UserSpace inherits from another; this is a backward-incompatible change. Dynamic child spaces of parameterized spaces are not affected.
• Removed previously deprecated backup/restore functionality: restore_model(), open_model(), Model.backup() and Model.save().

Release notes