mxm-foundry 0.1.1

Policy-driven validation and standardisation tool for Money Ex Machina Python packages.

mxm-foundry defines what constitutes a valid MXM package and provides a single interface (mxm-foundry check) to enforce that contract.

Purpose

MXM packages are designed to be:

• structurally consistent
• fully typed
• reproducibly configured
• CI-ready by construction
• easy to reason about across repositories

mxm-foundry enforces this through a set of checks and policies covering:

• filesystem structure
• pyproject.toml semantics
• typing configuration (Pyright)
• formatting configuration (Black, Ruff, Isort)
• Makefile orchestration (lint, type, test, check)
• testing conventions (pytest)
• documentation structure (README.md, CHANGELOG.md)
• license compliance

A package that passes all checks satisfies the MXM publish contract.

Installation

pip install mxm-foundry

Usage

Run the validation tool against a project:

mxm-foundry check <project-root>

Example:

mxm-foundry check .

Output is grouped by policy and reports:

• individual check results
• policy-level pass/fail status
• summary counts
• non-zero exit code on failure (CI-compatible)

Policy Model

mxm-foundry organises validation into policies:

• License policy — LICENSE presence and canonical content
• Typing policy — Pyright configuration, absence of [tool.pyright], typing markers
• Formatting policy — canonical Black, Ruff, Isort configuration and Makefile integration
• Pyproject policy — structural correctness of pyproject.toml
• Testing policy — pytest usage and Makefile integration
• Check-gate policy — enforcement of make check as integration point
• Documentation policy — README structure and CHANGELOG presence/format
• Misc policy — remaining structural checks

Each policy aggregates multiple checks and fails atomically if any check fails.

Canonical Configuration

MXM packages are standardised against canonical definitions shipped with mxm-foundry:

• canonical/pyproject.toml
• canonical/pyrightconfig.json
• canonical/Makefile

Checks compare project configuration exactly against these canonical sources.

This ensures:

• zero configuration drift across packages
• predictable tooling behaviour
• uniform developer experience

Makefile Contract

The Makefile is a first-class interface in MXM packages.

Required targets:

• fmt — formatting (ruff --fix, black, isort)
• lint — static checks (ruff, black --check, isort --check)
• type — type checking (pyright)
• test — pytest execution
• check — aggregate of lint, type, test
• ci — alias for check

make check is the canonical publish gate.

Design Principles

• Single validation interface
  One command (mxm-foundry check) defines package validity.

• Policy-driven architecture
  Checks are grouped into semantic domains rather than treated independently.

• Canonical configuration
  Tooling configuration is not inferred or approximated; it is enforced.

• Deterministic results
  Checks run in a fixed order with stable output.

• Strict typing
  Fully Pyright-clean and PEP 561 compliant.

• Minimal implicit behaviour
  All structure and configuration is explicit and inspectable.

Development

poetry install

make check

poetry run mxm-foundry --help

License

MIT License. See LICENSE.