---
title: Metaclasses
description: API reference for ArchiPy helper metaclasses.
---

# Metaclasses

The `helpers/metaclasses` subpackage provides Python metaclass implementations for structural patterns such as the
singleton, giving classes framework-level behavioral guarantees.

## Singleton

A thread-safe metaclass implementation of the singleton pattern that ensures a class has exactly one instance.

::: archipy.helpers.metaclasses.singleton
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