Mastodon.py is a mature Python client library for the Mastodon social network API. It provides a comprehensive, type-safe interface to all Mastodon endpoints (statuses, accounts, timelines, notifications, admin, streaming, etc.) with built-in pagination, rate limiting, OAuth authentication, and version compatibility detection. The library is split across multiple modules that compose a single `Mastodon` class via inheritance, offering both synchronous and streaming access. It is extensively tested against a local Mastodon instance using VCR-recorded cassettes and supports optional features like WebPush notifications, blurhash decoding, and grapheme-based status length calculation. The codebase is well-maintained with modern Python packaging (pyproject.toml), type annotations, and support for Python 3.6 through 3.14.