McCache/McCache-for-Python ? reverse-engineered prompt

Build me a Python library that gives me a normal dictionary style cache, but keeps multiple app instances in sync automatically.

I want it to work as an in memory local cache first, then use UDP multicast so other nodes in the same cluster see inserts, updates, and deletes without me having to call a separate cache service like Redis. Make it feel like using a regular dict, with simple get, set, delete, membership checks, plus a way to inspect metadata, checksums, and basic metrics for a cache namespace.

It should support a cache size limit, TTL based eviction, a configurable sync mode, and optional encrypted network traffic with a secret key. Please include a small demo, tests, and clear docs for running it locally, including in Docker if that helps. Keep it lightweight, fast, and easy to drop into an existing Python project. If you need to, look up current docs online for any networking or crypto details.