Durable MemoryStore over Redis. Each document is a hash; each namespace keeps a sorted set of its paths (score 0, so lexical order) for listing and prefixes. Every write is one Lua script, so compare-and-set, rename and delete_tree are atomic. All of a namespace's keys share the {namespace} hash tag, so they live in one Redis Cluster slot; the scripts derive document keys from the declared index key's prefix. A namespace's content bytes live in a counter key beside its index (the document count is the index's size), kept by the same scripts, so put/6's limits are checked in the write's script.

The handle is {conn, prefix}; the host owns the Redix connection.