nexus-crdt (Python)

Nexus — leaderless CRDT state synchronization for Python ≥ 3.10. Pure standard library: __slots__ everywhere, full typing (TypedDict, Protocol), pickle-able state, and asyncio helpers for I/O-bound sync.

pip install nexus-crdt

from nexus import NexusMap

m = NexusMap("server-1")
m.set("title", "Hello")
m.or_set("tags").add("crdt")
m.text("doc").insert(0, "hello")

m.merge(remote_frame)          # bytes — converges; simultaneous writes never raise
m.encode()                     # canonical TLV frame (byte-compatible with JS/PHP)
m.merkle_root()                # SHA-256 Merkle digest of the op history

asyncio

from nexus import NexusMap, async_merge, serve_state, fetch_state

await async_merge(m, ws.recv())                # merge without blocking the loop
server, port = await serve_state(m)            # tiny length-prefixed TCP relay
frame = await fetch_state("127.0.0.1", port, m.encode())

pickling

pickle.dumps(m) captures the whole state (canonical frame + actor) and is safe across processes/versions of the app.

Tests: pip install -e ".[test]" pytest-asyncio && pytest (pytest + hypothesis fuzzing + shared cross-language vectors).