The reference ONP/1 client and server I use for Raspberry Pi and backend projects.

python -m pip install \
  https://github.com/devkyato/OpenNet/releases/download/v0.2.3/opennet_protocol-0.2.3-py3-none-any.whl
opennet serve

import asyncio
from opennet import OpenNetClient

async def main():
    async with OpenNetClient("127.0.0.1") as client:
        await client.send("demo/message", {"hello": "OpenNet"}, retries=2)

asyncio.run(main())

The complete documentation, ESP32 Arduino library, examples, protocol specification, and security guidance are in the OpenNet repository.

The server also accepts an optional sync or async authorizer. It sees the validated frame and the peer's TLS certificate before the handler or ACK, which keeps topic rules in one explicit place. See Authorizing topics.

The wheel is distributed through GitHub Releases for v0.2.3; it is not yet published on the public PyPI index.