engiNIR-OPCUA#

OPC UA for Python, from the lab bench to the plant floor: connect, serve and secure your devices in minutes.

engiNIR-OPCUA is a client and a server in one library, built on asyncio with a blocking API for scripts. It follows OPC UA 1.05; Supported features and limits lists what it covers.

uv add enginir-opcua

enginir-opcua init server srv --endpoint opc.tcp://127.0.0.1:4840/demo/
enginir-opcua init client cli
enginir-opcua pair srv/pki cli/pki
enginir-opcua user add srv/users.toml alice --role user

import asyncio

from enginir_opcua import Server


async def main() -> None:
    server = Server.quickstart("opc.tcp://127.0.0.1:4840/demo/", pki="srv/pki", users="srv/users.toml")
    await server.init()
    idx = await server.register_namespace("urn:example:demo")
    temperature = await server.nodes.objects.add_variable(idx, "Temperature", 21.5)
    async with server:
        while True:
            await asyncio.sleep(1)
            await temperature.write_value(await temperature.read_value() + 0.1)


asyncio.run(main())

import asyncio

from enginir_opcua import Client


async def main() -> None:
    client = Client.quickstart("opc.tcp://127.0.0.1:4840/demo/", pki="cli/pki", username="alice")
    async with client:
        idx = await client.get_namespace_index("urn:example:demo")
        temperature = await client.nodes.objects.get_child(f"{idx}:Temperature")
        print(await temperature.read_value())


asyncio.run(main())

The setup commands create both PKI directories and a user; nothing is trusted automatically, so enginir-opcua pair makes the two directories trust each other. The client reads the password of alice from ENGINIR_OPCUA_PASSWORD. Quick Setup explains every step.

Start here#

Quick setup

A secure server and client, the three profiles, configuration files, users and the trust commands.

Quick Setup
OPC UA basics

Nodes, namespaces, endpoints, security and sessions: the terms the rest of the documentation uses.

OPC UA Basics
Migrating from asyncua

What changes when you move an application from asyncua 2.x, and the first things to update.

Migrating from asyncua
Client

Connect, browse, read and write, call methods, subscribe, and survive a lost connection or a failed server.

Client Overview
Server

Endpoints, the security defaults, users and roles, methods and events, logging and observing.

Server Overview
Examples

Seventeen runnable programs, from a secure pair to alarms, history, file transfer and reverse connect.

Examples
Synchronous API

The same client and server for programs, scripts and notebooks that don’t use asyncio.

Synchronous Interface
PubSub

Publish and subscribe over UDP with UADP messages, without sessions. Experimental.

PubSub (experimental)
API reference

Every public module, class and function, generated from the source.

API Reference

Why engiNIR-OPCUA#

Complete. Subscriptions, methods, alarms and conditions, history, file transfer, certificate management and the companion models of whole industries, as a client and as a server.

Extended and hardened. Built on opcua-asyncio, brought up to OPC UA 1.05, extended with server-side alarms, file transfer, certificate management and reverse connect, and hardened against the attacks known for OPC UA servers.

Effortless. Encrypted from the first connection, set up with four commands, written in a few lines of async or plain blocking Python.

About the project#

engiNIR-OPCUA is a fork of opcua-asyncio 2.1.0, made on 2026-10-25. The original library was written by Olivier Roulet-Dubonnet and the opcua-asyncio contributors. The import package is enginir_opcua and the commands start with enginir-opcua, so it can be installed next to asyncua.