# opcua (FreeOpcUa Python OPC UA library)

OPC UA library for python >= 3.10

Repository: https://github.com/FreeOpcUa/opcua-asyncio
Canonical: https://ross.abutalabs.com/products/opcua-freeopcua-python-opc-ua-library
Language: Python
License: LGPL-3.0
License Family: copyleft
Topics: python3, opc-ua, asyncio, iec62541, protocol, opcua
Last push: 2026-08-24T12:47:48+00:00
Link (homepage): http://freeopcua.github.io/

## Health v2 (maintenance only)
Score: 92/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 99, release rhythm 78, longevity 100
- inputs: {"age_days": 2953, "days_push": 9, "days_rel": 65, "gap_med": 61.0, "n_releases_24m": 7}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1468, forks 452 (observed 2026-08-28T04:04:48.912337+00:00)

## What it is
A pure Python implementation of the OPC-UA (IEC 62541) protocol providing both client and server libraries with high-level and low-level APIs. This original synchronous library is now deprecated in favor of its successor, opcua-asyncio (asyncua), which offers an asyncio-based implementation with a sync wrapper.

## Use cases
- connect to an OPC-UA server from Python
- build a Python OPC-UA server for industrial equipment
- read and write PLC tags over OPC-UA
- integrate SCADA or industrial automation data with Python
- test OPC-UA endpoints with a lightweight client
- browse OPC-UA address space programmatically

## When to choose
- maintaining legacy Python 2 or synchronous codebases that already use the opcua package
- you need a pure Python OPC-UA stack with no native dependencies
- quick prototyping of OPC-UA clients or servers

## When to avoid
- starting a new project - use opcua-asyncio (asyncua) instead
- you need actively developed features or architectural improvements
- you need guaranteed long-term bug fixes or security patches

## Facets
- artifact type: library
- maturity: maintenance
- function: sdk, networking, concurrency
- domain: iot, developer-tools, apis
- platform: python, cross-platform, windows
- tags: opc-ua, iec-62541, industrial-protocols, client-server, deprecated-in-favor-of-asyncua, pure-python, industrial-automation, linux, macos

## Member repositories
- FreeOpcUa/opcua-asyncio (main) score 92
- FreeOpcUa/python-opcua (mirror) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:04:48.912337+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T04:33:38.807798+00:00, confidence not recorded.
  - readme: https://github.com/FreeOpcUa/opcua-asyncio (fetched 2026-08-28T04:04:48.912337+00:00, sha cf40df3853a3)
  - homepage: http://freeopcua.github.io/ (fetched 2026-08-29T11:39:36.851537+00:00, sha 269a019bd3fb)
- Data as of 2026-08-30T08:39:29.467469+00:00.