node-opcua

The most complete OPC UA stack for Node.js and the browser, written in TypeScript.

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Why node-opcua?

• Full OPC UA stack — Client, Server, Discovery, and Aggregation in a single toolkit
• Security first — Supports all OPC UA security policies, encrypted communication, and certificate management out of the box
• Cross-platform — Runs on Windows, Linux, macOS, and in the browser
• Modular architecture — Use only the packages you need, from a lightweight client to a full-featured server
• Battle-tested — Trusted in production by industrial companies worldwide
• Well documented — Comprehensive book, API reference, tutorials, and guided examples

Quick Start

Install node-opcua as an npm package

$ mkdir myproject
$ cd myproject
$ npm init
$ npm install node-opcua

Try the sample server & client

$ npm install node-opcua-samples
$ ./node_modules/.bin/simple_server

$ ./node_modules/.bin/simple_client -e "opc.tcp://opcuademo.sterfive.com:26543"

Node.js Requirement

• Node.js 20 or above is required.

Documentation

NodeOPCUA by Example — The best starting point. Dozens of practical, ready-to-use, and fully documented examples.

Tutorials

• Create a Server
• Create a Client in TypeScript
• Role-Based Security & User Management (OPC 10000-18)
• More advanced examples and training material are available for NodeOPCUA Subscription members

API Reference

• API Documentation

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🏢 Professional Support

Need help with your OPC UA project? Sterfive offers professional support and consulting for node-opcua.

	Community (GitHub)	Professional (Sterfive)
GitHub Issues	✅	✅
CVE security advisories	After disclosure	Early access — patch before public disclosure
Private support channel	—	✅
Extended documentation	—	✅
Guaranteed response time	—	✅
Consulting & training	—	✅
Certifiable builds	—	✅

📧 Contact: contact@sterfive.com · 🌐 sterfive.com

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Ecosystem

AI-Powered Modeling with MCP

node-opcua-modeler-mcp-server — An MCP server that gives AI agents access to the OPC UA companion specification type system. Discover types, resolve namespace dependencies, and look up engineering units — all from your AI coding assistant.

npx node-opcua-modeler-mcp-server

OPC UA Modeler

OPC UA Modeler — Create, validate, and generate OPC UA information models using a YAML-first workflow with full companion spec support.

Supported Features

node-opcua implements a comprehensive set of OPC UA services, transport protocols, security policies, and server/client profiles.

👉 View the full supported features matrix

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Roadmap

• Improved documentation and more tutorials
• Compliance testing and certification (CTT)
• Support for redundancy
• Session-less transactions
• JTokens and OAuth

Want to influence the roadmap? Contact Sterfive.

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:heart: Sponsors

node-opcua is funded entirely by its users. If you use node-opcua in your project, please consider supporting its continued development:

• 🌟 Become a sponsor on GitHub

Your sponsorship ensures long-term maintenance, new features, bug fixes, and representation of the node-opcua community at the OPC Foundation.

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Contributors

This project exists thanks to all the people who contribute.

Contributing

We welcome contributions! Here's how to get started with the source:

$ git clone git://github.com/node-opcua/node-opcua.git
$ cd node-opcua
$ npm install -g pnpm
$ pnpm install
$ pnpm recursive install
$ pnpm build

Running the demo server from source

$ node packages/node-opcua-samples/bin/simple_server

Running the demo client from source

$ node packages/node-opcua-samples/bin/simple_client.js -e "opc.tcp://opcuademo.sterfive.com:26543"

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License

node-opcua is MIT licensed.

• You can freely use it in open-source and commercial applications.
• You must include the copyright notice in all copies or substantial portions of the software.
• node-opcua comes without any warranty of any kind.

You are strongly encouraged to join the NodeOPCUA Membership for additional benefits and support.

Copyright

Copyright © 2014-2026 Sterfive SAS — 833264583 RCS ORLEANS — France (sterfive.com)