# node-opcua-constants > pure nodejs OPCUA SDK - module constants Latest version **2.185.0** (published 2026-09-19) · MIT license · 0 weekly downloads ## Install ```sh npm install node-opcua-constants pnpm add node-opcua-constants yarn add node-opcua-constants bun add node-opcua-constants ``` ## Health **Score 70/100 (B)** — status: active. Positive: has types; esm support; no vulnerabilities; has provenance; recently updated; high maintenance score. Warnings: low downloads. ## Facts | | | |---|---| | Version | 2.185.0 | | Published | 2026-09-19 | | First published | 2017-09-10 | | Weekly downloads | 0 | | License | MIT | | TypeScript types | bundled | | Module format | ESM + CommonJS | | Node | >=22.13.0 | | Dependencies | 0 | | Unpacked size | 770.3 KB | | Known vulnerabilities | 0 | | Install scripts | no | | Provenance | attested (GitHub Actions) | | GitHub stars | 1664 | | Author | Etienne Rossignon | | Maintainers | erossignon | | Keywords | OPCUA, opcua, m2m, iot, opc ua, internet of things | ## Links - npm: https://www.npmjs.com/package/node-opcua-constants - Repository: https://github.com/node-opcua/node-opcua - Homepage: http://node-opcua.github.io/ - Issues: https://github.com/node-opcua/node-opcua/issues - npm.io page: https://npm.io/package/node-opcua-constants ## Recent versions - 2.185.0 (latest) — 2026-09-19 - 2.184.0 — 2026-09-14 - 2.183.0 — 2026-09-10 - 2.181.0 — 2026-09-05 - 2.179.0 — 2026-08-27 - 2.176.0 — 2026-08-09 - 2.175.1 — 2026-07-13 - 2.174.0 — 2026-06-30 - 2.157.0 — 2025-09-26 - 2.139.0 — 2024-12-15 - 2.125.0 — 2024-06-05 - 2.121.0 — 2024-02-25 - 2.120.0 — 2024-01-21 - 2.114.0 — 2023-10-02 - 2.98.1 — 2023-04-10 - … 51 more at https://npm.io/package/node-opcua-constants/versions ## README # node-opcua The most complete OPC UA stack for Node.js and the browser, written in TypeScript. [![NPM version](https://img.shields.io/npm/v/node-opcua)](https://www.npmjs.com/package/node-opcua) [![Node.js CI](https://github.com/node-opcua/node-opcua/actions/workflows/workflow.yml/badge.svg)](https://github.com/node-opcua/node-opcua/actions/workflows/workflow.yml) [![Coverage Status](https://img.shields.io/coverallsCoverage/github/node-opcua/node-opcua)](https://coveralls.io/r/node-opcua/node-opcua) [![lerna](https://img.shields.io/badge/maintained%20with-lerna-cc00ff.svg)](https://lernajs.io/) [![The Book](https://img.shields.io/static/v1?label=the%20book&message=NodeOPCUA%20by%20example&color=blueviolet&logo=leanpub)](https://leanpub.com/node-opcuabyexample-edition2024) [![NPM download - server](https://img.shields.io/npm/dm/node-opcua.svg?logo=npm&label=node-opcua-server)](https://www.npmtrends.com/node-opcua-server) [![NPM download - server -total](https://img.shields.io/npm/dt/node-opcua.svg?label=total)](https://www.npmtrends.com/node-opcua-server) [![NPM download - client](https://img.shields.io/npm/dm/node-opcua-client.svg?logo=npm&label=node-opcua-client)](https://www.npmtrends.com/node-opcua-client) [![NPM download - client -total](https://img.shields.io/npm/dt/node-opcua-client.svg?label=total)](https://www.npmtrends.com/node-opcua-client) --- ## 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 ```shell $ mkdir myproject $ cd myproject $ npm init $ npm install node-opcua ``` ### Try the sample server & client ```shell $ npm install node-opcua-samples $ ./node_modules/.bin/simple_server ``` ```shell $ ./node_modules/.bin/simple_client -e "opc.tcp://opcuademo.sterfive.com:26543" ``` ## Node.js Requirement - **Node.js 22.13** or above is required. ## Documentation [![The Book](https://img.shields.io/static/v1?label=the%20book&message=NodeOPCUA%20by%20example&color=blueviolet&logo=leanpub)](https://leanpub.com/node-opcuabyexample-edition2024) **[NodeOPCUA by Example](https://leanpub.com/node-opcuabyexample-edition2024)** — The best starting point. Dozens of practical, ready-to-use, and fully documented examples. ### Tutorials - [Create a Server](https://github.com/node-opcua/node-opcua/blob/master/documentation/creating_a_server.md) - [Create a Client in TypeScript](https://github.com/node-opcua/node-opcua/blob/master/documentation/creating_a_client_typescript.md) - [Role-Based Security & User Management (OPC 10000-18)](https://github.com/node-opcua/node-opcua/blob/master/documentation/role_based_security.md) - [Reverse Connect (OPC 10000-6 §7.1.3)](https://github.com/node-opcua/node-opcua/blob/master/documentation/reverse_connect.md) - More advanced examples and training material are available for [NodeOPCUA Subscription members](https://support.sterfive.com) ### API Reference - [API Documentation](https://node-opcua.github.io/api_doc/index.html) #### API surface The supported, semver-protected API is what the generated documentation above describes. Symbols tagged `@internal` in the source (secure-channel plumbing such as `MessageBuilder`, `ClientSecureChannelLayer`, `ServerSecureChannelLayer`, and `OPCUAServerEndPoint` construction options) are node-opcua internals: they are reachable through re-exports for historical reasons, but they may change in a minor release. Applications configure security and keys exclusively through `OPCUAClient`, `OPCUAServer`, and `OPCUACertificateManager` options. --- ## 🏢 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 | — | ✅ | [![Professional Support](https://img.shields.io/static/v1?style=for-the-badge&label=Professional&message=Support&labelColor=blue&color=green&logo=data:image/svg%2bxml;base64,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)](https://support.sterfive.com) 📧 Contact: [contact@sterfive.com](mailto:contact@sterfive.com) · 🌐 [sterfive.com](https://www.sterfive.com) --- ## Ecosystem ### AI-Powered Modeling with MCP **[node-opcua-modeler-mcp-server](https://www.npmjs.com/package/node-opcua-modeler-mcp-server)** — An [MCP server](https://modelcontextprotocol.io) 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. ```bash npx node-opcua-modeler-mcp-server ``` ### OPC UA Modeler **[OPC UA Modeler](https://github.com/node-opcua/opcua-modeler)** — Designing an information model? Write it in YAML, get standard NodeSet2.xml: create, validate, and generate OPC UA information models with full companion spec support, then load the result with `nodeset_filename`. - [Open specification, JSON Schema and example models](https://github.com/node-opcua/opcua-modeler) on GitHub - [Online NodeSet2 editor](https://opcua-modeler.sterfive.io) — nothing to install - [Documentation](https://opcua-modeler.doc.sterfive.com/), starting with [How to create a NodeSet2.xml file](https://opcua-modeler.doc.sterfive.com/docs/guides/create-nodeset2-xml) ## 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](./supported_features.md)** --- ## 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](mailto:contact@sterfive.com). --- ## :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**](https://github.com/sponsors/node-opcua) Your sponsorship ensures long-term maintenance, new features, bug fixes, and representation of the node-opcua community at the OPC Foundation. --- ## Contributors This project exists thanks to all the people who contribute. ## Contributing We welcome contributions! Here's how to get started with the source: ```shell $ 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 ```shell $ node packages/node-opcua-samples/bin/simple_server ``` ### Running the demo client from source ```shell $ node packages/node-opcua-samples/bin/simple_client.js -e "opc.tcp://opcuademo.sterfive.com:26543" ``` --- ## License node-opcua is [MIT licensed](./LICENSE). - 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](https://support.sterfive.com) for additional benefits and support. ## Copyright Copyright © 2014-2026 Sterfive SAS — 833264583 RCS ORLEANS — France ([sterfive.com](https://www.sterfive.com)) --- _Source: https://npm.io/package/node-opcua-constants · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._