SDK · Java
OPC UA in Java
Eclipse Milo is the mainstream JVM OPC UA stack, client and server, targeting the 1.05 specification family. It is the obvious choice inside an existing Java or Kotlin platform, and it runs the public demo server many of this site's examples use.
| Project | eclipse-milo/milo |
|---|---|
| Version | 1.1.6 |
| Licence | EPL |
| Install | Maven: org.eclipse.milo:milo-sdk-client |
What to know before you start
- Requires JDK 17 to build; runtime-compatible with 17 and later.
- Artifacts were renamed to milo-sdk-client and milo-sdk-server: older tutorials reference the previous names.
- The README on the default branch has lagged the tags before. Trust the tag you are building against, not the front page.
- Eclipse Public Licence, which is generally straightforward for commercial use.
Recipes for this stack are not published yet. The twelve-task recipe matrix currently covers Python, Node.js, C#/.NET and C. The concepts are identical across stacks: start from the Python recipes and map the calls.
Last verified 7 September 2026 against OPC UA 1.05.07. Version read from the project release tags. OPC UA Connect is an educational resource and is not affiliated with the OPC Foundation.