Reference

Applies to Milo 1.2.0-SNAPSHOT. Source baseline 7faaf4f05, 2026-10-04.

Reference pages hold the exact rules and values that the tutorials and guides rely on. Use them when you know what you are building and need a precise answer. For dependencies, start with Getting started, and for complete programs, see the Examples learning paths.

Reference pages

• Data types: map OPC UA types to Java values, including unsigned values, arrays, matrices, and custom structures you discover, decode, or register a codec for.
• Encodings: encode and decode values yourself, for example to store them, round-trip an ExtensionObject, produce JSON, or migrate 1.1 JSON and custom codecs.
• Security policies: choose a security policy and message security mode for an endpoint, see which policy families Milo supports, and match user-token policies to endpoints.
• Configuration reference: look up the units, defaults, and interactions of client, server, endpoint, subscription, encoding-limit, and executor settings.
• Capabilities and limitations: before you choose an integration approach, see what Milo provides, what your application must supply, and which modules, transports, and companion specifications are in scope.

Elsewhere in the guide

• OPC UA concepts defines the vocabulary that the reference pages use.
• The feature guides, Reverse Connect, GDS client, and Alias Names, explain those features from setup to cleanup.
• Server topics such as Sampling, Access control, Types and instantiation, and Alarms and Conditions belong to the Server SDK guide.
• Deployment, Troubleshooting, and Diagnostics and Wireshark help once a program is running or failing.
• Release notes list new features and migration steps by release.

API reference

These links open source files at the guide's baseline commit. Read their Javadoc comments for API details.

• OpcUaClient
• OpcUaServer

Executable examples live in the source repository, and Examples indexes them by topic.