Web of Things (WoT) OPC UA Binding

[sebastiankb]

Name of the Binding

Web of Things (WoT) OPC UA Binding

Link to the binding document

https://reference.opcfoundation.org/WoT/Binding/v100/docs/

Binding Prefix

uav

Binding Identification

"base": "opc.tcp://..." and/or
"href": "opc.tcp://..."

Supported TD version

• V1.0
• V1.1
• V2.0

Binding Version

2026-01-08

Summary of the Binding

This binding specifies an official OPC UA binding for the W3C Web of Things (WoT). WoT Thing Description can be specified with relevant OPC UA metadata that provides information such as how to access an OPC UA server and its datapoints (UA variables) and methods, as well as the security requirements.

Example:

{
    "@context": [
        "https://www.w3.org/2022/wot/td/v1.1",
        {
            "uav": "http://opcfoundation.org/UA/WoT-Binding/",
            "1": "http://example.nsu.com/demo/pump"
        }
    ],
    "@type": [
        "Thing",
        "uav:object"
    ],
    "base": "opc.tcp://opcuademo.com:4840",
    "securityDefinitions": {
        "auto_sc": {
            "scheme": "auto"
        }
    },
    "security": "auto_sc",
    "title": "Demo OPC UA Server Pump",
    "uav:browseName": "1:Pump",
    "properties": {
        "pumpSpeed": {
            "@type": "uav:variable",
            "title": "Pump speed",
            "type": "number",
            "observable": true,
            "uav:browseName": "1:PumpSpeed",
            "forms": [
                {
                    "href": "/?id=ns=1;s=PumpSpeed",
                    "op": [
                        "readproperty",
                        "writeproperty",
                        "observeproperty"
                    ],
                    "uav:browsePath": "/Root/Objects/1:Pump/1:PumpSpeed",
                    "contentType": "application/octet-stream"
                }
            ]
        }
    }
}

[egekorkan]

Note: This is a test review that is strict according to the current editor's draft. We will improve the process. We aware that this is too strict maybe but that will improve.

Reviewers: Simulated as WoT TD TF

Issues detected:

• The binding MUST contain the following sections in the order presented below. is not respected. It is not easy to find where the binding is when that is not followed.
• The table with vocabulary mappings to operations is not found. We have found https://reference.opcfoundation.org/WoT/Binding/v100/docs/6.5.3 but that does not contain uav:method
• Default and possible mappings not found
• Examples are only images (this is ok according to the rules)
• There is no JSON Schema we could find: https://w3c.github.io/wot-binding-registry/#req-docs . This is a requirement
• There is no JSON-LD Context, that is fine according to rules
• The summary does not conform to https://w3c.github.io/wot-binding-registry/#req-summ (this will be fixed on our side)