A W3C standardisation effort that applies web architecture, protocols, and semantics to the Internet of Things, describing physical devices through machine-readable Thing Descriptions based on JSON-LD so that heterogeneous sensors, actuators, and services can be discovered, composed, and controlled through uniform web interfaces regardless of the underlying transport protocol, providing an interoperability layer that bridges fragmented IoT ecosystems and makes device capabilities legible to software agents.
Semantic Classification
Content
Definition
The Web of Things (WoT) is the World Wide Web Consortium’s answer to IoT fragmentation: rather than inventing yet another device protocol, it layers the web’s proven architectural style — URIs for identification, hypermedia for discovery, standard verbs for interaction — over whatever protocols devices already speak. Its centrepiece is the Thing Description (TD), a JSON-LD document that declares a device’s properties (readable/observable state such as temperature), actions (invocable operations such as toggling a relay), and events (asynchronous notifications), together with the security schemes and protocol bindings needed to reach them. A TD makes a thing self-describing: any consumer that can parse the description can interact with the device without prior, vendor-specific integration.
Because Thing Descriptions are JSON-LD, they inherit Semantic Web machinery. Terms can be annotated with ontologies (the iot.schema.org vocabulary, SAREF, domain ontologies for buildings or agriculture), enabling semantic search — “find every occupancy sensor on this floor” — and automated composition of devices that were never designed together. The WoT Binding Templates map the abstract interaction model onto concrete protocols (HTTP, CoAP, MQTT, Modbus), while the WoT Scripting API and open-source runtimes such as Eclipse Thingweb node-wot give developers a uniform programming surface. W3C published the core WoT Architecture and Thing Description specifications as Recommendations in 2020, with version 1.1 following in 2023.
In this knowledge graph, WoT matters chiefly as a bridging construct: it is the standardised device-capability layer that agentic systems can consume. Where an Agent-to-Agent Protocol lets software agents advertise and negotiate capabilities with one another, WoT does the equivalent for physical endpoints — a Thing Description plays the same role for a lamp or a robot arm that an agent card plays for a service, and the two vocabularies together sketch a web in which agents discover and orchestrate both digital and physical actors.
Current Landscape
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Thing Description 2.0 reached First Public Working Draft on 4 November 2025 on the W3C Recommendation track; it continues the work of TD 1.1 (a Recommendation of 5 December 2023) with no guarantee of backwards compatibility, and the draft charter targets a Candidate Recommendation transition around Q4 2027 and a Recommendation around June 2028.
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Binding Templates retired in favour of a Binding Registry: alongside TD 2.0 the Working Group replaced the WoT Binding Templates Group Note with the WoT Binding Registry and published an updated Working Draft of WoT Profiles (for out-of-the-box interoperability).
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Governance churn: co-Chair Michael McCool stepped down on 8 May 2025 and Dave Raggett became Team Contact; the WoT WG charter was extended to 2 April 2026.
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Adoption remains strongest in industrial and smart-building integration, where WoT acts as a neutral overlay above brownfield protocols (Siemens, Oracle, and Intel contributed heavily, and Eclipse Thingweb node-wot is the reference implementation).
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WoT deliberately complements rather than competes with transport-level ecosystems: Matter standardises the radio-to-application stack for consumer devices, whereas WoT standardises description and interaction metadata and can wrap Matter, OPC UA, or proprietary APIs alike; interest from the agentic-AI community in machine-readable capability descriptions has renewed attention on the standard.
Sources:
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https://www.w3.org/news/2025/first-public-working-draft-web-of-things-wot-thing-description-2-0/