Version 0.5.1 | Working Group Draft, LF Energy Standards and Specifications
The Utility Rate Plan Exchange (URPX) ontology is an open standard for exchanging utility rate plan information using semantic web technologies (RDF, OWL, SHACL). URPX enables precise, machine-readable data exchange between utilities, regulators, vendors, and researchers.
For complete documentation, guides, and technical reference, see documentation/index.md
- Overview - Understanding URPX
- Tutorial - Step-by-step guide
- Data Dictionary - Complete reference
- Test Cases - Real-world example datasets
- FAQ - Frequently asked questions
- Core ontology:
https://urpx.org/ns/ontology/ - Core SHACL shapes:
https://urpx.org/ns/shacl/core/ - JSON-LD context artifact:
https://urpx.org/ns/context
URPX uses slash identifiers so every ontology term and SHACL shape has its own stable web identifier. The namespace site is generated with Semantic Flow, which publishes human-readable identifier pages and immutable release-tagged snapshots of the ontology, shapes, and context.
urpx/
├── documentation/ # Complete documentation (start at index)
├── ontology/ # Core OWL ontology file
├── shacl/ # SHACL validation constraints
├── context/ # Published JSON-LD context
├── skos/ # SKOS mappings to related standards
├── test-cases/ # Test datasets and examples
├── scripts/ # Project tooling
Working group development documents (tasks, specifications, working reports, roadmaps, review materials, and the worked sample instances that accompany a specification) live in urpx-org/urpx-dev.
URPX uses Semantic Versioning: MAJOR.MINOR.PATCH.
| Level | What it means for the URPX ontology |
|---|---|
| MAJOR | Breaking changes: class removals, property renames, namespace changes. Removes backward compatibility. |
| MINOR | Additive changes: new classes, new properties, new enumeration values. Backward compatible. |
| PATCH | Non-breaking corrections: annotation fixes, label typos, SHACL constraint corrections. No structural change. |
URPX is pre-1.0, and the table above describes the scheme from 1.0 onward. Until then the version digits shift down one place:
| Level | Pre-1.0 meaning |
|---|---|
MAJOR (0) |
Stays 0. The move to 1.0.0 is a deliberate statement that the vocabulary is stable and that breaking changes will carry a major bump from then on. It is not reached by accumulating releases. |
MINOR (0.x) |
Breaking changes, as described for MAJOR above. A consumer should expect to migrate between minor versions. |
PATCH (0.x.y) |
Additive and non-breaking changes, as described for MINOR and PATCH above. |
So v0.2.x to v0.3.0 was a breaking release, and a change of the term namespace is a minor bump while the vocabulary is pre-1.0.
Every release states its own compatibility in its release notes. Where a release is breaking, the notes carry a Breaking Changes section and a Migration section.
Three licenses apply by file category. Specification files (the ontology, SHACL shapes, SKOS mappings, and documentation pages) are licensed under the W3C Software Notice and Document License (W3C-20150513). Dataset files (test-case data and index files) are licensed under the Community Data License Agreement - Permissive 2.0 (CDLA-Permissive-2.0). Source code and meta files, including this README, are licensed under the Apache License, Version 2.0. See NOTICE for the full statement, LICENSE for the Apache-2.0 text, and LICENSES/ for the other two.
Licensing before and after 2026-09-09. The project-authored files in this repository were licensed under the Apache License, Version 2.0 from its first release until 2026-09-09; third-party public-record assets have carried their own notice throughout. On that date, following Working Group Draft acceptance, the category licensing above took effect: specification files moved to W3C-20150513 and dataset files to CDLA-Permissive-2.0, while source code and meta files stayed on Apache-2.0. A commit, release, or copy dated before 2026-09-09 is Apache-2.0 for every project-authored file. See TRANSITION.md for the completed transition record and the file-classification manifest.
Contributions are governed by the Developer Certificate of Origin v1.1. See CONTRIBUTING.md.
Security issues: see SECURITY.md.
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Documentation: documentation/index.md
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Bug Reports and Feedback: GitHub Issues
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Mailing List: URPX Working Group
Open standard for utility rate plan data exchange • Built on W3C semantic web standards