uml4net-sage

Claude plugin providing grounded, spec-accurate answers about UML, backed by a knowledge base built from the OMG UML specification, the metamodel and uml4net.

Sage is the AI agent of the uml4net ecosystem: a bridge between engineers and the UML 2.5.1 specification. It reads the OMG UML metamodel XMI, the Standard Profile, and (optionally) the specification PDF - all fetched fresh on your own machine, never redistributed by this plugin - and answers questions grounded in that data instead of general training knowledge.

Install

/plugin marketplace add STARIONGROUP/uml4net-sage
/plugin install uml4net-sage@uml4net

Nothing is downloaded at install time - OMG's specification files aren't redistributed here (see Specifications & licensing). On first use, ask Claude to set up the knowledge base, or run directly:

uml4net-sage fetch --version 2.5.1     # XMI + specification PDFs, from omg.org
uml4net-sage generate --version 2.5.1  # builds the knowledge base

Pass --no-specs to fetch to skip the PDFs - metamodel/Standard Profile lookups still work fully; only verbatim specification citation needs them.

What it knows

Skill	Example prompt
metamodel-lookup	"What features does Classifier own and inherit?" / "What's the opposite end of Class::nestedClassifier?"
standard-profile-lookup	"What does the «Trace» stereotype mean?"
uml-spec-citation	"What does the UML spec say about generalization?"
xmi-spec-citation	"What does the XMI standard say about href vs idref?"
xmi-schema-lookup	"What attributes does XMI's Extension element support?"
uml-xmi-model-inspection	"Check this XMI file against the metamodel: path/to/model.xmi"
knowledge-setup	"Is the UML knowledge base fetched and generated?"

Answers are tagged by provenance: NORMATIVE (a verbatim spec quote), MODEL (read directly from the metamodel/Standard Profile XMI), or DERIVED (computed here, e.g. a clause number cited without the PDF available).

Releases

One UML version is relevant today - 2.5.1 - fetched from a fixed, static set of OMG URLs (see sources/README.md). Unlike specifications with a rolling release cadence, there's no update-checking machinery here: if OMG ever ships a new UML version, a maintainer adds one entry to Uml4Net.Sage.Knowledge.KnownUmlVersions and cuts a new plugin release - a deliberate, human-in-the-loop step rather than automated discovery. The companion OMG XMI specification (also 2.5.1 today, by coincidence - it versions independently) is tracked the same way, in Uml4Net.Sage.Knowledge.KnownXmiVersions.

The knowledge base

Generated locally, never committed - see knowledge/README.md for the full file layout and CLAUDE.md's "Committed vs git-ignored" for why. In short: metamodel/ and standard-profile/ are markdown + JSON derived from OMG's metamodel XMI (structural facts, not the specification's copyrighted prose); spec/ (present once the PDFs are fetched and extracted) holds the specification's own text and is treated identically to the source PDFs for licensing purposes - generated locally, never committed, never redistributed. knowledge/xmi/<version>/spec/ holds the same for the companion OMG XMI specification (the serialization standard UML models are themselves written in) as a top-level sibling, since it versions independently of UML.

If you have jq installed, skills use it to query knowledge/<version>/metamodel/metamodel.json directly for set/closure-shaped questions (e.g. "every concrete subclass of Classifier") - faster and cheaper than reading every element's markdown page. Without jq, they fall back to Grep/Read.

Specifications & licensing

The OMG UML 2.5.1 specification PDF, its four metamodel XMI files, and the companion OMG XMI 2.5.1 specification PDF are copyrighted by OMG and its member companies (see NOTICE for the full list and license terms) and are never committed to this repository or bundled with any release - uml4net-sage fetch downloads them fresh, directly from omg.org, onto your own machine:

• UML Specification PDF: https://www.omg.org/spec/UML/2.5.1/PDF
• Abstract Syntax Metamodel XMI: https://www.omg.org/spec/UML/20161101/UML.xmi
• Primitive Types XMI: https://www.omg.org/spec/UML/20161101/PrimitiveTypes.xmi
• Standard Profile XMI: https://www.omg.org/spec/UML/20161101/StandardProfile.xmi
• Diagram Interchange Metamodel XMI: https://www.omg.org/spec/UML/20161101/UMLDI.xmi
• XMI Specification PDF: https://www.omg.org/spec/XMI/2.5.1/PDF

See sources/README.md for the full provenance table and NOTICE for OMG's complete licensing terms.

Development

This repository contains both the plugin (shipped) and the toolchain that generates its knowledge base (not shipped - see tools/README.md). See CLAUDE.md for build/test commands, architecture, and conventions.