ster

Software

Dependencies

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  [ Breton: "Meaning" or "Sense" ]
  [  Semantic Knowledge Editor  ]

ster is a terminal editor for semantic knowledge bases. Build and explore SKOS taxonomies and OWL ontologies together in one full-screen TUI — then visualise them as interactive graphs, run SPARQL, and publish HTML documentation, all from your terminal. No database required.

ster is the Breton word for meaning, with homonyms for river and star — keep the flow, and follow your star.

The TUI

The heart of ster is a Textual terminal app that shows your SKOS taxonomy and OWL ontology in a single tree:

• One unified tree — concept schemes, concepts, classes, named individuals, and properties side by side. Create, rename, delete, and edit any entity inline; every field is editable in a detail panel.
• Puns (class ⇔ concept) — an entity can be both an OWL class and a SKOS concept. Promote a concept to a class or demote it back with one action.
• Tag individuals with concepts — link named individuals to SKOS concepts (dcterms:subject), one at a time or in bulk from a checklist.
• Live quality & coverage — a semanticlint pass colour-codes each tree node by its worst issue (🔴 error · 🟠 warning); hover for a per-entity issue count, and open the node to see the full list and its label/comment/property-fill coverage.
• Markdown notes — attach rich notes to any entity with a full-screen editor and a live rendered preview; markdown links are URL-checked when you open or edit them.
• Ontology overview — editable title/description; opening a pure-OWL file jumps straight to the overview.
• Bundled demo — a mixed SKOS + OWL sandbox you can load from the file list to try everything out (it resets on each load).

Beyond the tree

Every capability below is reachable from the home menu, acting on the file you selected:

Installation

ster is a CLI app, so the cleanest install is as an isolated uv tool — no virtualenv to manage, ster goes straight on your PATH:

uv tool install ster        # install
uv tool upgrade ster        # update to the latest release
uvx ster                    # or run once, without installing

Prefer pip? That works too:

pip install ster            # install / upgrade with: pip install -U ster

That's everything — TUI editing, graph viewer, SPARQL, HTML export, and the publish server, no extras required. AI-assisted concept suggestions are available via the llm library (online models, local Ollama models, or a no-model copy-paste mode).

Quick start

ster

The home screen lists the ontology and taxonomy files in the current directory (plus a Load demo entry). Pick a file, then choose an action:

  Select a file:
    ☑  my-ontology.ttl
    🎒 Load demo ontology / taxonomy

  ▶  🖥  TTL Viewer-Editor
     🔍 SPARQL Query
     📦 Linked Data Publish & Version
     🌐 HTML Data Catalog
     ◈  Load Graph Viewer
     📥 Import External Ontology
     ✕  Quit

Arrow keys navigate; Enter confirms. Inside the tree editor, press ? for the full keymap — the essentials are + add, d delete, e edit, Enter expand/open, Esc back.

Supported formats

Large Files & Performance

For large ontologies or taxonomies (over 100k triples), ster provides several performance boosts out of the box:

• Fast Rust Parsing: ster uses the high-performance Oxigraph engine automatically for near-instant RDF parsing.
• N-Triples Acceleration: Reading .nt files is significantly faster than Turtle for massive datasets. Use ster convert large.ttl large.nt to switch.
• Binary Caching: After the first successful parse, a secure binary cache is created. Subsequent loads are near-instant (typically under 2s for 150MB+ files).

Key dependencies

Development

See CONTRIBUTING.md for the full workflow.

git clone https://github.com/gbelbe/ster.git
cd ster
uv sync --extra dev
bash scripts/install-hooks.sh   # git pre-push hook (once per clone)
bash scripts/ci.sh              # full local gate: lint · types · security · tests · coverage

The local gate mirrors GitHub Actions (ruff · mypy · bandit + pip-audit · pytest on Python 3.11 / 3.12 / 3.13), and a pre-push hook blocks any push without a passing run in the last 60 minutes. Coverage is reported to Codecov.

Release notes live in the GitHub releases.

License

MIT