Linked Open Knowledge Format

A semantic profile of Google's Open Knowledge Format — write OKF markdown, get a queryable knowledge graph for free.

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LOKF keeps OKF’s markdown-plus-frontmatter authoring model but binds every concept, field, and relationship to schema.org, W3C DCAT, and W3C PROV-O, so a bundle of markdown files is also valid JSON-LD that expands losslessly to RDF. The format is defined once in LinkML; the JSON-LD context, JSON Schema, SHACL shapes, and OWL ontology are all generated from that single source.

A concept at a glance

Ordinary OKF markdown, where every key has a defined RDF meaning:

---
type: Metric                                    # -> rdf:type lokf:Metric
id: https://acme.example/knowledge/metrics/weekly-active-users   # -> @id (subject)
title: Weekly Active Users                       # -> schema:name
unit: users                                      # -> schema:unitText
timestamp: 2026-06-30T12:00:00Z                  # -> schema:dateModified
derivedFrom: [ .../tables/user-events ]          # -> prov:wasDerivedFrom
dependsOn:   [ .../glossary/active-user ]        # -> dcterms:requires
measures:    [ .../glossary/active-user ]        # -> lokf:measures
---
# Definition
Distinct users with a qualifying event in a trailing 7-day window.

Attach the published lokf.context.jsonld and this expands to RDF triples using schema:, prov:, dcterms:, and lokf: predicates — no separate file.

Convert

lokf convert projects a concept or a whole bundle to Turtle, N-Triples, JSON-LD, or RDF/XML.

Query

lokf query runs SPARQL over a bundle loaded into an in-process Oxigraph store.

Serve

lokf serve publishes a local SPARQL endpoint and a live graph explorer.

Automate

An MCP server and bundled agent skills let agents drive the whole toolkit.