Markdown to RDF

This is the mechanism that makes LOKF both “markdown-friendly” and “RDF-native”.

The identity: frontmatter + context = JSON-LD

A JSON-LD document is just JSON plus an @context that maps its keys to IRIs. LOKF’s frontmatter keys are precisely the LinkML slots, and the generated lokf.context.jsonld maps each of them to its slot_uri. Therefore:

flowchart LR
    A["Concept frontmatter<br/>(YAML)"] --> C["JSON-LD document"]
    B["lokf.context.jsonld<br/>(generated @context)"] --> C
    C -- expand --> D[("RDF triples")]
    D --> E["SPARQL queries"]
    D --> F["SHACL validation"]
    D --> G["OWL reasoning"]

No new syntax, no parallel file. The author writes OKF; the context supplies the meaning.

Worked example

The frontmatter of the reference bundle’s WAU metric (abridged — see the full file), and the triples it expands to:

Frontmatter (YAML)

---
type: Metric
id: https://acme.example/knowledge/metrics/weekly-active-users
title: Weekly Active Users
unit: users
tags: [growth, engagement]
timestamp: 2026-06-30T12:00:00Z
author:
  - type: Person
    id: https://acme.example/people/jsmith
    name: Jordan Smith
measures:      [ https://acme.example/knowledge/glossary/active-user ]
derivedFrom:   [ https://acme.example/knowledge/tables/user-events ]
dependsOn:     [ https://acme.example/knowledge/glossary/active-user ]
---

RDF (Turtle, abridged)

@prefix lokf:    <https://w3id.org/lokf/> .
@prefix schema:  <http://schema.org/> .
@prefix prov:    <http://www.w3.org/ns/prov#> .
@prefix dcterms: <http://purl.org/dc/terms/> .
@prefix xsd:     <http://www.w3.org/2001/XMLSchema#> .

<…/metrics/weekly-active-users>
    a lokf:Metric ;
    schema:name "Weekly Active Users" ;
    schema:unitText "users" ;
    schema:keywords "growth", "engagement" ;
    schema:dateModified "2026-06-30T12:00:00Z"^^xsd:dateTime ;
    schema:author <…/people/jsmith> ;
    lokf:measures <…/glossary/active-user> ;
    prov:wasDerivedFrom <…/tables/user-events> ;
    dcterms:requires <…/glossary/active-user> .

<…/people/jsmith>
    a schema:Person ;
    schema:name "Jordan Smith" .

The type: Metric field became rdf:type lokf:Metric; the typed relations became prov:, dcterms:, and lokf: predicates pointing at other concepts’ IRIs.

The two aliases

The published context makes exactly two changes on top of the raw LinkML output, both standard JSON-LD keyword aliasing, so that unmodified OKF frontmatter behaves as Linked Data:

• type → @type — OKF’s required field designates the RDF class.
• id → @id — the concept’s IRI is the RDF subject.

Everything else (title, derivedFrom, tags, …) maps to its ontology property directly from the model.

Do it yourself

You never have to wire the context by hand — lokf convert (and the lokf.rdf.serialize function underneath it) does the expansion for you:

# a single concept -> Turtle on stdout
uv run lokf convert examples/acme-knowledge/metrics/weekly-active-users.md --format ttl

# the same thing behind the just recipe
just gen-rdf-turtle examples/acme-knowledge/metrics/weekly-active-users.md

--format also takes nt, jsonld, xml, n3, and trig; --output FILE writes to disk instead of stdout. Point convert at the bundle directory (examples/acme-knowledge) to project all six concepts at once.

Prefer to stay in Python? lokf.rdf.serialize is the same projection the CLI calls:

from lokf import rdf

# a concept file, or the bundle directory — either resolves IRIs correctly
print(rdf.serialize("examples/acme-knowledge/metrics/weekly-active-users.md", "ttl"))

See Convert for the full command, every output format, and the matching just recipe.