The version-controlled ontology platform

The source of truth for your concepts.

Design, version and ship the ontology your AI and data pipelines depend on. SKOS-aligned. Graph-native. Zero PhD required.

Try free See how it works
  • SKOS / OWL / JSON-LD exports
  • Stable versioned API
  • Free tier, no credit card

  • Graph-native

    One engine for schema, taxonomy, and instances. SKOS aligned, OWL-exportable, Neo4j underneath. Not three tools stitched together.

  • Versioned

    Every change is a reversible, attributable event. Tag a snapshot. Diff two tags. Revert a mistake — without leaving the editor.

  • API-first

    Stable JSON-LD / SKOS / OWL endpoints with version pinning, language negotiation, and a built-in playground.

How it works

From schema to API in three moves.

One graph behind every view. Edit it from any side — canvas, tree, table — and ship it through the same versioned API.

Step 1

Design your T-Box.

Classes, attributes, and relation types — the schema your concepts will conform to. Every class gets the six SKOS slots for free, plus typed attributes you define.

SCHEMA · 9 classes · 13 relation types
Manufacturer
+ 4 attributes
Model
+ 4 attributes
Engine
+ 4 attributes
BodyStyle
+ 4 attributes

Step 2

Curate your taxonomies.

Concepts live in schemes. One ontology can host as many schemes as you need — Cars catalogue, body-style taxonomy, market segments — all sharing the same T-Box.

TAXONOMIES TREE
  • Toyota
  • Camry
  • Corolla
  • Honda
  • Civic
  • CR-V

Step 3

Ship to your stack.

Pin your RAG pipeline to a tagged snapshot. Negotiate language. Pick JSON-LD, SKOS Turtle, OWL XML, or CSV — every export is faithful to what's in the editor.

GET /v1/ontologies/cars/concepts
bash 
curl -X GET "https://api.semlify.com/v1/ontologies/cars/concepts \
  ?tag=v1.3 \
  &lang=en \
  &format=jsonld" \
  -H "Authorization: Bearer $ONTOLOGIA_TOKEN"

# 200 OK · application/ld+json
{
  "@context": "https://semlify.com/ctx/v1",
  "ontology": "cars",
  "tag": "v1.3",
  "data": [
    {
      "id": "c_model_camry",
      "skos:prefLabel": "Toyota Camry",
      "manufacturer": "c_mfg_toyota"
    }
  ]
}

Integrations

Plug Semlify into the stack you already run.

REST, JSON-LD, SKOS Turtle, OWL XML, webhooks, and an MCP server. The downstream side is your call.

  • LangChain
  • LlamaIndex
  • Elastic
  • Algolia
  • dbt
  • Snowflake
  • Airflow
  • Dagster
  • AWS
  • GitHub
  • Zapier
  • Notion

Don't see your tool? The REST and SKOS endpoints work with everything.

How we compare

Not the only option — but the one built for 2026.

We respect the legacy tools. We just think the next ten years of ontology work belongs in a modern multi-tenant SaaS with version control built in.

Capability Semlify Protégé PoolParty Sheets / wiki
T-Box editor (classes + relations)
Multi-taxonomy in one ontology
Versioned change history with revert
Tags + tag-to-tag diffs
Stable JSON-LD / SKOS / OWL API
Multi-tenant SaaS (no install)
Live validation panel
AI helpers (synonyms, translations, dupes)
Free tier

← swipe to see all columns →

Comparison reflects April 2026 product capabilities as we understand them. If you spot something inaccurate, tell us — we keep this honest.

Frequently asked

Questions we get every week.

How is this different from Atlan or Collibra? +
Data catalogs document the tables and columns you already have. Semlify documents the concepts those tables try to represent — and serves them through a typed, versioned graph. We're upstream of the catalog. Many teams run both.
Is this just Protégé in the cloud? +
No — Protégé is a desktop OWL editor for the academic ontology community. Semlify is multi-tenant SaaS for product teams, with version control, drag-drop reparenting, multilingual labels, an API, and a validation panel. We export OWL faithfully, so an architect using Protégé can open our exports — but the day-to-day shape of work is different.
Do you support OWL? +
Yes — we export full OWL/RDF/XML for any ontology, and the AI tab includes class suggestion that can populate a basic OWL shape from labels. Description-logic inference is on the roadmap.
Where does the data live? +
Postgres for tenant data, billing, members. Neo4j Aura for the graph. EU and US regions; Pro and above pick at workspace creation. Enterprise can pin to a dedicated single-region cluster or self-host.
Will you lock me in? +
No. Every ontology exports faithfully to JSON-LD, SKOS Turtle, OWL RDF/XML, and CSV. The exports round-trip — you can re-import them anywhere that speaks SKOS or OWL. Your concepts are yours.

Stop arguing about what your concepts mean.

Start versioning them. Free workspace, no credit card.

Try free Talk to sales