Relationship Types

A relationship type defines one kind of edge between concepts. It is the difference between “these two terms are somehow related” and “Churn Rate is calculatedFrom Cancelled Subscriptions, calculatedFrom is not symmetric, and it maps to om:calculatedFrom in RDF.” Relationship types are admin-governed and global. Manage them at Settings → Governance → Glossary Term Relations.

The List

Each row shows the type’s Name, Display Name, Category, Characteristics, Cross Glossary flag, Cardinality, and Color. System-defined types carry a lock icon: they can be updated but never deleted, and their edit and delete actions are disabled. GET /api/v1/glossaryTerms/relationTypes/usage returns each type with the number of relations currently using it — check this before removing a custom type.

Creating a Type

Click Add Relation Type and fill in the panel.

Identity

Field	Notes
Name	Required, unique, immutable API key. Starts with a letter; letters and numbers only.
Display name	Required. The label drawn on graph edges and badges.
Description	What the relationship means and when to use it.

Category chip	Use for
Core	OpenMetadata’s built-in semantic relationships — `relatedTo`, `partOf`, `hasPart`, `calculatedFrom`, `usedToCalculate`, `antonym`.
OWL / SKOS	Types whose meaning is defined by a W3C standard — `broader`, `narrower`, `synonym`, `seeAlso`, `subClassOf`, `superClassOf`.
Custom · Admin-defined	Everything you add for your own domain, including types auto-registered by an ontology import.

Behavior

Characteristics are OWL property characteristics. They are not labels — reasoners and the inference engine act on them.

Characteristic	Meaning
`SYMMETRIC`	If A→B then B→A.
`ASYMMETRIC`	If A→B then never B→A.
`TRANSITIVE`	If A→B and B→C then A→C.
`FUNCTIONAL`	Each source has at most one target.
`INVERSE_FUNCTIONAL`	Each target has at most one source.
`REFLEXIVE`	Every concept relates to itself.
`IRREFLEXIVE`	No concept relates to itself.

Cardinality constrains how many concepts can sit on each end: one-to-one, one-to-many, many-to-one, many-to-many, or Custom with explicit source and target maxima (blank means unlimited). Cross-glossary controls whether the type can connect concepts belonging to different glossaries. Turn it off for types that only make sense inside a single model.

Semantics and Mapping

Field	Notes
Inverse relation	The type that represents this one in reverse — `broader` ↔ `narrower`. Symmetric types reference themselves. Used when exporting `owl:inverseOf` and when the “include inverse relationships” export option is on.
RDF predicate	The predicate emitted for authored edges, for example `http://www.w3.org/2004/02/skos/core#broader`. OpenMetadata warns if another type already claims it.
IRI	The IRI identifying the OWL object property itself.
Domain / range	Which concepts can appear on the source and target ends.
Property chain	An ordered chain of relationship types whose composition implies this one — for example `partOf ∘ partOf ⇒ partOf`.
Disjoint with	Types that can never co-occur on the same pair of concepts.
Color	Palette key for edges and badges.

Lifecycle

Field	Notes
Replaced by	Points at a successor when a type is deprecated, so consumers can follow the migration.
System-defined	Set on shipped types. Updatable, never deletable.
Entity status, owners, reviewers	Relationship types are versioned entities like any other, with full history.

The RDF predicate is the identity of this relationship in the knowledge graph and in every exported ontology. Changing it after edges exist changes what downstream consumers see. Pick it when you create the type.

Types Shipped by Default

Name	Category	RDF predicate	Characteristics
`relatedTo`	Core	`om:relatedTo`	Symmetric
`antonym`	Core	`om:antonym`	Symmetric
`partOf`	Core	`om:partOf`	—
`hasPart`	Core	`om:hasPart`	—
`calculatedFrom`	Core	`om:calculatedFrom`	—
`usedToCalculate`	Core	`om:usedToCalculate`	—
`synonym`	OWL / SKOS	`skos:exactMatch`	Symmetric
`broader`	OWL / SKOS	`skos:broader`	Transitive
`narrower`	OWL / SKOS	`skos:narrower`	Transitive
`seeAlso`	OWL / SKOS	`rdfs:seeAlso`	Symmetric
`subClassOf`	OWL / SKOS	`rdfs:subClassOf`	Transitive
`superClassOf`	OWL / SKOS	`om:superClassOf`	Transitive

Design Guidance

Prefer a few well-defined types over many similar ones

Every type is a decision modelers must make correctly on every edge. Three types used consistently beat twelve used approximately. Add a type when it unlocks a query you cannot express without it.

Set characteristics deliberately

TRANSITIVE is what lets the transitive-closure rule answer “every ancestor” in one hop. SYMMETRIC is what stops the graph from storing both directions. Leaving these unset because you are unsure means the reasoner cannot help you.

Reuse a standard predicate when one exists

Mapping to skos:broader rather than a bespoke om:isUnder makes your export intelligible to every SKOS-aware tool on the planet, for zero extra effort.

Deprecate, don't delete

Set Replaced by and leave the old type in place. Deleting a type that edges still reference destroys information no one can reconstruct.

API

Endpoint	Purpose
`GET /api/v1/relationshipTypes`	List types.
`GET /api/v1/relationshipTypes/{id}`, `/name/{fqn}`	Fetch one.
`POST` / `PUT` / `PATCH /api/v1/relationshipTypes`	Create, upsert, patch.
`DELETE /api/v1/relationshipTypes/{id}`	Delete a custom type.
`PUT /api/v1/relationshipTypes/restore`	Restore a deleted type.
`GET /api/v1/relationshipTypes/{id}/versions`	Version history.
`GET /api/v1/glossaryTerms/relationTypes/usage`	Usage counts per type.

Author (Edit mode)

Use these types to draw relations.

Reasoning & Validation

How characteristics drive inference.

Ontology & Knowledge Graph

Relationship Types | OpenMetadata Ontology

Relationship Types

The List

Creating a Type

Identity

Category

Behavior

Semantics and Mapping

Lifecycle

Types Shipped by Default

Design Guidance

API

Next

Author (Edit mode)

Reasoning & Validation

​Relationship Types

​The List

​Creating a Type

​Identity

​Category

​Behavior

​Semantics and Mapping

​Lifecycle

​Types Shipped by Default

​Design Guidance

​API

​Next

Author (Edit mode)

Reasoning & Validation

Relationship Types

The List

Creating a Type

Identity

Category

Behavior

Semantics and Mapping

Lifecycle

Types Shipped by Default

Design Guidance

API

Next