# Relationships

`RelationshipController` exposes three endpoints. The same payloads are surfaced on the source and target dataset's detail pages — when a dataset participates in any relationships, those are listed under the dataset's relationships cluster. For the cardinality model (`ONE_TO_EXACTLY_ONE` / `ONE_TO_ZERO_OR_ONE` / `ONE_TO_ONE_OR_MORE` / `ONE_TO_ZERO_ONE_OR_MORE`), the per-adapter ingestion coverage, and the ERD vs graph relationship distinction, see the [Relationships](/features/data-modelling/relationships.md) page.

| Method + Path                                                         | Operation                  | What                                                                                                |
| --------------------------------------------------------------------- | -------------------------- | --------------------------------------------------------------------------------------------------- |
| `GET /api/relationships?page=N&size=M&type=ERD\|GRAPH\|ALL&query=...` | `getRelationships`         | Paginated list with optional type filter and free-text query. Returns `DataEntityRelationshipList`. |
| `GET /api/relationships/erd/{relationship_id}`                        | `getERDRelationshipById`   | Full ERD relationship details (source / target / cardinality / owner).                              |
| `GET /api/relationships/graph/{relationship_id}`                      | `getGraphRelationshipById` | Full graph relationship details (source / target node, edge metadata).                              |

## See also

* [API Reference hub](/developer-guides/api-reference.md) — the full per-feature index.
* [Relationships](/features/data-modelling/relationships.md) — feature description, cardinality model, per-adapter ingestion coverage, ERD vs graph distinction.


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