appwrite/docs/examples/1.5.x/server-rest/examples/databases/create-relationship-attribute.md

POST /v1/databases/{databaseId}/collections/{collectionId}/attributes/relationship HTTP/1.1 Host: <REGION>.cloud.appwrite.io Content-Type: application/json X-Appwrite-Response-Format: 1.6.0 X-Appwrite-Project: <YOUR_PROJECT_ID> X-Appwrite-Key: <YOUR_API_KEY>

{ "relatedCollectionId": "<RELATED_COLLECTION_ID>", "type": "oneToOne", "twoWay": false, "key": , "twoWayKey": , "onDelete": "cascade" }