Entity browser

Schema:

{
  "type": "object",
  "properties": {
    "type": {
      "type": "string",
      "pattern": "^form-field$"
    },
    "id": {
      "type": "string",
      "pattern": "^[0-9a-f]{8}-([0-9a-f]{4}-){3}[0-9a-f]{12}$"
    },
    "machine_name": {
      "type": "string"
    },
    "data": {
      "type": "object",
      "properties": {
        "uid": {
          "type": "string",
          "pattern": "^form-entity-browser$"
        },
        "title": {
          "type": "string"
        },
        "value": {
          "type": "object",
          "properties": {
            "entity": {
              "type": "object",
              "properties": {
                "entityType": {
                  "type": "string"
                },
                "entityUUID": {
                  "type": "string"
                },
                "entityId": {
                  "type": "string"
                }
              }
            },
            "settings": {
              "type": "object",
              "properties": {
                "entityBrowserType": {
                  "type": "string"
                },
                "entityType": {
                  "type": "string"
                },
                "bundles": {
                  "type": "object"
                }
              }
            },
            "jsonapi_link": {
              "type": "string"
            }
          }
        }
      }
    }
  },
  "required": [
    "id",
    "type",
    "data"
  ]
}

Example output:

Given "Entity browser" form element on a component set up like so

And used on Node layout canvas like so

JSON:API output for this form field will be this:

{
  "type": "form-field",
  "id": "69922b59-2b5a-4673-a5b5-ea57c0d83ff3",
  "machine_name": "entity-browser",
  "data": {
    "uid": "form-entity-browser",
    "title": "Entity browser",
    "value": {
      "entity": {
        "entityType": "media",
        "entityUUID": "79611cf8-0a54-4d6d-aebd-8f77a159acd5",
        "entityId": "79611cf8-0a54-4d6d-aebd-8f77a159acd5"
      },
      "settings": {
        "options": {
          "entityBrowserType": "media_library",
          "entityType": "media",
          "bundles": {
            "acquia_dam_image_asset": true
          }
        }
      },
      "jsonapi_link": "https://sitestudiodocs.acquia.com/jsonapi/media/acquia_dam_image_asset/79611cf8-0a54-4d6d-aebd-8f77a159acd5"
    }
  }
}

In this example "value" object contains "jsonapi_link" property as the "Entity browser" form field stores reference to a Media library entity. The value of "jsonapi_link" property is an absolute url pointing to a JSON:API Resource for referenced media entity with uuid "79611cf8-0a54-4d6d-aebd-8f77a159acd5".