OpenMetadata/openmetadata-docs/content/v1.7.x/developers/custom-properties.md

title	slug
How to Add a Custom Property to an Entity with API	/developers/how-to-add-custom-property-to-an-entity

How to Add a Custom Property to an Entity with API

This tutorial will create a custom property for a table entity.

A custom property can store a value for each entity, such as a table's size for each table entity.

Step 1: Get the table entity type.

All OpenMetadata APIs are secured so make sure to add the proper headers. API requests can be sent with your JWT token

curl -X GET http://localhost:8585/api/v1/metadata/types/name/table

After the API call, you will get a response like this.

{
  "id": "7f0b032f-cdc8-4573-abb0-22165dcd8e07",
  "name": "table",
}

Take note of the id that corresponds to "name": "table" from the above response... 7f0b032f-cdc8-4573-abb0-22165dcd8e07.

Step 2: Get the field types with category=field

OpenMetadata's UI supports three field types:

• String
• Markdown
• Integer

 curl -X GET http://localhost:8585/api/v1/metadata/types?category=field&limit=20

This API call will return available field types, grab the id of the "name": "string" field type. i.e 7531f881-c37c-4e39-9154-4bdf0802e05e

Step 3: Make a call to create the custom property for the table entity

Create a payload using the field type id from the previous step and send a PUT request to the table id from the first request to create the custom property for tables.

curl -X PUT http://localhost:8585/api/v1/metadata/types/7f0b032f-cdc8-4573-abb0-22165dcd8e07 \     #table id from step 1
-H "Content-Type: application/json" \
-d '{
  "description": "Property for tracking the tableSize.",
  "name": "tableSize",
  "propertyType": {
    "id": "7531f881-c37c-4e39-9154-4bdf0802e05e",                                                  #string field type id from step 2
    "type": "type"
  }
}'

Step 4: Get the custom properties for the table entity

Verify the previous step with the following request. Look in "customProperties" for our new property.

curl -X GET http://localhost:8585/api/v1/metadata/types/name/table?fields=customProperties

Response

{
  "id": "7f0b032f-cdc8-4573-abb0-22165dcd8e07",
  "name": "table",
  "customProperties": [
    {
      "name": "tableSize",
      "description": "Property for tracking the tableSize.",
      "propertyType": {
        "id": "7531f881-c37c-4e39-9154-4bdf0802e05e",
        "type": "type",
        "name": "string",
        "fullyQualifiedName": "string",
        "description": "\"A String type.\"",
        "displayName": "string",
        "href": "http://localhost:8585/api/v1/metadata/types/7531f881-c37c-4e39-9154-4bdf0802e05e"
      }
    }
  ]
}

So for all table entities, we have a tableSize custom property available now, let’s add the value for it for the raw_product_catalog table.

Step 5: Add/Edit the value of the custom property for the entity.

All the custom properties value for the entity will be stored in the extension attribute.

Let’s assume you have raw_product_catalog table, find it's id with the API call below.

curl -X GET http://localhost:8585/api/v1/tables?limit=1000

If the table's id was 208598fc-bd5f-458c-bf98-59224e1620c7 and we are adding a value to the custom property for the first time, our PATCH API request will be like this.

curl -X PATCH http://localhost:8585/api/v1/tables/208598fc-bd5f-458c-bf98-59224e1620c7 \
--header 'Content-Type: application/json-patch+json' \
--data '[
  {
    "op": "add",
    "path": "/extension",
    "value": {
      "tableSize": "50GB"
    }
  }
]'

When Changing the value of the custom property the request should be like this,

curl -X PATCH http://localhost:8585/api/v1/tables/208598fc-bd5f-458c-bf98-59224e1620c7 \
--header 'Content-Type: application/json-patch+json' \
--data '[
  {
    "op": "replace",
    "path": "/extension/tableSize",
    "value": "60GB"
  }
]'

When finished your new custom property should be present and updated for the raw_product_catalog table

{% image src="/images/v1.7/developers/custom-properties.png" alt="Custom property added to table" caption=" " /%}

Step 5: Delete custom property.

To finish this tutorial, delete the newly created custom property, tableSize by going to Settings >> Custom Properties >> Tables.

Click Delete Property, then Confirm.

{% image src="/images/v1.7/developers/delete-custom-properties.png" alt="Delete custom property added to table" caption=" " /%}