Unit of Measurement

Standardized unit of measurement codes following international standards (such as UN/ECE Recommendation 20) for consistent measurement handling and validation.

The ref_uom Object

Unit of measurement collection provides standardized unit codes and classifications for proper measurement handling, validation, and conversion throughout the system.

Field Name	Type	Description
code	string	Primary key. Unit of measurement code following international standards (e.g., "ACR", "BLL", "4H").
user_created	object	User who created the unit of measurement record. Read-only. Links to directus_users.
date_created	datetime	Timestamp in ISO 8601 when the unit of measurement record was created. Read-only.
user_updated	object	User who last updated the unit of measurement record. Read-only. Links to directus_users.
date_updated	datetime	Timestamp in ISO 8601 when the unit of measurement record was last updated. Read-only.
description	string	Human-readable description of the unit of measurement.
classification	string	Classification category of the unit (e.g., "length", "area", "volume", "density").
status	string	Record status. Default: "published". Values: "draft", "published".

---

List Units of Measurement

List existing units of measurement.

REST

GET /items/ref_uom

GraphQL

query {
  ref_uom {
    code
    description
    classification
    status
    date_created
    date_updated
  }
}

Query Parameters

Supports all global query parameters.

Returns

An array of up to limit unit of measurement objects. If no items are available, data will be an empty array.

---

Retrieve a Unit of Measurement

Retrieve a specific unit of measurement by code.

REST

GET /items/ref_uom/:code

GraphQL

query {
  ref_uom_by_id(id: "uom_code") {
    code
    description
    classification
    status
    user_created {
      id
      first_name
      last_name
    }
    date_created
    user_updated {
      id
      first_name
      last_name
    }
    date_updated
  }
}

Returns

Returns a unit of measurement object if a valid code was provided.

---

Create a Unit of Measurement

Create a new unit of measurement.

REST

POST /items/ref_uom

{
  "code": "CX",
  "description": "Custom unit",
  "classification": "custom",
  "status": "draft"
}

GraphQL

mutation {
  create_ref_uom_item(data: {
    code: "CX"
    description: "Custom unit"
    classification: "custom"
    status: "draft"
  }) {
    code
    description
    classification
    status
  }
}

Query Parameters

Supports all global query parameters.

Request Body

A partial unit of measurement object.

Returns

Returns the unit of measurement object for the created unit of measurement.

---

Update a Unit of Measurement

Update an existing unit of measurement.

REST

PATCH /items/ref_uom/:code

{
  "description": "Updated unit description",
  "status": "published"
}

GraphQL

mutation {
  update_ref_uom_item(id: "uom_code", data: {
    description: "Updated unit description"
    status: "published"
  }) {
    code
    description
    status
  }
}

Query Parameters

Supports all global query parameters.

Request Body

A partial unit of measurement object.

Returns

Returns the unit of measurement object for the updated unit of measurement.

---

Delete a Unit of Measurement

Delete an existing unit of measurement.

REST

DELETE /items/ref_uom/:code

GraphQL

mutation {
  delete_ref_uom_item(id: "uom_code") {
    code
  }
}

Returns

Empty body.

---

Sample Data

Code	Description	Classification	Status
23	grams per cubic centimeter	density	published
4H	micrometre	length, breadth, height, thickness, radius, radius of curvature, cartesian coordinates, diameter, length of path, distance	published
ACR	acre	area	published
BLD	dry barrel (US)	volume	published
BLL	barrel (US)	volume	published