# Get a Derived Column

Endpoint: GET /1/derived_columns/{datasetSlug}/{derivedColumnId}
Version: 1.0.0
Security: configuration_key

## Path parameters:

  - `datasetSlug` (string, required)
    The dataset slug or use  for endpoints that support environment-wide operations.

  - `derivedColumnId` (string, required)
    Unique identifier (ID) of a Calculated Field (also called a Derived Column).

## Response 200 fields (application/json):

  - `id` (string, required)
    Unique identifier (ID), returned in response bodies.

  - `alias` (string, required)
    The human-readable name of the Calculated Field (also called Derived Column), as it will be referenced when building queries.

  - `expression` (string, required)
    The expression to evaluate to construct this Calculated Field's value. (Calculated Field is also called Derived Column.) Refer to the [Calculated Field Reference](https://docs.honeycomb.io/reference/derived-column-formula/).

  - `description` (string)
    A human-readable description for the Calculated Field that displays in the UI.

  - `created_at` (string, required)
    ISO8601 formatted time when the field was created.

  - `updated_at` (string, required)
    ISO8601 formatted time when the field was updated.

## Response 400 fields (application/problem+json):

  - `error` (string, required)

  - `status` (number, required)
    The HTTP status code of the error.

  - `type` (string, required)
    Type is a URI used to uniquely identify the type of error.

  - `title` (string, required)
    Title is a human-readable summary that explains the  of the problem.

  - `detail` (string)
    The general, human-readable error message.

  - `instance` (string)
    The unique identifier (ID) for this specific error.

## Response 401 fields (application/json):

  - `error` (string)

## Response 404 fields (application/json):

  - `error` (string)

## Response 429 fields (application/json):

  - `error` (string)