unleash.unleash/website/docs/how-to/how-to-define-custom-context-fields.md

---
title: How to define custom context fields
---

:::info Availability
Custom context fields are an Enterprise-only feature and were introduced in Unleash 3.2.28.
:::

This guide shows you how to create [custom context field for the Unleash Context](../user_guide/unleash-context.md#custom-context-fields). You can use custom context fields for [strategy constraints](../advanced/strategy-constraints.md) and for [custom stickiness calculations](../advanced/stickiness.md#custom-stickiness).

## Step 1: Navigate to the context field creation form {#step-1-navigate-to-context-fields}

In the Unleash Admin UI, navigate to the _context fields_  page:
1. Click the "Configure" button in the top menu to open the configuration dropdown menu.
2. Click the "Context fields" menu item.

    ![A visual representation of the tutorial steps described in the preceding paragraph, showing the interaction points in the admin UI in order.](/img/context-fields.png)

3. On the context fields page, click the "add new context field" button.

    ![The ]( /img/context-field-create-button.png)

## Step 2: Define the new context field {#step-2-define-new-context-field}

Define the custom context field by filling out the form. You must at least the field a unique _name_. Everything else is optional. Refer to the [custom context field reference guide](../user_guide/unleash-context.md#custom-context-fields) for a full overview of the parameters and their functions and requirements.

When you are satisfied with the context field's values, use the "Create" button to submit the form and save the context field.

![New context fields](/img/new_context_field.png)

#### What is “legal values”? {#what-is-legal-values}

Legal values defines all possible values for the context field. this will be used in Unleash Admin UI to guide users when working with context fields to make sure they only use legal values.