This guide shows you how to add [strategy constraints](../reference/strategy-constraints) to your feature flags using the Admin UI. For information on how to interact with strategy constraints from an [Unleash client SDK](../reference/sdks), visit the specific SDK's documentation or see [the relevant section in the strategy constraints documentation](../reference/strategy-constraints#sdks).
You'll need to have an existing feature flag with a defined strategy to add a constraint. The rest of this guide assumes you have a specific strategy that you're working with.
Refer to [the _constraint structure_ section of the strategy constraints reference](../reference/strategy-constraints#constraint-structure) for a thorough explanation of the constraint fields.
1. From the "Context Field" dropdown, **select the context field** you would like to constrain the strategy on and **choose the [constraint operator](../reference/strategy-constraints#strategy-constraint-operators)** you want.
2.**Define the values** to use for this constraint. The operator you selected decides whether you can define one or multiple values and what format they can have.
