# Targeting

> Configure rollout within an environment

## Minimum version

You can configure a feature flag to require a minimum version before being enabled in an environment. The flag will be enabled once that version (or any later version) is deployed to that environment.

![Screenshot of feature flag environment drawer, minimum version section is expanded, minimum version input has value 12.1.0](/docs/img/feature-toggles/minimum-version.png)

## Tenants {#tenants}

If your project uses [Tenants](/docs/tenants/), you can configure a feature flag to be enabled for subsets of your tenants within an environment.

There are many options for configuring a feature flag for tenants. These are all modeled in Octopus and do not require any custom configuration in application code.

### Excluded tenants

You can exclude tenants individually or exclude groups of tenants using tenant tags. Excluded tenants will always override any other rollout configuration, even if the rollout percentage is set to 100%.

![Screenshot of feature flag environment drawer, excluded tenants section expanded, tenants to exclude multi-select has Acme Corporation and Contoso Ltd tenants selected, tenant tags to exclude multi-select has Tier/Enterprise tag selected](/docs/img/feature-toggles/excluded-tenants.png)

Once a feature flag is configured with an excluded tenant tag, any changes to tenant tag assignments apply immediately to feature flags (no update to the feature flag configuration is required).

### Included tenants

You can enable feature flags for individual tenants. These tenants will always be included, even if the tenant rollout percentage is set to 0%.

![Screenshot of feature flag environment drawer, included tenants section expanded, tenants to include multi-select has Acme Corporation selected, tenant rollout percentage and tenant tags to include in rollout inputs are empty](/docs/img/feature-toggles/included-tenants.png)

### Tenant rollout

Tenant rollout allows you to enable a flag for a pseudorandom percentage of all tenants.

The included tenants are determined using a MurmurHash of the tenant ID and a flag-specific key. This guarantees deterministic evaluation for any given tenant and flag combination, while ensuring that a different set of tenants is included for each flag.

![Screenshot of feature flag environment drawer, included tenants section expanded, tenants to include is empty, tenant rollout percentage is set to 50% and tenant tags to include in rollout multi-select has Tier/Free, Region/Australia, and Region/Europe selected](/docs/img/feature-toggles/tenant-rollout.png)

You can further restrict the rollout using tenant tags. For example, if you specify `Region/Australia`, `Region/Europe`, and `Tier/Enterprise`, a 50% rollout will only apply to 50% of Enterprise tenants in either Australia or Europe. If you do not specify any tenant tags, a 50% rollout will apply to 50% of all tenants.

As with excluded tenants, any changes to tenant tags apply immediately to feature flags.

## Client rollout

Client rollout allows you to enable a flag for a random percentage of your application users. The included users are determined using a MurmurHash of the [OpenFeature Targeting Key](https://openfeature.dev/docs/reference/concepts/evaluation-context#targeting-key) and a flag-specific key. This guarantees deterministic evaluation for any given user and flag combination.

To use client rollout, you must configure a targeting key in your OpenFeature client. Refer to the [OpenFeature SDK](https://openfeature.dev/docs/reference/sdks/) documentation for your development language for details on how to set the targeting key. If you do not set a targeting key, the feature flag will not be enabled for any users unless the rollout is set to 100%.

You should set the targeting key to a value that uniquely identifies your evaluation subject. For most applications, this will be a user identifier (such as a user ID), but you can use any identifier that suits your needs (for example, team, region, or server instance).

:::div{.warning}
Support for client rollout percentages was added in the following versions of the [provider libraries](/docs/feature-flags/providers):

- [.NET: `2.1.0`](https://github.com/OctopusDeploy/openfeature-provider-dotnet/releases/tag/v2.1.0)
- [Java: `0.3.0`](https://github.com/OctopusDeploy/openfeature-provider-java/releases/tag/0.3.0)
- [TypeScript/JavaScript: `3.0.0`](https://github.com/OctopusDeploy/openfeature-provider-ts-web/releases/tag/v3.0.0)

If you are not running the required minimum version of these libraries, the rollout percentage will be ignored (and handled as if the value was set to 100%).
:::

### Segments {#segments}

Segments allow you to further refine the client rollout for a flag based on data that is not modeled in Octopus. Segments are key/value pairs, and are supplied by your application via the [OpenFeature evaluation context](https://openfeature.dev/docs/reference/concepts/evaluation-context).

Like tenant targeting, segments are configured per-environment on the feature flag in Octopus.

![Screenshot of feature flag environment drawer, client rollout section expanded, client rollout percentage is set to 50% with 3 segments region/eu, region/au, and ring/early-adopter](/docs/img/feature-toggles/segments.png)

Refer to the [OpenFeature SDK](https://openfeature.dev/docs/reference/sdks/) documentation for your development language for more details on how to set these values.

Common segment examples include:

- Specific users (e.g. `user-id/123456`)
- Specific accounts (e.g. `account-id/123456`)
- License types (e.g. `license-type/free`)
- Geographic regions (e.g. `region/eu`)
- Rollout rings (e.g. `ring/early-adopter`)

A feature flag evaluation will match on segments if the evaluation context matches at least one segment for each key. If you specify `ring/early-adopter`, `region/eu`, and `region/au`, the rollout will apply only to users in the early-adopter ring who are in either the EU or AU regions. If you do not specify any segments, the rollout will apply to all users.

Some examples:

| Segments                                       | Evaluation Context                | Result |
|------------------------------------------------|-----------------------------------|--------|
| `user-id/123456`                               | `user-id/123456`                  | `On`   |
| `user-id/123456`                               | `user-id/789383`                  | `Off`  |
| `ring/early-adopter`, `region/eu`, `region/au` | `ring/early-adopter`, `region/eu` | `On`   |
| `ring/early-adopter`, `region/eu`, `region/au` | `ring/early-adopter`, `region/au` | `On`   |
| `ring/early-adopter`, `region/eu`, `region/au` | `license-type/free`               | `Off`  |
| `ring/early-adopter`, `region/eu`, `region/au` | `region/au`                       | `Off`  |

## Rollout groups {#rollout-groups}

By default, a percentage rollout on one feature flag will include a different set of tenants or clients than the same percentage rollout on another flag. This ensures the same tenants or clients are not always the first to receive every new feature.

Rollout groups let you connect rollout evaluation between multiple feature flags so that the same tenants or clients are included in the rollout across those flags. This can be useful when you have related features that should roll out to the same audience.

You can assign a rollout group to a feature flag from the feature flag page by selecting a group from the rollout group dropdown.

![Screenshot of feature flag page showing rollout group selector expanded with new onboarding flow group selected](/docs/img/feature-toggles/rollout-group-selector.png)

:::div{.warning}
If you have a tenant or client rollout configured, adding, changing, or removing a rollout group on a feature flag will change which tenants or clients are included in that rollout.
:::

### Managing rollout groups

You can manage rollout groups from the rollout groups page. To access this page, open the overflow menu on the feature flags list page and select **Manage Rollout Groups**.

![Screenshot of feature flag list page with overflow menu expanded highlighting the manage rollout groups button](/docs/img/feature-toggles/manage-rollout-group-overflow.png)

From the rollout groups page, you can add, rename, and delete rollout groups.

![Screenshot of rollout group list page with a single rollout group named new onboarding flow, used by the live chat and AI recommendations feature flags, with the overflow menu expanded and showing edit and delete options](/docs/img/feature-toggles/rollout-group-page.png)

You cannot delete a rollout group that is assigned to one or more feature flags. To delete a rollout group, first remove it from all feature flags that use it.