Kinde · Const

Feature flags

Kinde feature flags control feature visibility or behavior for selected users, organizations, environments, or the whole application. They use typed values and can be inherited or overridden at supported scopes.

How it works

A Kinde feature flag is defined with a key, type, and value. Its value can be inherited from the business-level setting or overridden for an environment, organization, or user; the resolved flags are exposed in the signed-in user's access token under the feature_flags claim.

Returns

The signed-in user's resolved feature flags are provided in the access token as the custom feature_flags claim.

Key points

Use flags to control feature visibility or behavior for targeted audiences and environments.
Each flag combines a stable key with a declared type and value that application logic can consume.
Boolean flags are suitable for enabling or disabling a capability.
String flags can select text or other named configuration values.
Integer flags support whole-number configuration, not fractional values.
JSON flags represent structured key-value configuration.
Inherited values flow downward from the business setting unless a permitted override changes them.

Common mistakes

The flag's type and key cannot be changed after creation, so choose them carefully.
Deleting a feature flag cannot be undone.

Example: Read feature flags from an access token

const flags = accessToken.feature_flags ?? {};

const darkMode = flags.dark_mode?.v === true;
const checkoutVariant = flags.checkout_variant?.v ?? "control";

if (darkMode) {
  enableDarkMode();
}

renderCheckout(checkoutVariant);

Read the user's resolved feature flags from the access token and use each flag's value to control application behavior.

When to use it

Progressive rollout

Release a feature gradually to selected users or organizations before making it generally available.

Operational toggle

Switch a capability on or off without deploying a new application version.

Experiment configuration

Compare configuration or presentation variants using string or numeric values.

Structured configuration

Supply structured application settings through a JSON flag.

Interview questions

QWhat is a Kinde feature flag and why use one?

Feature flags let an application control access to features without changing the deployed code. A flag has a key, type, and value, and can be used for gradual rollout or temporary release control.

Follow-up: How can different users receive different values? Values cascade from the business level, with optional overrides at environment, organization, and user levels.

QWhich feature-flag types does Kinde provide?

Kinde supports boolean, string, integer, and JSON flags in the dashboard. Integers use whole numbers and are limited to -2147483648 through 2147483647.

Follow-up: Which types can the Management API create? It accepts string, integer, and boolean types; JSON flags must be created in the dashboard.

QHow does an application consume a user's Kinde feature flags?

After sign-in, the access token contains a custom feature_flags claim describing the user's flags. Application code can read the resolved value from that claim when deciding whether or how to expose functionality.

Follow-up: Where should a rollout override be applied? Choose the narrowest supported scope—environment, organization, or user—when only that audience should differ from the inherited value.

feature_flags
Boolean feature flags
String feature flags
Integer feature flags
JSON feature flags
Feature flag overrides
Kinde Management API

Source: About feature flags. Checked 2026-10-15.