---
displayed_sidebar: servicesSidebar
---

import ParameterTypes from "@site/src/components/ParameterTypes"

# FlagRouter

## Implements

- [IFlagRouter](../interfaces/IFlagRouter.mdx)

## Constructors

### constructor

`**new FlagRouter**(flags)`

#### Parameters

<ParameterTypes parameters={[
  {
    "name": "flags",
    "type": "`Record<string, boolean \\| Record&#60;string, boolean&#62;>`",
    "description": "",
    "optional": false,
    "defaultValue": "",
    "expandable": false,
    "children": []
  }
]} />

## Properties

<ParameterTypes parameters={[
  {
    "name": "flags",
    "type": "`any`",
    "description": "",
    "optional": false,
    "defaultValue": "",
    "expandable": false,
    "children": []
  }
]} />

## Methods

### isFeatureEnabled

`**isFeatureEnabled**(flag): boolean`

Check if a feature flag is enabled.
There are two ways of using this method:
1. `isFeatureEnabled("myFeatureFlag")`
2. `isFeatureEnabled({ myNestedFeatureFlag: "someNestedFlag" })`
We use 1. for top-level feature flags and 2. for nested feature flags. Almost all flags are top-level.
An example of a nested flag is workflows. To use it, you would do:
`isFeatureEnabled({ workflows: Workflows.CreateCart })`

#### Parameters

<ParameterTypes parameters={[
  {
    "name": "flag",
    "type": "`string` \\| `Record<string, string>`",
    "description": "The flag to check",
    "optional": false,
    "defaultValue": "",
    "expandable": false,
    "children": []
  }
]} />

#### Returns

`boolean`

<ParameterTypes parameters={[
  {
    "name": "boolean",
    "type": "`boolean`",
    "optional": true,
    "defaultValue": "",
    "description": "- Whether the flag is enabled or not",
    "expandable": false,
    "children": []
  }
]} />

___

### listFlags

`**listFlags**(): [FeatureFlagsResponse](../types/FeatureFlagsResponse.mdx)`

#### Returns

[FeatureFlagsResponse](../types/FeatureFlagsResponse.mdx)

<ParameterTypes parameters={[
  {
    "name": "FeatureFlagsResponse",
    "type": "`&#123; key: string ; value: boolean \\| Record&#60;string, boolean&#62;  &#125;`[]",
    "description": "",
    "optional": false,
    "defaultValue": "",
    "expandable": false,
    "children": []
  }
]} />

___

### setFlag

`**setFlag**(key, value): void`

Sets a feature flag.
Flags take two shapes:
`setFlag("myFeatureFlag", true)`
`setFlag("myFeatureFlag", { nestedFlag: true })`
These shapes are used for top-level and nested flags respectively, as explained in isFeatureEnabled.

#### Parameters

<ParameterTypes parameters={[
  {
    "name": "key",
    "type": "`string`",
    "description": "The key of the flag to set.",
    "optional": false,
    "defaultValue": "",
    "expandable": false,
    "children": []
  },
  {
    "name": "value",
    "type": "`boolean` \\| `&#123; [key: string]: boolean;  &#125;`",
    "description": "The value of the flag to set.",
    "optional": false,
    "defaultValue": "",
    "expandable": false,
    "children": []
  }
]} />

#### Returns

`void`

<ParameterTypes parameters={[
  {
    "name": "void",
    "type": "`void`",
    "optional": true,
    "defaultValue": "",
    "description": "- void",
    "expandable": false,
    "children": []
  }
]} />