---
description: Create your first Flagship feature flag and evaluate it inside a Cloudflare Worker using the binding API.
title: Get started
image: https://developers.cloudflare.com/og-docs.png
---

[Skip to content](#main-content)

> Documentation Index  
> Fetch the complete documentation index at: https://developers.cloudflare.com/flagship/llms.txt  
> Use this file to discover all available pages before exploring further.

# Get started

Last updated Aug 25, 2026|Copy as Markdown|[View as Markdown](https://4f1c5cd2.previews.developers.cloudflare.com/flagship/get-started/index.md)|[Agent setup](https://4f1c5cd2.previews.developers.cloudflare.com/agent-setup/)

In this guide, you will create a feature flag in Flagship and evaluate it inside a Cloudflare Worker.

## Create an app and a flag

In this example, you will create a boolean flag called `new-checkout` that controls whether users see a new checkout experience.

1. Log in to the [Cloudflare dashboard ↗](https://dash.cloudflare.com/) and select your account.
2. Go to **Compute** \> **Flagship**.
3. Select **Create app**. Give the app a name that matches your project or service (for example, `checkout-service`).
4. Inside the app, select **Create flag**.
5. Create a boolean flag with the key `new-checkout`. Optionally, add [targeting rules](https://4f1c5cd2.previews.developers.cloudflare.com/flagship/targeting/) to control who sees the flag.
6. Turn on the flag and select **Save**.

## Add the Flagship binding to your Worker

Add the Flagship binding in your Wrangler configuration file so your Worker can evaluate flags through a binding.

```jsonc
{
	"flagship": [
		{
			"binding": "FLAGS",
			"app_id": "<APP_ID>",
		},
	],
}
```

```toml
[[flagship]]
binding = "FLAGS"
app_id = "<APP_ID>"
```

Replace `<APP_ID>` with the app ID shown in the [Cloudflare dashboard ↗](https://dash.cloudflare.com/?to=/:account/flagship). The `binding` field sets the name you use to access Flagship in your Worker code. In this example, the binding is available as `env.FLAGS`.

After updating the Wrangler configuration, run `npx wrangler types` to generate TypeScript types for the binding.

## Evaluate the flag in your Worker

Use the `env.FLAGS` binding to evaluate the flag. The binding provides type-safe methods that return the flag value and fall back to the default you provide if evaluation fails.

```js
export default {
	async fetch(request, env) {
		const url = new URL(request.url);
		const userId = url.searchParams.get("userId") ?? "anonymous";

		const showNewCheckout = await env.FLAGS.getBooleanValue(
			"new-checkout",
			false,
			{ userId },
		);

		if (showNewCheckout) {
			return new Response("Welcome to the new checkout experience!");
		}

		return new Response("Standard checkout.");
	},
};
```

```ts
export default {
	async fetch(request: Request, env: Env): Promise<Response> {
		const url = new URL(request.url);
		const userId = url.searchParams.get("userId") ?? "anonymous";

		const showNewCheckout = await env.FLAGS.getBooleanValue(
			"new-checkout",
			false,
			{ userId },
		);

		if (showNewCheckout) {
			return new Response("Welcome to the new checkout experience!");
		}

		return new Response("Standard checkout.");
	},
};
```

The third argument to `getBooleanValue` is the [evaluation context](https://4f1c5cd2.previews.developers.cloudflare.com/flagship/concepts/#evaluation-context). Flagship uses the context attributes to match targeting rules. In this example, the `userId` attribute is passed so that percentage rollouts and user-specific targeting work correctly.

## Deploy and test

Deploy your Worker:

```sh
npx wrangler deploy
```

Test flag evaluation by sending a request:

```sh
curl "https://<YOUR_WORKER>.<YOUR_SUBDOMAIN>.workers.dev/?userId=user-42"
```

Change the flag value or targeting rules in the dashboard and observe the updated response. Flag changes propagate globally within seconds.

## (Optional) Use the OpenFeature SDK

If you prefer the [OpenFeature ↗](https://openfeature.dev/) standard interface, or if you are running outside of a Cloudflare Worker, you can use the [@cloudflare/flagship ↗](https://www.npmjs.com/package/@cloudflare/flagship) SDK instead of the binding.

Install the SDK:

npmyarnpnpmbun

```
npm i @cloudflare/flagship @openfeature/server-sdk
```

```
yarn add @cloudflare/flagship @openfeature/server-sdk
```

```
pnpm add @cloudflare/flagship @openfeature/server-sdk
```

```
bun add @cloudflare/flagship @openfeature/server-sdk
```

Evaluate flags using the OpenFeature client:

Pass the Flagship binding directly to the provider. This avoids additional HTTP overhead and is the recommended approach inside a Worker. The binding handles authentication automatically.

```js
import { OpenFeature } from "@openfeature/server-sdk";
import { FlagshipServerProvider } from "@cloudflare/flagship/server";

export default {
	async fetch(request, env) {
		await OpenFeature.setProviderAndWait(
			new FlagshipServerProvider({ binding: env.FLAGS }),
		);

		const client = OpenFeature.getClient();

		const showNewCheckout = await client.getBooleanValue(
			"new-checkout",
			false,
			{ targetingKey: "user-42" },
		);

		return new Response(
			showNewCheckout ? "New checkout!" : "Standard checkout.",
		);
	},
};
```

```ts
import { OpenFeature } from "@openfeature/server-sdk";
import { FlagshipServerProvider } from "@cloudflare/flagship/server";

export default {
	async fetch(request: Request, env: Env): Promise<Response> {
		await OpenFeature.setProviderAndWait(
			new FlagshipServerProvider({ binding: env.FLAGS }),
		);

		const client = OpenFeature.getClient();

		const showNewCheckout = await client.getBooleanValue(
			"new-checkout",
			false,
			{ targetingKey: "user-42" },
		);

		return new Response(
			showNewCheckout ? "New checkout!" : "Standard checkout.",
		);
	},
};
```

Use an app ID, account ID, and an API token when running outside of a Worker (for example, in Node.js). Generate an [API token](https://4f1c5cd2.previews.developers.cloudflare.com/fundamentals/api/get-started/create-token/) from your Cloudflare account with Flagship Evaluate permission.

```js
import { OpenFeature } from "@openfeature/server-sdk";
import { FlagshipServerProvider } from "@cloudflare/flagship/server";

await OpenFeature.setProviderAndWait(
	new FlagshipServerProvider({
		appId: "<APP_ID>",
		accountId: "<ACCOUNT_ID>",
		authToken: "<API_TOKEN>",
	}),
);

const client = OpenFeature.getClient();

const showNewCheckout = await client.getBooleanValue("new-checkout", false, {
	targetingKey: "user-42",
});
```

```ts
import { OpenFeature } from "@openfeature/server-sdk";
import { FlagshipServerProvider } from "@cloudflare/flagship/server";

await OpenFeature.setProviderAndWait(
	new FlagshipServerProvider({
		appId: "<APP_ID>",
		accountId: "<ACCOUNT_ID>",
		authToken: "<API_TOKEN>",
	}),
);

const client = OpenFeature.getClient();

const showNewCheckout = await client.getBooleanValue("new-checkout", false, {
	targetingKey: "user-42",
});
```

Refer to the [SDK documentation](https://4f1c5cd2.previews.developers.cloudflare.com/flagship/sdk/) for detailed setup instructions.

## Next steps

* Manage flags from the command line with the [wrangler flagship commands](https://4f1c5cd2.previews.developers.cloudflare.com/flagship/reference/wrangler-commands/).
* Learn about [targeting rules](https://4f1c5cd2.previews.developers.cloudflare.com/flagship/targeting/) to serve different values based on user attributes.
* Explore the full [binding API reference](https://4f1c5cd2.previews.developers.cloudflare.com/flagship/binding/) for all evaluation methods.
* Read about [percentage rollouts](https://4f1c5cd2.previews.developers.cloudflare.com/flagship/targeting/percentage-rollouts/) for gradual feature releases.
* Refer to the [Flagship API reference](https://4f1c5cd2.previews.developers.cloudflare.com/flagship/reference/api-reference/) to manage Flagship programmatically.

Was this helpful?

YesNo

## On this page

[![](https://4f1c5cd2.previews.developers.cloudflare.com/_astro/logo.te5VL_aD.svg)Docs](https://4f1c5cd2.previews.developers.cloudflare.com/)

```json
{"@context":"https://schema.org","@type":"TechArticle","@id":"https://developers.cloudflare.com/flagship/get-started/#page","headline":"Get started · Cloudflare Flagship docs","description":"Create your first Flagship feature flag and evaluate it inside a Cloudflare Worker using the binding API.","url":"https://developers.cloudflare.com/flagship/get-started/","inLanguage":"en","image":"https://developers.cloudflare.com/og-docs.png","dateModified":"2026-08-25","publisher":{"@type":"Organization","name":"Cloudflare","description":"One platform for your apps, agents, and workforce. Build, secure, and scale without managing infrastructure","url":"https://www.cloudflare.com/","sameAs":["https://github.com/cloudflare","https://www.linkedin.com/company/cloudflare","https://x.com/cloudflare"],"logo":{"@type":"ImageObject","url":"https://developers.cloudflare.com/logo.svg"},"address":{"@type":"PostalAddress","streetAddress":"101 Townsend St","addressLocality":"San Francisco","addressRegion":"CA","postalCode":"94107","addressCountry":"US"},"contactPoint":[{"@type":"ContactPoint","contactType":"Customer Support","url":"https://support.cloudflare.com/","availableLanguage":["English"]},{"@type":"ContactPoint","contactType":"Sales","url":"https://www.cloudflare.com/contact/","availableLanguage":["English"]}]},"isPartOf":{"@type":"WebSite","@id":"https://developers.cloudflare.com/#website","name":"Cloudflare Docs","url":"https://developers.cloudflare.com/"}}
```