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

# Use Redis in Cloudflare Workers

<Card title="GitHub Repository" icon="github" href="https://github.com/upstash/redis-js/tree/main/examples/cloudflare-workers-with-typescript" horizontal>
  You can find the project source code on GitHub.
</Card>

This tutorial showcases using Redis with REST API in Cloudflare Workers. We will
write a sample edge function (Cloudflare Workers) which will show a custom
greeting depending on the location of the client. We will load the greeting
message from Redis so you can update it without touching the code.

### Why Upstash?

* Cloudflare Workers does not allow TCP connections. Upstash provides REST API
  on top of the Redis database.
* Upstash is a serverless offering with per-request pricing which fits for edge
  and serverless functions.
* Upstash Global database provides low latency all over the world.

### Prerequisites

1. Install the Cloudflare Wrangler CLI with `npm install wrangler --save-dev`

### Project Setup

Create a Cloudflare Worker with the following options:

```shell theme={"system"}
➜  tutorials > ✗ npx wrangler init
╭ Create an application with Cloudflare Step 1 of 3
│
├ In which directory do you want to create your application?
│ dir ./greetings-cloudflare
│
├ What would you like to start with?
│ category Hello World example
│
├ Which template would you like to use?
│ type Hello World Worker
│
├ Which language do you want to use?
│ lang TypeScript
│
├ Copying template files
│ files copied to project directory
│
├ Updating name in `package.json`
│ updated `package.json`
│
├ Installing dependencies
│ installed via `npm install`
│
╰ Application created

╭ Configuring your application for Cloudflare Step 2 of 3
│
├ Installing @cloudflare/workers-types
│ installed via npm
│
├ Adding latest types to `tsconfig.json`
│ added @cloudflare/workers-types/2023-07-01
│
├ Retrieving current workerd compatibility date
│ compatibility date 2024-10-22
│
├ Do you want to use git for version control?
│ no git
│
╰ Application configured
```

Install Upstash Redis:

```shell theme={"system"}
cd greetings-cloudflare
npm install @upstash/redis
```

### Database Setup

Create a Redis database using [Upstash Console](https://console.upstash.com) or [Upstash CLI](https://github.com/upstash/cli) and copy the `UPSTASH_REDIS_REST_URL` and `UPSTASH_REDIS_REST_TOKEN` into your `wrangler.toml` file.

```toml wrangler.toml theme={"system"}
# existing config

[vars]
UPSTASH_REDIS_REST_URL = <YOUR_URL>
UPSTASH_REDIS_REST_TOKEN = <YOUR_TOKEN>
```

Using CLI Tab in the Upstash Console, add some greetings to your database:

<img src="https://mintlify.s3.us-west-1.amazonaws.com/upstash/redis/tutorials/img/examples/tutorial-cloudflare-workers.png" alt="CLI Tab" />

### Greetings Function Setup

Update `src/index.ts`:

```typescript src/index.ts theme={"system"}
import { Redis } from '@upstash/redis/cloudflare';

type RedisEnv = {
	UPSTASH_REDIS_REST_URL: string;
	UPSTASH_REDIS_REST_TOKEN: string;
};

export default {
	async fetch(request: Request, env: RedisEnv) {
		const redis = Redis.fromEnv(env);

		const country = request.headers.get('cf-ipcountry');
		if (country) {
			const greeting = await redis.get<string>(country);
			if (greeting) {
				return new Response(greeting);
			}
		}

		return new Response('Hello!');
	},
};
```

The code tries to find out the user's location checking the "cf-ipcountry"
header. Then it loads the corresponding greeting for that location using the Redis
REST API.

### Run Locally

Run the following command to start your dev session:

```shell theme={"system"}
npx wrangler dev
```

Visit [localhost:8787](http://localhost:8787)

### Build and Deploy

Build and deploy your app to Cloudflare:

```shell theme={"system"}
npx wrangler deploy
```

Visit the output url.