# Source: https://upstash.com/docs/redis/howto/getstartedcloudflareworkers.md

> ## 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.

# Get Started with Cloudflare Workers

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.

See
[the code](https://github.com/upstash/examples/tree/master/examples/using-cloudflare-workers).

### 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.

### Step-1: Create Redis Database

Create a free Global database from
[Upstash Console](https://console.upstash.com). Find your REST URL and token in
the database details page in the console. Copy them.

Connect your database with redis-cli and add some greetings

```shell  theme={"system"}
usw1-selected-termite-30690.upstash.io:30690> set GB "Ey up?"
OK
usw1-selected-termite-30690.upstash.io:30690> set US "Yo, what’s up?"
OK
usw1-selected-termite-30690.upstash.io:30690> set TR "Naber dostum?"
OK
usw1-selected-termite-30690.upstash.io:30690> set DE "Was ist los?"
```

### Step-2: Edge Function

The best way to work with Cloudflare Workers is to use
[Wrangler](https://developers.cloudflare.com/workers/get-started/guide). After
installing and configuring wrangler, create a folder for your project inside the
folder run: `wrangler init`

Choose `yes` to create package.json, `no` to typescript and `yes` to create a
worker in src/index.js.

It will create `wrangler.toml`, `package.json` and `src/index.js`.

Append the Upstash REST URL and token to the toml as below:

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

# existing config

[vars]
UPSTASH_REDIS_REST_TOKEN = "AX_sASQgODM5ZjExZGEtMmI3Mi00Mjcwk3NDIxMmEwNmNkYjVmOGVmZTk5MzQ="
UPSTASH_REDIS_REST_URL = "https://us1-merry-macaque-31458.upstash.io/"
```

Install upstash-redis: `npm install @upstash/redis`

Replace `src/index.js` with the following:

```javascript  theme={"system"}
// src/index.js

import { Redis } from "@upstash/redis/cloudflare";

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

    const country = request.headers.get("cf-ipcountry");
    if (country) {
      const greeting = await redis.get(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 correct greeting for that location using the Redis
REST API.

## Run locally

Run `wrangler dev` and open your browser at
[localhost:8787](http://localhost:8787).

## Build and Deploy

Build and deploy your app to Cloudflare by running: `wrangler publish`

The url of your app will be logged:
[https://using-cloudflare-workers.upstash.workers.dev/](https://using-cloudflare-workers.upstash.workers.dev/)

## Typescript example

We also have a typescript example, available
[here](https://github.com/upstash/upstash-redis/tree/main/examples/cloudflare-workers-with-typescript).