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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.

GitHub Repository

You can find the project source code on GitHub.
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.

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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.

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Prerequisites

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

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Project Setup

Create a Cloudflare Worker with the following options: 
➜  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: 
cd greetings-cloudflare
npm install @upstash/redis

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Database Setup

Create a Redis database using Upstash Console or Upstash CLI and copy the UPSTASH_REDIS_REST_URL and UPSTASH_REDIS_REST_TOKEN into your wrangler.toml file.
wrangler.toml
# 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: CLI Tab

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Greetings Function Setup

Update src/index.ts:
src/index.ts
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.

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Run Locally

Run the following command to start your dev session: 
npx wrangler dev
Visit localhost:8787

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Build and Deploy

Build and deploy your app to Cloudflare: 
npx wrangler deploy
Visit the output url.