Fastly Compute@Edge

Use Upstash Redis SDK with Fastly Compute@Edge

The Upstash Redis SDK works seamlessly with Fastly Compute@Edge, allowing you to use Redis at the edge.

Installation

npm install @upstash/redis

Quick Start

1. Import from the Fastly-specific path

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

   Always use @upstash/redis/fastly when deploying to Fastly Compute@Edge.

2. Configure a backend in fastly.toml

   Create or update your fastly.toml file to define your Upstash Redis backend:

   # fastly.toml
   manifest_version = 2
   name = "your-app-name"
   description = "Your Fastly Compute@Edge app"
   authors = ["[e-mail]"]
   language = "javascript"
   
   [local_server.backends.upstash-db]
     url = "<UPSTASH_REDIS_REST_URL>"
   

   The backend name (e.g., upstash-db) must match the backend parameter in your Redis configuration.

3. Create a Redis instance

   const redis = new Redis({
     url: "<UPSTASH_REDIS_REST_URL>",
     token: "<UPSTASH_REDIS_REST_TOKEN>",
     backend: "upstash-db", // Must match the backend name in fastly.toml
   });
   
4. Use Redis in your handler

   addEventListener("fetch", (event) => event.respondWith(handleRequest(event)));
   
   async function handleRequest(_event) {
     try {
       const count = await redis.incr("fastly-counter");
       
       return new Response(JSON.stringify({ count }), {
         headers: { "Content-Type": "application/json" },
       });
     } catch (err) {
       return new Response(err.message, { status: 500 });
     }
   }
   

Configuration Options

The backend parameter is required for Fastly Compute@Edge and must match a backend defined in your fastly.toml file.

const redis = new Redis({
  // Required: Your Upstash Redis REST URL
  url: "<UPSTASH_REDIS_REST_URL>",
  
  // Required: Your Upstash Redis REST token
  token: "<UPSTASH_REDIS_REST_TOKEN>",
  
  // Required: Backend name from fastly.toml
  backend: "upstash-db",
  
  // Optional: Enable keep-alive connections
  keepAlive: true,
  
  // Optional: Read-your-writes consistency
  readYourWrites: true,
  
  // Optional: Automatic deserialization of JSON values
  automaticDeserialization: true,
  
  // Optional: Configure retry behavior
  retry: {
    retries: 3,
    backoff: (retryCount) => Math.exp(retryCount) * 50,
  },
  
  // Optional: Response encoding
  responseEncoding: "base64",
});

Complete Example

Project Structure

my-fastly-app/
├── src/
│   └── index.js
├── fastly.toml
├── package.json
└── webpack.config.js

fastly.toml

manifest_version = 2
name = "upstash-redis-fastly"
description = "Example of using Upstash with Fastly Compute@Edge"
authors = ["[e-mail]"]
language = "javascript"
service_id = "<SERVICE_ID>"

[local_server.backends.upstash-db]
  url = "<UPSTASH_REDIS_REST_URL>"

src/index.js

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

const redis = new Redis({
  url: "<UPSTASH_REDIS_REST_URL>",
  token: "<UPSTASH_REDIS_REST_TOKEN>",
  backend: "upstash-db",
});

addEventListener("fetch", (event) => event.respondWith(handleRequest(event)));

async function handleRequest(event) {
  try {
    const url = new URL(event.request.url);

    // Increment page view counter
    const views = await redis.incr(`views:${url.pathname}`);

    // Store visitor data
    await redis.lpush("recent-visits", {
      path: url.pathname,
      timestamp: Date.now(),
    });

    // Get recent visits
    const recentVisits = await redis.lrange("recent-visits", 0, 9);

    return new Response(
      JSON.stringify({
        path: url.pathname,
        views,
        recentVisits,
      }),
      {
        headers: { "Content-Type": "application/json" },
      }
    );
  } catch (err) {
    return new Response(err.message, { status: 500 });
  }
}

Backend Configuration

Fastly requires you to define backends for external services. Backends can be configured:

1. In fastly.toml (Local Development)

[local_server.backends.upstash-db]
  url = "<UPSTASH_REDIS_REST_URL>"

2. Via Fastly CLI

fastly backend create --name upstash-db --address your-redis-url.upstash.io

3. Via Fastly Web Interface

1. Go to your service in the Fastly web interface
2. Navigate to Origins > Hosts
3. Click Create a host
4. Set the name to match your backend parameter (e.g., upstash-db)
5. Set the address to your Upstash Redis URL

Environment Variables

Fastly Compute@Edge doesn’t have built-in environment variable support like other platforms. You have several options:

1. Use Fastly Config Stores (Recommended)

Config stores allow you to manage configuration separately from your code.

2. Use Fastly Edge Dictionaries

Edge dictionaries provide key-value storage for configuration.

3. Build-time Environment Variables

Use webpack or your bundler to inject values at build time:

// webpack.config.js
const webpack = require('webpack');

module.exports = {
  plugins: [
    new webpack.DefinePlugin({
      'process.env.UPSTASH_REDIS_REST_URL': JSON.stringify(process.env.UPSTASH_REDIS_REST_URL),
      'process.env.UPSTASH_REDIS_REST_TOKEN': JSON.stringify(process.env.UPSTASH_REDIS_REST_TOKEN),
    }),
  ],
};

Deployment

1. Build your application

   npm run build
   
2. Deploy to Fastly

   fastly compute publish
   

Telemetry

The SDK automatically reports "fastly" as the platform in telemetry data.

Telemetry cannot be disabled via environment variables in Fastly. Set enableAutoPipelining: false in the Redis constructor if needed.

Related

• Fastly Example - Complete example on GitHub
• Fastly Guide - Step-by-step tutorial
• Configuration - Complete configuration reference