Build Cloudinary

KINDAreplaces $99/mosaves $1,188/yrback to the verdict

0%0 of 19 items done

Saved on this device only. Tick prerequisites first, then work the phases in order · do not start one until the checks above it pass.

An image CDN for your own sites without writing an image processor: originals in S3-compatible storage, imgproxy resizing and converting on request by signed URL, a cache in front, and a helper that emits srcset for every image. Video and the media library stay with the vendor.

estimated effort weekendthe files for this build are in the project pack

Processorimgproxy in DockerStorageCloudflare R2, Backblaze B2 or MinIOCacheCloudflare or CaddyUpload serviceA small Node endpoint

Before step 1

Everything below is assumed from the first step. Tick each one when you actually have it, not when you plan to.

installfree
Why Everything in this build runs on it: the server, the scripts, the tests.
Get it Download the LTS installer from nodejs.org, or install with your package manager (brew install node, or nvm install 22). Restart the terminal afterwards. open ↗
Verify node --version prints v22 or higher
installfree
Why Every step below is a command you type or a file you edit.
Get it VS Code (code.visualstudio.com), Cursor or Zed. Open a folder for the project and use the editor's built-in terminal. open ↗
Verify You can open a folder and run a command in its terminal
installfree
Why History for your code, and the way most hosts deploy.
Get it Install from git-scm.com or with your package manager, then run git init in the project folder once it exists. open ↗
Verify git --version prints a version
API keycents to a few dollars a month
Why Where originals live.
Get it Cloudflare R2: dashboard > R2 > Create bucket > Manage R2 API Tokens. Backblaze B2: Buckets > Create, then App Keys. Note endpoint, bucket, key id and secret. open ↗
installfree
Why imgproxy runs as a container.
Get it docs.docker.com/engine/install/ubuntu open ↗
Verify docker compose version prints
accountabout $5 a month
Why This needs one process running all the time with a public address. imgproxy needs a box; 2 GB of RAM is comfortable.
Get it Hetzner Cloud (from about 4 EUR), DigitalOcean or Fly.io. Ubuntu 24.04, the smallest size. You need SSH access and a public IP. Only needed for the deploy phase; develop locally first. open ↗
accountroughly $10 a year, or free on an existing domain
Why img.yourdomain.com
Get it Register at Cloudflare Registrar, Porkbun or Namecheap, or use a subdomain of one you already own. You add one DNS record in the deploy phase. open ↗
installfree
Why Automatic HTTPS in front of the Node process. Without TLS the browser features this relies on (and your visitors' trust) do not work.
Get it On the VPS: follow the install steps at caddyserver.com/docs/install for Ubuntu. One Caddyfile with your domain and a reverse_proxy line is the whole config. open ↗
Verify caddy version prints a version on the server
decidefree
Why Unsigned URLs would let anyone resize anything through your box.
Get it openssl rand -hex 32 twice, into .env.

Environment variables

These go in a .env file the app reads at startup. The pack's .env.example is this table as a file · copy it, never commit the filled-in version.

Variable	Needed	Example	Where the value comes from
`S3_ENDPOINT`	required	`https://<account>.r2.cloudflarestorage.com`	From the bucket provider.
`S3_BUCKET`	required	`images`	Bucket name.
`S3_ACCESS_KEY_ID`secret	required	`...`	Bucket access key.
`S3_SECRET_ACCESS_KEY`secret	required	`...`	Bucket secret.
`IMGPROXY_KEY`secret	required	`hex`	openssl rand -hex 32.
`IMGPROXY_SALT`secret	required	`hex`	openssl rand -hex 32.
`UPLOAD_TOKEN`secret	required	`base64`	Bearer token for the upload endpoint.
`IMG_URL`	required	`https://img.yourdomain.com`	Public base of the image domain.

The build, in order

1
Originals
Upload behind a token, content-hash keys, sniffed, capped, EXIF stripped, never overwritten.
1. terminal
  mkdir imgcdn && cd imgcdn && git init && npm init -y && npm pkg set type=module && npm install @aws-sdk/client-s3@3 sharp@0.35.3 mkdir -p data && cp .env.example .env
done when · tick each as it passes
next phase
2
Transforms
imgproxy with the bucket as source, signed URLs, auto WebP and AVIF.
1. Files docker-compose.yml
done when · tick each as it passes
next phase
3
Cache
Long cache headers, a cache in front, purge by key.
done when · tick each as it passes
next phase
4
Responsive helper
srcset and sizes for every image in your site.
done when · tick each as it passes
next phase
5
Operate
Lifecycle rules, memory limits, healthz, backups of the key index.
2. Files README.md
done when · tick each as it passes
next phase
6
Serve several sitesproduct builder
Per-site prefixes, tokens and metrics.
done when · tick each as it passes

what this build does not replace

Video, the media library, AI tagging, upload widgets: the $99.
video transcoding and adaptive streaming
the media library and AI tagging
global edge delivery you do not operate
upload widgets and SDKs for every platform

after v1, if you want it

Direct-to-bucket presigned uploads from the browser
Focal-point cropping metadata

Need the files? The project pack on the verdict page hands your agent the whole brief · more hosting.