POC Cloudflare R2 API (Express)

Simple API to upload, download, and generate a preview link (signed URL) for images/files stored in Cloudflare R2.

Setup

• Install

pnpm install

• Create .env

This environment blocks dotfiles in the workspace, so copy env.example → .env on your machine:

cp env.example .env

Fill your real R2 values in .env.

Run

pnpm dev

Server: http://localhost:3000

Test script (uploads rac-01.jpg and prints signed URL)

In a separate terminal (with server running):

pnpm test:api

Optional:

API_BASE=http://localhost:3000 pnpm test:api

API

• Health

  • GET /health

• Upload (multipart)

  • POST /upload
  • form field: file
  • optional: ?key=my-file-name (without extension; extension inferred)

Example:

curl -F "file=@./my-image.jpg" "http://localhost:3000/upload"

• Download / inline preview
  • GET /download/*
  • Note: :key is the object key returned from upload (including any prefix).
  • Tip: If you set R2_PREFIX=uploads/, the returned key already includes uploads/... — you should pass it exactly as-is.

Example:

curl -L "http://localhost:3000/download/uploads/12345-abcd.jpg" --output out.jpg

• Get signed preview link
  • GET /preview/*
  • optional: ?expiresIn=3600

Example:

curl "http://localhost:3000/preview/uploads/12345-abcd.jpg"