Cloudflare Workers & edge primitives

The model in one paragraph

A Worker is a fetch handler that runs at the edge. Everything else — R2, D1, KV, Queues, static assets, Durable Objects — is a binding declared in wrangler.jsonc and reached through env. If a resource is not bound, it is not reachable from your code. There is no connection string and no import of the bucket; you wire it in config, type it on Env, and call env.BINDING. Hold this picture and most "how do I access X" questions answer themselves: declare the binding, redeploy, use env.

Quick start

npm create cloudflare@latest (the C3 scaffolder) bootstraps a Worker or a full framework. Use it — it pins a correct compatibility_date and generates types.

npm create cloudflare@latest my-app          # plain Worker
npm create cloudflare@latest my-app -- --framework=react   # Vite + React SPA, GA plugin
cd my-app
npx wrangler dev          # local edge emulation at http://localhost:8787
npx wrangler deploy       # ships Worker + bound assets in one operation

Wrangler is v4 (an incremental release over the v3 rewrite — same config model, updated deps). Pin it: npx wrangler@4.