Cloudflare Worker Builder
Scaffold a working Cloudflare Worker project from a brief description. Produces a deployable project with Hono routing, Vite dev server, and Static Assets.
Workflow
Step 1: Understand the Project
Ask about the project to choose the right bindings and structure:
- What does the app do? (API only, SPA + API, landing page)
- What data storage? (D1 database, R2 files, KV cache, none)
- Auth needed? (Clerk, better-auth, none)
- Custom domain or workers.dev subdomain?
A brief like "todo app with database" is enough to proceed.
Step 2: Scaffold the Project
npm create cloudflare@latest my-worker -- --type hello-world --ts --git --deploy false --framework none
cd my-worker
npm install hono
npm install -D @cloudflare/vite-plugin vite
Copy and customise the asset files from this skill's assets/ directory:
wrangler.jsonc — Worker configurationvite.config.ts — Vite + Cloudflare pluginsrc/index.ts — Hono app with Static Assets fallbackpackage.json — Scripts and dependenciestsconfig.json — TypeScript configpublic/index.html — SPA entry point
Step 3: Configure Bindings
Add bindings to wrangler.jsonc based on project needs. Wrangler 4.45+ auto-provisions resources on first deploy — always specify explicit names:
{
"name": "my-worker",
"main": "src/index.ts",
"compatibility_date": "2025-11-11",
"assets": {
"directory": "./public/",
"binding": "ASSETS",
"not_found_handling": "single-page-application",
"run_worker_first": ["/api/*"]
},
// Add as needed:
"d1_databases": [{ "binding": "DB", "database_name": "my-app-db" }],
"r2_buckets": [{ "binding": "STORAGE", "bucket_name": "my-app-files" }],
"kv_namespaces": [{ "binding": "CACHE", "title": "my-app-cache" }]
}
Step 4: Deploy
npm run dev # Local dev at http://localhost:8787
wrangler deploy # Production deploy
Critical Patterns
Export Syntax
// CORRECT — use this pattern
export default app
// WRONG — causes "Cannot read properties of undefined"
export default { fetch: app.fetch }
Source: honojs/hono #3955
Static Assets + API Routes
Without run_worker_first, SPA fallback intercepts API routes and returns index.html instead of JSON:
"assets": {
"not_found_handling": "single-page-application",
"run_worker_first": ["/api/*"] // CRITICAL
}
Source: workers-sdk #8879
Vite Config
import { defineConfig } from 'vite'
import { cloudflare } from '@cloudflare/vite-plugin'
export default defineConfig({ plugins: [cloudflare()] })
Always set the main field in wrangler.jsonc — the Vite plugin needs it.
Scheduled/Cron Handlers
When adding cron triggers, switch to explicit export:
export default {
fetch: app.fetch,
scheduled: async (event, env, ctx) => { /* ... */ }
}
Reference Files
Read these for detailed troubleshooting:
references/common-issues.md — 10 documented issues with sources and fixesreferences/architecture.md — Route priority, caching, Workers RPCreferences/deployment.md — CI/CD, auto-provisioning, gradual rollouts