Quickstart: Build Your First Blaze Worker in 5 Minutes

Build and deploy your first Cloudflare Worker with Blaze in under 5 minutes. Install the package, define routes, and export the fetch handler.

By the end of this guide you’ll have a running Cloudflare Worker that serves a JSON health-check endpoint and a typed D1 database route — deployed to Cloudflare’s global network. You’ll write the whole thing in TypeScript with full binding type safety from your first line of code.

1. Create a new Worker project

   Scaffold a new Cloudflare Workers project using the official create-cloudflare CLI, then move into the project directory.

   npm create cloudflare@latest my-worker
   cd my-worker
   

   When prompted, choose “Hello World” Worker and TypeScript. Skip Git initialisation if you prefer.

2. Install Blaze

   Add Blaze to your project with your preferred package manager.

   npm

   npm install blaze
   
3. Write your Worker

   Replace the contents of src/index.ts with the following. This example defines an Env type that mirrors your wrangler.toml bindings, creates a typed app, registers two routes, and exports the Cloudflare Workers fetch handler.

   src/index.ts

   import { createApp } from 'blaze'
   
   // Mirror your wrangler.toml bindings exactly —
   // this type flows to every req.env call in your app.
   type Env = {
     DB: D1Database
     KV: KVNamespace
   }
   
   const app = createApp<Env>()
   
   // Health-check endpoint
   app.get('/', (req, res) => {
     res.json({ status: 'ok', region: req.cf?.colo ?? 'unknown' })
   })
   
   // Typed D1 query — req.env.DB is fully type-safe
   app.get('/users/:id', async (req, res) => {
     const user = await req.env.DB
       .prepare('SELECT id, name, email FROM users WHERE id = ?')
       .bind(req.params.id)
       .first()
   
     if (!user) return res.status(404).json({ error: 'User not found' })
   
     res.json(user)
   })
   
   // Export the fetch handler for Cloudflare Workers
   export default {
     fetch: app.fetch,
   }
   
4. Add wrangler.toml bindings

   Open wrangler.toml and declare your D1 database binding. Replace your-database-id with the ID from npx wrangler d1 create myapp.

   wrangler.toml

   name = "my-worker"
   main = "src/index.ts"
   compatibility_date = "2024-09-23"
   
   [[d1_databases]]
   binding      = "DB"
   database_name = "myapp"
   database_id  = "your-database-id"
   

   The binding value here must match the key you used in your Env type (DB).

5. Run locally

   Start the local development server with hot-reload. Wrangler emulates the full Workers runtime including D1, KV, and other bindings.

   npx wrangler dev
   

   Visit http://localhost:8787 to see your health-check response, and http://localhost:8787/users/1 to test the D1 route.

6. Deploy

   When you’re ready to go live, deploy to Cloudflare’s global network with a single command.

   npx wrangler deploy
   

   Wrangler prints the deployed URL — your Worker is now live at the edge.

This quickstart covers the essentials to get you moving. For the full API — including sub-routers, middleware composition, error handling, and every req/res method — see the Core Concepts documentation.