Hono API Scaffolder
Add structured API routes to an existing Cloudflare Workers project. This skill runs AFTER the project shell exists (via cloudflare-worker-builder or vite-flare-starter) and produces route files, middleware, and endpoint documentation.
Workflow
Step 1: Gather Endpoints
Determine what the API needs. Either ask the user or infer from the project description. Group endpoints by resource:
Users: GET /api/users, GET /api/users/:id, POST /api/users, PUT /api/users/:id, DELETE /api/users/:id
Posts: GET /api/posts, GET /api/posts/:id, POST /api/posts, PUT /api/posts/:id
Auth: POST /api/auth/login, POST /api/auth/logout, GET /api/auth/me
Step 2: Create Route Files
One file per resource group. Use the template from assets/route-template.ts:
// src/routes/users.ts
import { Hono } from 'hono'
import { zValidator } from '@hono/zod-validator'
import { z } from 'zod'
import type { Env } from '../types'
const app = new Hono<{ Bindings: Env }>()
// GET /api/users
app.get('/', async (c) => {
const db = c.env.DB
const { results } = await db.prepare('SELECT * FROM users').all()
return c.json({ users: results })
})
// GET /api/users/:id
app.get('/:id', async (c) => {
const id = c.req.param('id')
const user = await db.prepare('SELECT * FROM users WHERE id = ?').bind(id).first()
if (!user) return c.json({ error: 'Not found' }, 404)
return c.json({ user })
})
// POST /api/users
const createUserSchema = z.object({
name: z.string().min(1),
email: z.string().email(),
})
app.post('/', zValidator('json', createUserSchema), async (c) => {
const body = c.req.valid('json')
// ... insert logic
return c.json({ user }, 201)
})
export default app
Step 3: Add Middleware
Based on project needs, add from assets/middleware-template.ts:
Auth middleware — protect routes requiring authentication:
import { createMiddleware } from 'hono/factory'
import type { Env } from '../types'
export const requireAuth = createMiddleware<{ Bindings: Env }>(async (c, next) => {
const token = c.req.header('Authorization')?.replace('Bearer ', '')
if (!token) return c.json({ error: 'Unauthorized' }, 401)
// Validate token...
await next()
})
CORS — use Hono's built-in:
import { cors } from 'hono/cors'
app.use('/api/*', cors({ origin: ['https://example.com'] }))
Step 4: Wire Routes
Mount all route groups in the main entry point:
// src/index.ts
import { Hono } from 'hono'
import type { Env } from './types'
import users from './routes/users'
import posts from './routes/posts'
import auth from './routes/auth'
import { errorHandler } from './middleware/error-handler'
const app = new Hono<{ Bindings: Env }>()
// Global error handler
app.onError(errorHandler)
// Mount routes
app.route('/api/users', users)
app.route('/api/posts', posts)
app.route('/api/auth', auth)
// Health check
app.get('/api/health', (c) => c.json({ status: 'ok' }))
export default app
Step 5: Create Types
// src/types.ts
export interface Env {
DB: D1Database
KV: KVNamespace // if needed
R2: R2Bucket // if needed
API_SECRET: string // secrets
}
Step 6: Generate API_ENDPOINTS.md
Document all endpoints. See references/endpoint-docs-template.md for the format:
## POST /api/users
Create a new user.
- **Auth**: Required (Bearer token)
- **Body**: `{ name: string, email: string }`
- **Response 201**: `{ user: User }`
- **Response 400**: `{ error: string, details: ZodError }`
Key Patterns
Zod Validation
Always validate request bodies with @hono/zod-validator:
import { zValidator } from '@hono/zod-validator'
app.post('/', zValidator('json', schema), async (c) => {
const body = c.req.valid('json') // fully typed
})
Install: pnpm add @hono/zod-validator zod
Error Handling
Use the standard error handler from assets/error-handler.ts:
export const errorHandler = (err: Error, c: Context) => {
console.error(err)
return c.json({ error: err.message }, 500)
}
API routes must return JSON errors, not redirects. fetch() follows redirects silently, then the client tries to parse HTML as JSON.
RPC Type Safety
For end-to-end type safety between Worker and client:
// Worker: export the app type
export type AppType = typeof app
// Client: use hc (Hono Client)
import { hc } from 'hono/client'
import type { AppType } from '../worker/src/index'
const client = hc<AppType>('https://api.example.com')
const res = await client.api.users.$get() // fully typed
Route Groups vs Single File
| Project size | Structure |
|---|
| < 10 endpoints | Single index.ts with all routes |
| 10-30 endpoints | Route files per resource (routes/users.ts) |
| 30+ endpoints | Route files + shared middleware + typed context |
Reference Files
Assets