One function.
Every protocol.

export const createInvoice = pikkuFunc({
  input: z.object({ orderId: z.string(), amount: z.number() }),
  output: InvoiceSchema,
  func: async ({ db, email }, { orderId, amount }) => {
    const invoice = await db.invoices.create({ orderId, amount })
    await email.send({ to: invoice.customer, template: 'invoice-created' })
    return invoice
  },
  permissions: { user: isAuthenticated },
})

wireHTTP({ method: 'post', route: '/invoices', func: createInvoice })
wireScheduler({ schedule: '0 9 * * 1', func: createInvoice })
wireQueueWorker({ queue: 'billing', func: createInvoice })
wireCLI({ program: 'billing', commands: { invoice: createInvoice } })
pikkuAIAgent({
  name: 'billing-assistant',
  tools: [createInvoice],
  model: 'anthropic/claude-sonnet-4-5',
})

// Fastify
import { pikkuFastify } from '@pikku/fastify'
const app = await pikkuFastify(pikku)
await app.listen({ port: 3000 })

// Or Lambda, Cloudflare Workers, Express, Next.js...
// Same Pikku project. Any runtime.