Start here

Three steps

1. 1

   Install

   terminalcopy

   npm install @sweidos/eidos
   # pnpm add @sweidos/eidos

2. 2

   Copy the helper file (Vite does this for you)

   Add the Vite plugin so eidos-sw.js lands in public/ on every build.

   vite.config.tscopy

   import { defineConfig } from 'vite'
   import { eidos } from '@sweidos/eidos/vite'
   
   export default defineConfig({
     plugins: [eidos()],
   })

   Not on Vite? Copy once: cp node_modules/@sweidos/eidos/dist/eidos-sw.js public/

3. 3

   Wrap once, then declare Save + Read

   main.tsxcopy

   import { createRoot } from 'react-dom/client'
   import { EidosProvider } from '@sweidos/eidos'
   import { App } from './App'
   
   createRoot(document.getElementById('root')!).render(
     <EidosProvider swPath="/eidos-sw.js">
       <App />
     </EidosProvider>,
   )

   src/lib/eidos.tscopy

   import { resource, action } from '@sweidos/eidos'
   import type { ActionContext } from '@sweidos/eidos'
   
   // Read — cache this GET when offline
   export const products = resource('/api/products', { offline: true })
   
   // Save — never lose this write; forward the ticket to your API
   export const createOrder = action(
     async (payload, ctx: ActionContext) => {
       const res = await fetch('/api/orders', {
         method: 'POST',
         headers: {
           'Content-Type': 'application/json',
           'Idempotency-Key': ctx.idempotencyKey,
         },
         body: JSON.stringify(payload),
       })
       return res.json()
     },
     { reliability: 'neverLose', name: 'createOrder' },
   )

   Keep resource / action at module scope so replay can find them after a reload.

Call it like a normal function

const result = await createOrder({ productId: 1, qty: 2 })

if ('queued' in result) {
  // Offline or flaky — already saved in the pocket. Will retry.
  showToast(result.message)
}

Try it without reading more

• Open the playground → Try it.
• Press sim offline in the header.
• Hit Save on an action — watch the queue keep it.
• Turn the network back on — it sends itself.