Nano utility library for JavaScript to persist objects (POJOs) everywhere and with ease

Accessing localStorage and sessionStorage or writing to an in-memory object seems easy, but then there is browser private mode, there are security and quota restrictions, and if you try to run the same code on client (in the browser) and server, fun with Errors is guaranteed.

This is, why we've built this library that only has one job: Write an object into a storage backend, be able to read from it by key to get a value and also be able to delete data by key and make this possible isomorphic on client and server side, no matter what.

• ✅ Write to storage using simple key/value API
• ✅ Middleware function API allows to hook what is read and written
• ✅ Isomorphic, works in-browser and in Node.js
• ✅ Supports localStorage
• ✅ Supports sessionStorage
• ✅ Supports in-memory as an automatic fallback
• ✅ Supports Upstash (serverless, free-tier database backend)
• ✅ Just 571 byte nano sized (ESM, gizpped)
• ✅ Tree-shakable, side-effect free, so maybe just ~200 byte for you
• ✅ First class TypeScript support
• ✅ 100% Unit Test coverage

• yarn: yarn add simply-persist
• npm: npm install simply-persist

import { getStorage } from 'simply-persist'

const storage = getStorage('memory') // also: 'local' | 'session' | 'upstash'

// store a value
await storage.set('abc', 123)

// read a previously stored value, if not existing, return the default (0)
const valueStored = await storage.get('abc', 0)

// delete a single value
await storage.del('abc')

// delete all values
await storage.clear()

const { getStorage } = require('simply-persist')

// same API like ESM variant

The web storage APIs such as localStorage and sessionStorage are not available in Node.js. This library will gently fallback to the in-memory variant instead. Please mind the slightly different application behaviour in this case.