Installation

npm install @priolo/jon

Documentation

Examples

Complete Project

For LLM agents

You don't need to install anything: copy src/lib/store/rvx_juice.ts into the project as-is. It is a single self-contained file (react is the only dependency) exporting createStore and useStore.

A store is created from a "setup" object with 4 sections:

• state — initial state: plain object (deep-cloned) or a () => state factory
• mutators — the ONLY way to change state. Synchronous. Return a PARTIAL state object (shallow-merged into the current state); return undefined to skip the update.
• actions — sync/async side effects and orchestration. They don't return state: they call mutators through the injected store handle.
• getters — derived/computed values.

Every setup function receives (payload, store) — treat store like this: read store.state, call siblings as store.setX(...).

Rules (this is NOT redux/zustand — common mistakes):

• Call methods directly on the store, passing ONLY the payload: myStore.setCount(3).
• Never write store.state directly; only mutators replace state.
• useStore(store, fn?): fn(state, oldState) => boolean is a re-render PREDICATE, not a selector. useStore always returns the full state.

import { createStore, useStore } from "./rvx_juice"

const counterStore = createStore({
  state: { count: 0, label: "" },
  getters: {
    isEven: (_, store) => store.state.count % 2 == 0,
  },
  mutators: {
    setCount: (count) => ({ count }),      // partial: `label` is untouched
    setLabel: (label) => ({ label }),
  },
  actions: {
    fetchCount: async (url, store) => {
      const res = await fetch(url)
      store.setCount(await res.json())
    },
  },
})

function Counter() {
  const state = useStore(counterStore)
  return <button onClick={() => counterStore.setCount(state.count + 1)}>
    {state.count} — {counterStore.isEven() ? "even" : "odd"}
  </button>
}

Bonus: store actions/mutators are name(payload) => result, which maps 1:1 onto an LLM tool/function declaration — the agent and the UI can then mutate the same reactive state (see src/lib/experimentals/storeToAiTools.ts).

---

ROADMAP

• Documentation
• Involvement of the community
• Development of plugins to be applied to the library

DEVELOPMENT NOTE

If you use a local hard-link in package.json for testing
npm link <path_app>/node_modules/react
to avoid the "Invalid hook call" error
https://reactjs.org/warnings/invalid-hook-call-warning.html#duplicate-react

example:
npm link ||C:\Users\iorio\Documents\luca\zero\zero-os\web\||node_modules\react

this solution apparently does not work if you use VOLTA in that case you have to delete, in the JON project, inside node_modules the folders:

• react
• react-dom