senac-chat

TypeScript client for a classroom messaging exercise: each student builds a PWA, all apps share one Supabase project, and users identify themselves by phone number (WhatsApp-style, no OTP).

Install

yarn add senac-chat @supabase/supabase-js

Teacher setup (once)

1. Create one Supabase project for the class.
2. Run supabase/schema.sql in the SQL editor.
3. Enable Realtime for public.profiles and public.messages.
4. Share with students only:
   • project URL
   • anon key
     Never share the service-role key.

Student app usage

import { createSenacChat } from "senac-chat";

const chat = createSenacChat({
  url: import.meta.env.VITE_SUPABASE_URL,
  anonKey: import.meta.env.VITE_SUPABASE_ANON_KEY,
});

// First visit: register with phone as public ID
const me = await chat.register({
  phone: "11999990000",
  displayName: "Ana",
  appName: "AnaChat", // optional: name of this student's PWA
});
localStorage.setItem("senac-phone", me.phone);

// Next visits: restore session
// await chat.identify(localStorage.getItem("senac-phone")!);

const contacts = await chat.listContacts();

await chat.sendMessage({
  to: "11988880000", // classmate phone
  text: "Hello from my PWA!",
});

const thread = await chat.getHistory({ with: "11988880000" });

const unsubscribe = chat.onMessage((message) => {
  // Only messages where to_phone === my phone
  console.log(message.from_phone, message.text);
});

unsubscribe();

Data model

| Table | Role | |-------|------| | profiles | Registered users (phone PK, display_name, app_name) | | messages | Direct messages (from_phone → to_phone, text) |

Phones are normalized to digits only (11 99999-0000 → 11999990000).

Security note

This is intentionally open for a supervised classroom exercise (no Auth / no OTP). Anyone with the anon key can register any phone. Do not use this pattern for a real production messenger.

Scripts

yarn typecheck
yarn test
yarn build

API

| Method | Description | |--------|-------------| | createSenacChat(config) | Creates the client | | register({ phone, displayName, appName? }) | Registers / updates profile and starts session | | identify(phone) | Restores session for an existing phone | | getMe() | Current profile or null | | listContacts() | All registered classmates | | sendMessage({ to, text }) | Sends a direct message | | getHistory({ with?, limit? }) | Inbox or 1:1 thread | | onMessage(callback) | Live inbox for the current phone | | normalizePhone(phone) | Digits-only helper |