replit-hello-world

# Replit Hello World ## Overview Build a working Replit app that demonstrates core platform services: Express/Flask server, Replit Database (key-value store), Object Storage (file uploads), Auth (user login), and PostgreSQL. Produces a running app you can deploy. ## Prerequisites - Replit App created (template or blank) - `.replit` and `replit.nix` configured (see `replit-install-auth`) - Node.js 18+ or Python 3.10+ ## Instructions ### Step 1: Node.js — Express + Replit Database ```typescript // index.ts import express from 'express'; import Database from '@replit/database'; const app = express(); const db = new Database(); app.use(express.json()); // Health check with Replit env vars app.get('/health', (req, res) => { res.json({ status: 'ok', repl: process.env.REPL_SLUG, owner: process.env.REPL_OWNER, timestamp: new Date().toISOString(), }); }); // Replit Key-Value Database CRUD // Limits: 50 MiB total, 5,000 keys, 1 KB per key, 5 MiB per value app.post('/api/items', async (req, res) => { const { key, value } = req.body; await db.set(key, value); res.json({ stored: key }); }); app.get('/api/items/:key', async (req, res) => { const value = await db.get(req.params.key); if (value === null) return res.status(404).json({ error: 'Not found' }); res.json({ key: req.params.key, value }); }); app.get('/api/items', async (req, res) => { const prefix = (req.query.prefix as string) || ''; const keys = await db.list(prefix); res.json({ keys...