feat: initialize Discord clone application with core backend services and Electron frontend.

Backend/routes/auth.js

@@ -147,7 +147,7 @@ router.post('/login/verify', async (req, res) => {
 
 router.get('/users/public-keys', async (req, res) => {
     try {
-        const result = await db.query('SELECT id, public_identity_key FROM users');
+        const result = await db.query('SELECT id, username, public_identity_key FROM users');
         res.json(result.rows);
     } catch (err) {
         console.error(err);

Backend/routes/channels.js

@@ -4,7 +4,7 @@ const db = require('../db');
 
 router.get('/', async (req, res) => {
     try {
-        const result = await db.query('SELECT * FROM channels ORDER BY name ASC');
+        const result = await db.query("SELECT * FROM channels WHERE type != 'dm' ORDER BY name ASC");
         res.json(result.rows);
     } catch (err) {
         console.error(err);

Backend/routes/dms.js

@@ -0,0 +1,79 @@
+const express = require('express');
+const router = express.Router();
+const db = require('../db');
+
+// POST /api/dms/open — Find-or-create a DM channel between two users
+router.post('/open', async (req, res) => {
+    const { userId, targetUserId } = req.body;
+
+    if (!userId || !targetUserId) {
+        return res.status(400).json({ error: 'userId and targetUserId required' });
+    }
+
+    if (userId === targetUserId) {
+        return res.status(400).json({ error: 'Cannot DM yourself' });
+    }
+
+    // Deterministic channel name so the same pair always maps to one channel
+    const sorted = [userId, targetUserId].sort();
+    const dmName = `dm-${sorted[0]}-${sorted[1]}`;
+
+    try {
+        // Check if DM channel already exists
+        const existing = await db.query(
+            'SELECT id FROM channels WHERE name = $1 AND type = $2',
+            [dmName, 'dm']
+        );
+
+        if (existing.rows.length > 0) {
+            return res.json({ channelId: existing.rows[0].id, created: false });
+        }
+
+        // Create the DM channel + participants in a transaction
+        await db.query('BEGIN');
+
+        const channelResult = await db.query(
+            'INSERT INTO channels (name, type) VALUES ($1, $2) RETURNING id',
+            [dmName, 'dm']
+        );
+        const channelId = channelResult.rows[0].id;
+
+        await db.query(
+            'INSERT INTO dm_participants (channel_id, user_id) VALUES ($1, $2), ($1, $3)',
+            [channelId, userId, targetUserId]
+        );
+
+        await db.query('COMMIT');
+
+        res.json({ channelId, created: true });
+    } catch (err) {
+        await db.query('ROLLBACK');
+        console.error('Error opening DM:', err);
+        res.status(500).json({ error: 'Server error' });
+    }
+});
+
+// GET /api/dms/user/:userId — List all DM channels for a user with the other user's info
+router.get('/user/:userId', async (req, res) => {
+    const { userId } = req.params;
+
+    try {
+        const result = await db.query(`
+            SELECT c.id AS channel_id, c.name AS channel_name, c.created_at,
+                   other_user.id AS other_user_id, other_user.username AS other_username
+            FROM dm_participants my
+            JOIN channels c ON c.id = my.channel_id AND c.type = 'dm'
+            JOIN dm_participants other ON other.channel_id = my.channel_id AND other.user_id != $1
+            JOIN users other_user ON other_user.id = other.user_id
+            WHERE my.user_id = $1
+            ORDER BY c.created_at DESC
+        `, [userId]);
+
+        res.json(result.rows);
+    } catch (err) {
+        console.error('Error fetching DM channels:', err);
+        res.status(500).json({ error: 'Server error' });
+    }
+});
+
+module.exports = router;

Backend/schema.sql

@@ -16,7 +16,7 @@ CREATE TABLE IF NOT EXISTS users (
 CREATE TABLE IF NOT EXISTS channels (
     id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
     name TEXT UNIQUE NOT NULL,
-    type TEXT DEFAULT 'text' CHECK (type IN ('text', 'voice')),
+    type TEXT DEFAULT 'text' CHECK (type IN ('text', 'voice', 'dm')),
     created_at TIMESTAMPTZ DEFAULT NOW()
 );
 
@@ -65,3 +65,9 @@ CREATE TABLE IF NOT EXISTS invites (
     key_version INTEGER NOT NULL,        -- Which key version is inside? (So we can invalidate leaks)
     created_at TIMESTAMPTZ DEFAULT NOW()
 );
+
+CREATE TABLE IF NOT EXISTS dm_participants (
+    channel_id UUID REFERENCES channels(id) ON DELETE CASCADE,
+    user_id UUID REFERENCES users(id) ON DELETE CASCADE,
+    PRIMARY KEY (channel_id, user_id)
+);

Backend/scripts/migrate_dms.js

@@ -0,0 +1,32 @@
+const path = require('path');
+require('dotenv').config({ path: path.join(__dirname, '../.env') });
+const db = require('../db');
+
+async function migrate() {
+    try {
+        console.log('Running DM migration...');
+
+        // 1. Update the check constraint to allow 'dm' type
+        await db.query("ALTER TABLE channels DROP CONSTRAINT IF EXISTS channels_type_check");
+        await db.query("ALTER TABLE channels ADD CONSTRAINT channels_type_check CHECK (type IN ('text', 'voice', 'dm'))");
+        console.log('  Updated channels type constraint to allow dm.');
+
+        // 2. Create dm_participants table
+        await db.query(`
+            CREATE TABLE IF NOT EXISTS dm_participants (
+                channel_id UUID REFERENCES channels(id) ON DELETE CASCADE,
+                user_id UUID REFERENCES users(id) ON DELETE CASCADE,
+                PRIMARY KEY (channel_id, user_id)
+            )
+        `);
+        console.log('  Created dm_participants table.');
+
+        console.log('DM migration complete.');
+        process.exit(0);
+    } catch (err) {
+        console.error('DM migration failed:', err);
+        process.exit(1);
+    }
+}
+
+migrate();

Backend/server.js

@@ -19,6 +19,7 @@ const channelRoutes = require('./routes/channels');
 const uploadRoutes = require('./routes/upload');
 const inviteRoutes = require('./routes/invites');
 const rolesRoutes = require('./routes/roles');
+const dmRoutes = require('./routes/dms');
 
 app.use(cors());
 app.use(express.json());
@@ -39,6 +40,7 @@ app.use('/api/upload', uploadRoutes);
 app.use('/api/invites', inviteRoutes);
 app.use('/api/invites', inviteRoutes);
 app.use('/api/roles', rolesRoutes);
+app.use('/api/dms', dmRoutes);
 app.use('/api/voice', require('./routes/voice'));
 
 app.get('/', (req, res) => {