feat: persist chat history

.github/workflows/migrate.yml

@@ -32,4 +32,4 @@ jobs:
         run: pnpm install --frozen-lockfile
 
       - name: Run migrations
-        run: pnpm run db:migrate
+        run: pnpm run db:migrate:all

.gitignore

@@ -28,3 +28,4 @@ pnpm-debug.log*
 *.db
 .vercel
 .env*.local
+next-env.d.ts

app/api/chat/route.ts

@@ -1,11 +1,83 @@
-import { streamText, UIMessage, convertToModelMessages } from 'ai';
+import {
+  streamText,
+  generateText,
+  UIMessage,
+  convertToModelMessages,
+} from 'ai';
+import { auth } from '@/lib/auth';
+import { getDbPool } from '@/lib/db';
+
+function uiMessageToText(message: UIMessage) {
+  const parts = message.parts ?? [];
+  const text = parts
+    .filter((p: any) => p?.type === 'text')
+    .map((p: any) => p.text)
+    .join('');
+  return text || (message as any).content || '';
+}
 
 export async function POST(req: Request) {
-  const { messages }: { messages: UIMessage[] } = await req.json();
+  const session = await auth.api.getSession({
+    headers: new Headers(req.headers),
+  });
+  if (!session?.user?.id) {
+    return new Response('unauthorized', { status: 401 });
+  }
+
+  const { messages, chatId }: { messages: UIMessage[]; chatId?: string } =
+    await req.json();
+
+  // Persist the latest user message (best-effort)
+  if (chatId && messages?.length) {
+    const last = messages[messages.length - 1];
+    if (last?.role === 'user') {
+      const pool = getDbPool();
+      await pool.query(
+        `insert into chat_messages (chat_id, role, content)
+         values ($1, $2, $3)`,
+        [chatId, 'user', uiMessageToText(last)]
+      );
+      await pool.query(`update chats set updated_at = now() where id = $1`, [
+        chatId,
+      ]);
+
+      // Auto-generate title if this is the first message
+      if (messages.length === 1) {
+        (async () => {
+          try {
+            const { text: title } = await generateText({
+              model: 'anthropic/claude-haiku-4.5',
+              system:
+                'You are a title generator. Create a concise, 3-5 word title for a chat based on the user message. Do not use quotes, bolding, or punctuation.',
+              prompt: uiMessageToText(last),
+            });
+            await pool.query('update chats set title = $1 where id = $2', [
+              title.trim().slice(0, 100) || 'New Chat',
+              chatId,
+            ]);
+          } catch (error) {
+            console.error('Title generation failed:', error);
+          }
+        })();
+      }
+    }
+  }
 
   const result = streamText({
     model: 'anthropic/claude-haiku-4.5',
     messages: await convertToModelMessages(messages),
+    onFinish: async ({ text }) => {
+      if (!chatId) return;
+      const pool = getDbPool();
+      await pool.query(
+        `insert into chat_messages (chat_id, role, content)
+         values ($1, $2, $3)`,
+        [chatId, 'assistant', text]
+      );
+      await pool.query(`update chats set updated_at = now() where id = $1`, [
+        chatId,
+      ]);
+    },
   });
 
   return result.toUIMessageStreamResponse();

app/api/chats/[chatId]/messages/route.ts

@@ -0,0 +1,45 @@
+import { NextResponse } from 'next/server';
+import { auth } from '@/lib/auth';
+import { getDbPool } from '@/lib/db';
+
+export async function POST(
+  req: Request,
+  { params }: { params: Promise<{ chatId: string }> }
+) {
+  const session = await auth.api.getSession({
+    headers: new Headers(req.headers),
+  });
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: 'unauthorized' }, { status: 401 });
+  }
+
+  const { chatId } = await params;
+  const body = (await req.json()) as { role: string; content: string };
+  const role = body.role;
+  const content = body.content;
+  if (!role || !content) {
+    return NextResponse.json({ error: 'bad_request' }, { status: 400 });
+  }
+
+  const pool = getDbPool();
+
+  // Ensure ownership
+  const chat = await pool.query(
+    `select id from chats where id = $1 and user_id = $2`,
+    [chatId, session.user.id]
+  );
+  if (chat.rowCount === 0) {
+    return NextResponse.json({ error: 'not_found' }, { status: 404 });
+  }
+
+  await pool.query(
+    `insert into chat_messages (chat_id, role, content)
+     values ($1, $2, $3)`,
+    [chatId, role, content]
+  );
+  await pool.query(`update chats set updated_at = now() where id = $1`, [
+    chatId,
+  ]);
+
+  return NextResponse.json({ ok: true });
+}

app/api/chats/[chatId]/route.ts

@@ -0,0 +1,63 @@
+import { NextResponse } from 'next/server';
+import { auth } from '@/lib/auth';
+import { getDbPool } from '@/lib/db';
+
+export async function GET(
+  req: Request,
+  { params }: { params: Promise<{ chatId: string }> }
+) {
+  const session = await auth.api.getSession({
+    headers: new Headers(req.headers),
+  });
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: 'unauthorized' }, { status: 401 });
+  }
+
+  const { chatId } = await params;
+  const pool = getDbPool();
+
+  // Ensure ownership
+  const chat = await pool.query(
+    `select id from chats where id = $1 and user_id = $2`,
+    [chatId, session.user.id]
+  );
+  if (chat.rowCount === 0) {
+    return NextResponse.json({ error: 'not_found' }, { status: 404 });
+  }
+
+  const { rows } = await pool.query(
+    `select id, role, content, created_at as "createdAt"
+     from chat_messages
+     where chat_id = $1
+     order by created_at asc`,
+    [chatId]
+  );
+
+  return NextResponse.json({ messages: rows });
+}
+
+export async function DELETE(
+  req: Request,
+  { params }: { params: Promise<{ chatId: string }> }
+) {
+  const session = await auth.api.getSession({
+    headers: new Headers(req.headers),
+  });
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: 'unauthorized' }, { status: 401 });
+  }
+
+  const { chatId } = await params;
+  const pool = getDbPool();
+
+  const res = await pool.query(
+    `delete from chats where id = $1 and user_id = $2`,
+    [chatId, session.user.id]
+  );
+
+  if (res.rowCount === 0) {
+    return NextResponse.json({ error: 'not_found' }, { status: 404 });
+  }
+
+  return NextResponse.json({ ok: true });
+}

app/api/chats/route.ts

@@ -0,0 +1,46 @@
+import { NextResponse } from 'next/server';
+import { auth } from '@/lib/auth';
+import { getDbPool } from '@/lib/db';
+
+export async function GET(req: Request) {
+  const session = await auth.api.getSession({
+    headers: new Headers(req.headers),
+  });
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: 'unauthorized' }, { status: 401 });
+  }
+
+  const pool = getDbPool();
+  const { rows } = await pool.query(
+    `select id, title, created_at as "createdAt", updated_at as "updatedAt"
+     from chats
+     where user_id = $1
+     order by updated_at desc
+     limit 50`,
+    [session.user.id]
+  );
+
+  return NextResponse.json({ chats: rows });
+}
+
+export async function POST(req: Request) {
+  const session = await auth.api.getSession({
+    headers: new Headers(req.headers),
+  });
+  if (!session?.user?.id) {
+    return NextResponse.json({ error: 'unauthorized' }, { status: 401 });
+  }
+
+  const body = (await req.json().catch(() => ({}))) as { title?: string };
+  const title = (body.title ?? 'New chat').slice(0, 200);
+
+  const pool = getDbPool();
+  const { rows } = await pool.query(
+    `insert into chats (user_id, title)
+     values ($1, $2)
+     returning id, title, created_at as "createdAt", updated_at as "updatedAt"`,
+    [session.user.id, title]
+  );
+
+  return NextResponse.json({ chat: rows[0] });
+}

app/global.css

@@ -1,5 +1,6 @@
 @import 'tailwindcss';
 @import 'tw-animate-css';
+@source '../node_modules/streamdown/dist/*.js';
 
 @custom-variant dark (&:is(.dark *));