diff --git a/nextjs/app/api/party/[id]/join/route.ts b/nextjs/app/api/party/[id]/join/route.ts
new file mode 100644
index 0000000..0b9d0ca
--- /dev/null
+++ b/nextjs/app/api/party/[id]/join/route.ts
@@ -0,0 +1,43 @@
+import prisma from "@/lib/prisma";
+import { getServerSession } from "next-auth";
+
+export async function GET(_: Request, { params }: { params: { id: string } }) {
+  const session = await getServerSession();
+  if (!session || !session.user || !session.user.email) {
+    return Response.json(null, { status: 401 });
+  }
+
+  const party = await prisma.party.findUnique({
+    where: {
+      code: params.id,
+    },
+  });
+
+  if (!party) {
+    return Response.json(party, { status: 400 });
+  }
+
+  if (party.started) {
+    return Response.json(party, { status: 403 });
+  }
+
+  await prisma.user.update({
+    where: {
+      email: session.user.email,
+    },
+    data: {
+      partyId: party.id,
+    },
+  });
+
+  const res = await prisma.party.findUnique({
+    where: {
+      code: params.id,
+    },
+    include: {
+      players: true,
+    },
+  });
+
+  return Response.json(res);
+}
diff --git a/nextjs/app/api/party/join/[id]/route.ts b/nextjs/app/api/party/join/[id]/route.ts
deleted file mode 100644
index 630d89c..0000000
--- a/nextjs/app/api/party/join/[id]/route.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-import { getServerSession } from "next-auth";
-
-export async function GET(
-  req: Request,
-  { params }: { params: { id: string } },
-) {
-  const session = await getServerSession();
-  if (!session || !session.user) {
-    return Response.json(null, { status: 401 });
-  }
-
-  return Response.json(null);
-}
diff --git a/nextjs/app/api/party/route.ts b/nextjs/app/api/party/route.ts
index a7c2d74..2d123ea 100644
--- a/nextjs/app/api/party/route.ts
+++ b/nextjs/app/api/party/route.ts
@@ -30,17 +30,34 @@ export async function GET() {
 
 export async function POST() {
   const session = await getServerSession();
-  if (!session || !session.user) {
+  if (!session || !session.user || !session.user.email) {
     return Response.json(null, { status: 401 });
   }
 
-  const code = nanoid();
   const party = await prisma.party.create({
     data: {
-      code: code,
+      code: nanoid(),
       mode: Mode.CLASSIC,
     } as Party,
   });
 
-  return Response.json(party);
+  await prisma.user.update({
+    where: {
+      email: session.user.email,
+    },
+    data: {
+      partyId: party.id,
+    },
+  });
+
+  const res = await prisma.party.findUnique({
+    where: {
+      id: party.id,
+    },
+    include: {
+      players: true,
+    },
+  });
+
+  return Response.json(res);
 }