diff --git a/app/[id]+api.ts b/app/[id]+api.ts
index 4a83d46..289f5ed 100644
--- a/app/[id]+api.ts
+++ b/app/[id]+api.ts
@@ -1,5 +1,5 @@
 import { deleteGuestInsecure, getGuestInsecure } from '../database/guests';
-import { Guest } from '../migrations/00000-createTableGuests';
+import { guestsSchema } from '../migrations/00000-createTableGuests';
 
 export async function GET(
   request: Request,
@@ -30,31 +30,15 @@ export async function PUT(
   request: Request,
   { id }: { id: string },
 ): Promise<Response> {
-  const body = await request.json();
-  const allowedKeys: Record<keyof Guest, boolean> = {
-    id: false,
-    firstName: true,
-    lastName: true,
-    attending: true,
-  };
-  const difference = Object.keys(body).filter(
-    (key) => !allowedKeys[key as keyof Guest],
-  );
+  const requestBody = await request.json();
 
-  if (difference.length > 0) {
+  const result = guestsSchema.safeParse(requestBody);
+
+  if (!result.success) {
     return Response.json(
       {
-        errors: [
-          {
-            message: `Request body contains more than allowed properties (${Object.keys(
-              allowedKeys,
-            ).join(
-              ', ',
-            )}). The request also contains these extra keys that are not allowed: ${difference.join(
-              ', ',
-            )}`,
-          },
-        ],
+        error: 'Request does not contain guest object',
+        errorIssues: result.error.issues,
       },
       {
         status: 400,
diff --git a/app/guests+api.ts b/app/guests+api.ts
index 53512df..f077342 100644
--- a/app/guests+api.ts
+++ b/app/guests+api.ts
@@ -1,4 +1,5 @@
 import { addGuestInsecure, getGuestsInsecure } from '../database/guests';
+import { guestsSchema } from '../migrations/00000-createTableGuests';
 
 export async function GET(request: Request): Promise<Response> {
   const cookie = request.headers.get('cookie');
@@ -16,20 +17,18 @@ export async function GET(request: Request): Promise<Response> {
 }
 
 export async function POST(request: Request): Promise<Response> {
-  const body = await request.json();
+  const requestBody = await request.json();
 
-  if (!body.firstName || !body.lastName) {
+  const result = guestsSchema.safeParse(requestBody);
+
+  console.log(result);
+
+  if (!result.success) {
     return Response.json(
-      'Request body missing a firstName or lastName property',
       {
-        status: 400,
+        error: 'Request does not contain guest object',
+        errorIssues: result.error.issues,
       },
-    );
-  }
-
-  if (Object.keys(body).length > 3) {
-    return Response.json(
-      'Request body contains more than firstName, lastName and deadline properties',
       {
         status: 400,
       },
@@ -37,12 +36,21 @@ export async function POST(request: Request): Promise<Response> {
   }
 
   const newGuest = {
-    firstName: body.firstName,
-    lastName: body.lastName,
+    firstName: result.data.firstName,
+    lastName: result.data.lastName,
     attending: false,
   };
 
   const guest = await addGuestInsecure(newGuest);
 
+  if (!guest) {
+    return Response.json(
+      { error: 'Guest not created' },
+      {
+        status: 500,
+      },
+    );
+  }
+
   return Response.json({ guest: guest });
 }
diff --git a/migrations/00000-createTableGuests.ts b/migrations/00000-createTableGuests.ts
index acf8806..b0574b5 100644
--- a/migrations/00000-createTableGuests.ts
+++ b/migrations/00000-createTableGuests.ts
@@ -1,4 +1,5 @@
 import { Sql } from 'postgres';
+import { z } from 'zod';
 
 export type Guest = {
   id: number;
@@ -7,6 +8,11 @@ export type Guest = {
   attending: boolean;
 };
 
+export const guestsSchema = z.object({
+  firstName: z.string().min(1).max(30),
+  lastName: z.string().min(1).max(30),
+});
+
 export async function up(sql: Sql) {
   await sql`
     CREATE TABLE guests (
diff --git a/package.json b/package.json
index 9c7ad58..c7d9b86 100644
--- a/package.json
+++ b/package.json
@@ -28,7 +28,8 @@
     "react-native": "0.74.2",
     "react-native-safe-area-context": "^4.10.5",
     "react-native-screens": "^3.32.0",
-    "tsx": "^4.12.0"
+    "tsx": "^4.12.0",
+    "zod": "^3.23.8"
   },
   "devDependencies": {
     "@babel/core": "^7.20.0",
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 9c95413..34019d4 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -59,6 +59,9 @@ importers:
       tsx:
         specifier: ^4.12.0
         version: 4.16.0
+      zod:
+        specifier: ^3.23.8
+        version: 3.23.8
     devDependencies:
       '@babel/core':
         specifier: ^7.20.0