diff --git a/src/lib/posts.ts b/src/lib/posts.ts
index 1c8e44a..2b346dd 100644
--- a/src/lib/posts.ts
+++ b/src/lib/posts.ts
@@ -76,3 +76,8 @@ export function listArchiveMonths(db: Database.Database): { month: string; count
 export function listByAuthor(db: Database.Database, authorId: number): Post[] {
   return db.prepare('SELECT * FROM posts WHERE author_id = ? ORDER BY updated_at DESC').all(authorId) as Post[];
 }
+
+export function canModifyPost(role: string, userId: number, post: { author_id: number | null }): boolean {
+  if (role === 'admin' || role === 'superuser') return true;
+  return post.author_id === userId;
+}
diff --git a/src/pages/api/admin/posts/[id].ts b/src/pages/api/admin/posts/[id].ts
index c7e8a33..8c7ef21 100644
--- a/src/pages/api/admin/posts/[id].ts
+++ b/src/pages/api/admin/posts/[id].ts
@@ -1,15 +1,17 @@
 import type { APIRoute } from 'astro';
 import { getDb } from '../../../../lib/db';
-import { getPostById, updatePost, deletePost } from '../../../../lib/posts';
+import { getPostById, updatePost, deletePost, canModifyPost } from '../../../../lib/posts';
 import { parsePostBody } from '../../../../lib/post-body';
 export const prerender = false;
 
 const json = (status: number, body: object) =>
   new Response(JSON.stringify(body), { status, headers: { 'Content-Type': 'application/json' } });
 
-export const PUT: APIRoute = async ({ params, request }) => {
+export const PUT: APIRoute = async ({ params, request, locals }) => {
   const id = Number(params.id);
-  if (!getPostById(getDb(), id)) return json(404, { error: 'Articolo non trovato.' });
+  const existing = getPostById(getDb(), id);
+  if (!existing) return json(404, { error: 'Articolo non trovato.' });
+  if (!canModifyPost(locals.user!.role, locals.user!.id, existing)) return json(403, { error: 'Non puoi modificare questo articolo.' });
   let data: Record<string, unknown>;
   try { data = await request.json(); } catch { return json(400, { error: 'Dati non validi.' }); }
   const parsed = parsePostBody(data);
@@ -23,7 +25,11 @@ export const PUT: APIRoute = async ({ params, request }) => {
   }
 };
 
-export const DELETE: APIRoute = ({ params }) => {
-  deletePost(getDb(), Number(params.id));
+export const DELETE: APIRoute = ({ params, locals }) => {
+  const id = Number(params.id);
+  const existing = getPostById(getDb(), id);
+  if (!existing) return json(404, { error: 'Articolo non trovato.' });
+  if (!canModifyPost(locals.user!.role, locals.user!.id, existing)) return json(403, { error: 'Non puoi eliminare questo articolo.' });
+  deletePost(getDb(), id);
   return json(200, { ok: true });
 };
diff --git a/src/pages/api/admin/posts/index.ts b/src/pages/api/admin/posts/index.ts
index 16305d7..6d95c5d 100644
--- a/src/pages/api/admin/posts/index.ts
+++ b/src/pages/api/admin/posts/index.ts
@@ -7,13 +7,13 @@ export const prerender = false;
 const json = (status: number, body: object) =>
   new Response(JSON.stringify(body), { status, headers: { 'Content-Type': 'application/json' } });
 
-export const POST: APIRoute = async ({ request }) => {
+export const POST: APIRoute = async ({ request, locals }) => {
   let data: Record<string, unknown>;
   try { data = await request.json(); } catch { return json(400, { error: 'Dati non validi.' }); }
   const parsed = parsePostBody(data);
   if ('error' in parsed) return json(400, { error: parsed.error });
   try {
-    const id = createPost(getDb(), parsed.value);
+    const id = createPost(getDb(), { ...parsed.value, author_id: locals.user!.id });
     return json(201, { id, slug: parsed.value.slug });
   } catch (err: any) {
     if (String(err?.message).includes('UNIQUE')) return json(400, { error: 'Slug già esistente.' });
diff --git a/tests/posts-ownership.test.ts b/tests/posts-ownership.test.ts
new file mode 100644
index 0000000..88f4a40
--- /dev/null
+++ b/tests/posts-ownership.test.ts
@@ -0,0 +1,21 @@
+import { describe, it, expect } from 'vitest';
+import { canModifyPost } from '../src/lib/posts';
+
+describe('canModifyPost', () => {
+  const own = { author_id: 7 };
+  const other = { author_id: 8 };
+  const orphan = { author_id: null };
+
+  it('admin e superuser modificano qualsiasi post', () => {
+    for (const role of ['admin', 'superuser']) {
+      expect(canModifyPost(role, 7, other)).toBe(true);
+      expect(canModifyPost(role, 7, orphan)).toBe(true);
+    }
+  });
+
+  it('user modifica solo i propri', () => {
+    expect(canModifyPost('user', 7, own)).toBe(true);
+    expect(canModifyPost('user', 7, other)).toBe(false);
+    expect(canModifyPost('user', 7, orphan)).toBe(false);
+  });
+});