diff --git a/netlify/functions/nip05.mjs b/netlify/functions/nip05.mjs
index 094f3cf..3629f59 100644
--- a/netlify/functions/nip05.mjs
+++ b/netlify/functions/nip05.mjs
@@ -112,6 +112,26 @@ function verifyAuth(header, action) {
   return { pubkey: ev.pubkey, name: normalizeName(tagVal(ev.tags, 'name')) };
 }
 
+// Best-effort in-memory throttle for the write endpoints. Serverless instances
+// are ephemeral, so this is a blunt abuse damper (mass name-squatting), not a
+// hard guarantee — the real gate is the signature on every claim.
+const WINDOW_MS = 60_000;
+const LIMIT = 12;
+const hits = new Map();
+
+function throttled(request) {
+  const ip =
+    request.headers.get('x-nf-client-connection-ip') ||
+    request.headers.get('x-forwarded-for') ||
+    'unknown';
+  const now = Date.now();
+  const recent = (hits.get(ip) ?? []).filter((t) => now - t < WINDOW_MS);
+  if (recent.length >= LIMIT) return true;
+  recent.push(now);
+  hits.set(ip, recent);
+  return false;
+}
+
 // ── Handlers ──────────────────────────────────────────────────────────────────
 
 /** GET /.well-known/nostr.json[?name=x] — the NIP-05 document itself. */
@@ -153,6 +173,7 @@ async function handleCheck(url) {
 
 /** POST /api/nip05/claim — reserve `name` for the signing pubkey. */
 async function handleClaim(request) {
+  if (throttled(request)) return json({ error: 'Too many requests.' }, 429);
   const auth = verifyAuth(request.headers.get('x-nip05-auth'), 'claim');
   if (!auth) return json({ error: 'Signature required.' }, 401);
   const { name, pubkey } = auth;
@@ -180,6 +201,7 @@ async function handleClaim(request) {
 
 /** POST /api/nip05/release — remove a name (its owner, or a platform owner). */
 async function handleRelease(request) {
+  if (throttled(request)) return json({ error: 'Too many requests.' }, 429);
   const auth = verifyAuth(request.headers.get('x-nip05-auth'), 'release');
   if (!auth) return json({ error: 'Signature required.' }, 401);
   const { name, pubkey } = auth;