diff --git a/bin/events.js b/bin/events.js
index c13c9a9..773724e 100644
--- a/bin/events.js
+++ b/bin/events.js
@@ -17,6 +17,7 @@ import { q } from '../src/db.js';
 const args = process.argv.slice(2);
 const cmd = args[0];
 const EMAIL_RE = /^[^@\s]+@[^@\s]+\.[^@\s]+$/;
+const ALLOWED_EVENT_TYPES = new Set(['login', 'timeline_view']);
 
 function help() {
   console.log('Usage:');
@@ -49,7 +50,13 @@ function metaCompact(m) {
 switch (cmd) {
   case 'list': {
     const type = parseFlag('--type');
-    const limit = Number(parseFlag('--limit') || 200);
+    if (type && !ALLOWED_EVENT_TYPES.has(type)) {
+      console.error(`unknown --type: ${type} (valid: ${[...ALLOWED_EVENT_TYPES].join(', ')})`);
+      process.exit(1);
+    }
+    const rawLimit = parseFlag('--limit');
+    const parsedLimit = rawLimit == null ? 200 : Number.parseInt(rawLimit, 10);
+    const limit = Number.isFinite(parsedLimit) && parsedLimit > 0 ? parsedLimit : 200;
     const rows = type
       ? q.listEventsByType.all(type, limit)
       : q.listEvents.all(limit);