diff --git a/packages/backend/src/server/api/endpoints/antennas/markread.ts b/packages/backend/src/server/api/endpoints/antennas/markread.ts
new file mode 100644
index 0000000000..5ea3b0c600
--- /dev/null
+++ b/packages/backend/src/server/api/endpoints/antennas/markread.ts
@@ -0,0 +1,45 @@
+import define from '../../define.js';
+import { Antennas, AntennaNotes } from '@/models/index.js';
+import { FindOptionsWhere } from 'typeorm';
+import { AntennaNote } from '@/models/entities/antenna-note.js';
+
+export const meta = {
+	tags: ['antennas', 'account'],
+
+	requireCredential: true,
+
+	kind: 'write:account',
+
+} as const;
+
+export const paramDef = {
+	type: 'object',
+	properties: {
+		antennaId: { type: 'string', format: 'misskey:id' },
+	},
+	required: ['antennaId'],
+} as const;
+
+// eslint-disable-next-line import/no-default-export
+export default define(meta, paramDef, async (ps, me) => {
+	const antenna = await Antennas.findOneBy({
+		userId: me.id,
+		id: ps.antennaId,
+	});
+
+	if (!antenna) {
+		return null
+	}
+
+	await AntennaNotes.update({
+		antennaId: antenna.id,
+		read: false,
+	}, {
+		read: true,
+	})
+
+	return true
+
+});
+
+