diff --git a/src/endpoints.ts b/src/endpoints.ts
index dbd6212d7..9998fb622 100644
--- a/src/endpoints.ts
+++ b/src/endpoints.ts
@@ -257,7 +257,7 @@ export type Endpoints = {
 	'messaging/messages/read': { req: TODO; res: TODO; };
 
 	// meta
-	'meta': { req: { detail?: boolean; }; res: InstanceMetadata; };
+	'meta': { req: { detail?: boolean; }; res: InstanceMetadata; }; // TODO: 「detail が true なら DetailedInstanceMetadata を返す」のような型付けをしたい
 
 	// miauth
 	'miauth/gen-token': { req: TODO; res: TODO; };
diff --git a/src/entities.ts b/src/entities.ts
index ff2762a98..a8cbb28f5 100644
--- a/src/entities.ts
+++ b/src/entities.ts
@@ -154,7 +154,30 @@ export type MessagingMessage = {
 	groupId: string; // TODO
 };
 
-export type InstanceMetadata = {
+export type LiteInstanceMetadata = {
+	maintainerName: string | null;
+	maintainerEmail: string | null;
+	version: string;
+	name: string | null;
+	uri: string;
+	description: string | null;
+	tosUrl: string | null;
+	disableRegistration: boolean;
+	disableLocalTimeline: boolean;
+	disableGlobalTimeline: boolean;
+	driveCapacityPerLocalUserMb: number;
+	driveCapacityPerRemoteUserMb: number;
+	enableHcaptcha: boolean;
+	hcaptchaSiteKey: string | null;
+	enableRecaptcha: boolean;
+	recaptchaSiteKey: string | null;
+	swPublickey: string | null;
+	maxNoteTextLength: number;
+	enableEmail: boolean;
+	enableTwitterIntegration: boolean;
+	enableGithubIntegration: boolean;
+	enableDiscordIntegration: boolean;
+	enableServiceWorker: boolean;
 	emojis: {
 		id: string;
 		name: string;
@@ -171,6 +194,12 @@ export type InstanceMetadata = {
 	}[];
 };
 
+export type DetailedInstanceMetadata = LiteInstanceMetadata & {
+	features: Record<string, any>;
+};
+
+export type InstanceMetadata = LiteInstanceMetadata | DetailedInstanceMetadata;
+
 export type ServerInfo = {
 	machine: string;
 	cpu: {