diff --git a/src/models/repositories/note.ts b/src/models/repositories/note.ts
index 3ac490b001..03a50fecec 100644
--- a/src/models/repositories/note.ts
+++ b/src/models/repositories/note.ts
@@ -144,8 +144,8 @@ export class NoteRepository extends Repository<Note> {
 
 		let text = note.text;
 
-		if (note.name) {
-			text = `【${note.name}】\n${note.text}`;
+		if (note.name && note.uri) {
+			text = `【${note.name}】\n${(note.text || '').trim()}\n${note.uri}`;
 		}
 
 		const reactionEmojis = unique(concat([note.emojis, Object.keys(note.reactions)]));
diff --git a/src/remote/activitypub/kernel/announce/index.ts b/src/remote/activitypub/kernel/announce/index.ts
index ebd5a27b92..68fce52e17 100644
--- a/src/remote/activitypub/kernel/announce/index.ts
+++ b/src/remote/activitypub/kernel/announce/index.ts
@@ -1,13 +1,13 @@
 import Resolver from '../../resolver';
 import { IRemoteUser } from '../../../../models/entities/user';
 import announceNote from './note';
-import { IAnnounce, INote } from '../../type';
+import { IAnnounce, INote, validPost, getApId } from '../../type';
 import { apLogger } from '../../logger';
 
 const logger = apLogger;
 
 export default async (actor: IRemoteUser, activity: IAnnounce): Promise<void> => {
-	const uri = activity.id || activity;
+	const uri = getApId(activity);
 
 	logger.info(`Announce: ${uri}`);
 
@@ -22,15 +22,9 @@ export default async (actor: IRemoteUser, activity: IAnnounce): Promise<void> =>
 		throw e;
 	}
 
-	switch (object.type) {
-	case 'Note':
-	case 'Question':
-	case 'Article':
+	if (validPost.includes(object.type)) {
 		announceNote(resolver, actor, activity, object as INote);
-		break;
-
-	default:
+	} else {
 		logger.warn(`Unknown announce type: ${object.type}`);
-		break;
 	}
 };
diff --git a/src/remote/activitypub/kernel/announce/note.ts b/src/remote/activitypub/kernel/announce/note.ts
index 6843041475..2a07f50c8a 100644
--- a/src/remote/activitypub/kernel/announce/note.ts
+++ b/src/remote/activitypub/kernel/announce/note.ts
@@ -1,7 +1,7 @@
 import Resolver from '../../resolver';
 import post from '../../../../services/note/create';
 import { IRemoteUser, User } from '../../../../models/entities/user';
-import { IAnnounce, INote } from '../../type';
+import { IAnnounce, INote, getApId, getApIds } from '../../type';
 import { fetchNote, resolveNote } from '../../models/note';
 import { resolvePerson } from '../../models/person';
 import { apLogger } from '../../logger';
@@ -14,17 +14,13 @@ const logger = apLogger;
  * アナウンスアクティビティを捌きます
  */
 export default async function(resolver: Resolver, actor: IRemoteUser, activity: IAnnounce, note: INote): Promise<void> {
-	const uri = activity.id || activity;
+	const uri = getApId(activity);
 
 	// アナウンサーが凍結されていたらスキップ
 	if (actor.isSuspended) {
 		return;
 	}
 
-	if (typeof uri !== 'string') {
-		throw new Error('invalid announce');
-	}
-
 	// アナウンス先をブロックしてたら中断
 	const meta = await fetchMeta();
 	if (meta.blockedHosts.includes(extractDbHost(uri))) return;
@@ -52,11 +48,14 @@ export default async function(resolver: Resolver, actor: IRemoteUser, activity:
 	logger.info(`Creating the (Re)Note: ${uri}`);
 
 	//#region Visibility
-	const visibility = getVisibility(activity.to || [], activity.cc || [], actor);
+	const to = getApIds(activity.to);
+	const cc = getApIds(activity.cc);
+
+	const visibility = getVisibility(to, cc, actor);
 
 	let visibleUsers: User[] = [];
 	if (visibility == 'specified') {
-		visibleUsers = await Promise.all((note.to || []).map(uri => resolvePerson(uri)));
+		visibleUsers = await Promise.all(to.map(uri => resolvePerson(uri)));
 	}
 	//#endergion
 
diff --git a/src/remote/activitypub/kernel/create/image.ts b/src/remote/activitypub/kernel/create/image.ts
deleted file mode 100644
index 7720e8f1bd..0000000000
--- a/src/remote/activitypub/kernel/create/image.ts
+++ /dev/null
@@ -1,6 +0,0 @@
-import { IRemoteUser } from '../../../../models/entities/user';
-import { createImage } from '../../models/image';
-
-export default async function(actor: IRemoteUser, image: any): Promise<void> {
-	await createImage(image.url, actor);
-}
diff --git a/src/remote/activitypub/kernel/create/index.ts b/src/remote/activitypub/kernel/create/index.ts
index 0326b591f8..a6fa2336f3 100644
--- a/src/remote/activitypub/kernel/create/index.ts
+++ b/src/remote/activitypub/kernel/create/index.ts
@@ -1,14 +1,13 @@
 import Resolver from '../../resolver';
 import { IRemoteUser } from '../../../../models/entities/user';
-import createImage from './image';
 import createNote from './note';
-import { ICreate } from '../../type';
+import { ICreate, getApId, validPost } from '../../type';
 import { apLogger } from '../../logger';
 
 const logger = apLogger;
 
 export default async (actor: IRemoteUser, activity: ICreate): Promise<void> => {
-	const uri = activity.id || activity;
+	const uri = getApId(activity);
 
 	logger.info(`Create: ${uri}`);
 
@@ -23,19 +22,9 @@ export default async (actor: IRemoteUser, activity: ICreate): Promise<void> => {
 		throw e;
 	}
 
-	switch (object.type) {
-	case 'Image':
-		createImage(actor, object);
-		break;
-
-	case 'Note':
-	case 'Question':
-	case 'Article':
+	if (validPost.includes(object.type)) {
 		createNote(resolver, actor, object);
-		break;
-
-	default:
+	} else {
 		logger.warn(`Unknown type: ${object.type}`);
-		break;
 	}
 };
diff --git a/src/remote/activitypub/kernel/delete/index.ts b/src/remote/activitypub/kernel/delete/index.ts
index 199a6a6187..be7779e026 100644
--- a/src/remote/activitypub/kernel/delete/index.ts
+++ b/src/remote/activitypub/kernel/delete/index.ts
@@ -1,9 +1,8 @@
 import Resolver from '../../resolver';
 import deleteNote from './note';
 import { IRemoteUser } from '../../../../models/entities/user';
-import { IDelete } from '../../type';
+import { IDelete, getApId, validPost } from '../../type';
 import { apLogger } from '../../logger';
-import { Notes } from '../../../../models';
 
 /**
  * 削除アクティビティを捌きます
@@ -17,24 +16,11 @@ export default async (actor: IRemoteUser, activity: IDelete): Promise<void> => {
 
 	const object = await resolver.resolve(activity.object);
 
-	const uri = (object as any).id;
+	const uri = getApId(object);
 
-	switch (object.type) {
-		case 'Note':
-		case 'Question':
-		case 'Article':
-			deleteNote(actor, uri);
-			break;
-
-		case 'Tombstone':
-			const note = await Notes.findOne({ uri });
-			if (note != null) {
-				deleteNote(actor, uri);
-			}
-			break;
-
-		default:
-			apLogger.warn(`Unknown type: ${object.type}`);
-			break;
+	if (validPost.includes(object.type) || object.type === 'Tombstone') {
+		deleteNote(actor, uri);
+	} else {
+		apLogger.warn(`Unknown type: ${object.type}`);
 	}
 };
diff --git a/src/remote/activitypub/models/note.ts b/src/remote/activitypub/models/note.ts
index bb9465d90d..14425d7496 100644
--- a/src/remote/activitypub/models/note.ts
+++ b/src/remote/activitypub/models/note.ts
@@ -17,7 +17,7 @@ import { deliverQuestionUpdate } from '../../../services/note/polls/update';
 import { extractDbHost, toPuny } from '../../../misc/convert-host';
 import { Notes, Emojis, Polls } from '../../../models';
 import { Note } from '../../../models/entities/note';
-import { IObject, INote } from '../type';
+import { IObject, INote, getApIds, getOneApId, getApId, validPost } from '../type';
 import { Emoji } from '../../../models/entities/emoji';
 import { genId } from '../../../misc/gen-id';
 import { fetchMeta } from '../../../misc/fetch-meta';
@@ -32,7 +32,7 @@ export function validateNote(object: any, uri: string) {
 		return new Error('invalid Note: object is null');
 	}
 
-	if (!['Note', 'Question', 'Article'].includes(object.type)) {
+	if (!validPost.includes(object.type)) {
 		return new Error(`invalid Note: invalied object type ${object.type}`);
 	}
 
@@ -40,7 +40,7 @@ export function validateNote(object: any, uri: string) {
 		return new Error(`invalid Note: id has different host. expected: ${expectHost}, actual: ${extractDbHost(object.id)}`);
 	}
 
-	if (object.attributedTo && extractDbHost(object.attributedTo) !== expectHost) {
+	if (object.attributedTo && extractDbHost(getOneApId(object.attributedTo)) !== expectHost) {
 		return new Error(`invalid Note: attributedTo has different host. expected: ${expectHost}, actual: ${extractDbHost(object.attributedTo)}`);
 	}
 
@@ -53,8 +53,7 @@ export function validateNote(object: any, uri: string) {
  * Misskeyに対象のNoteが登録されていればそれを返します。
  */
 export async function fetchNote(value: string | IObject, resolver?: Resolver): Promise<Note | null> {
-	const uri = typeof value == 'string' ? value : value.id;
-	if (uri == null) throw new Error('missing uri');
+	const uri = getApId(value);
 
 	// URIがこのサーバーを指しているならデータベースからフェッチ
 	if (uri.startsWith(config.url + '/')) {
@@ -76,12 +75,12 @@ export async function fetchNote(value: string | IObject, resolver?: Resolver): P
 /**
  * Noteを作成します。
  */
-export async function createNote(value: any, resolver?: Resolver, silent = false): Promise<Note | null> {
+export async function createNote(value: string | IObject, resolver?: Resolver, silent = false): Promise<Note | null> {
 	if (resolver == null) resolver = new Resolver();
 
 	const object: any = await resolver.resolve(value);
 
-	const entryUri = value.id || value;
+	const entryUri = getApId(value);
 	const err = validateNote(object, entryUri);
 	if (err) {
 		logger.error(`${err.message}`, {
@@ -101,7 +100,7 @@ export async function createNote(value: any, resolver?: Resolver, silent = false
 	logger.info(`Creating the Note: ${note.id}`);
 
 	// 投稿者をフェッチ
-	const actor = await resolvePerson(note.attributedTo, resolver) as IRemoteUser;
+	const actor = await resolvePerson(getOneApId(note.attributedTo), resolver) as IRemoteUser;
 
 	// 投稿者が凍結されていたらスキップ
 	if (actor.isSuspended) {
@@ -109,24 +108,24 @@ export async function createNote(value: any, resolver?: Resolver, silent = false
 	}
 
 	//#region Visibility
-	note.to = note.to == null ? [] : typeof note.to == 'string' ? [note.to] : note.to;
-	note.cc = note.cc == null ? [] : typeof note.cc == 'string' ? [note.cc] : note.cc;
+	const to = getApIds(note.to);
+	const cc = getApIds(note.cc);
 
 	let visibility = 'public';
 	let visibleUsers: User[] = [];
-	if (!note.to.includes('https://www.w3.org/ns/activitystreams#Public')) {
-		if (note.cc.includes('https://www.w3.org/ns/activitystreams#Public')) {
+	if (!to.includes('https://www.w3.org/ns/activitystreams#Public')) {
+		if (cc.includes('https://www.w3.org/ns/activitystreams#Public')) {
 			visibility = 'home';
-		} else if (note.to.includes(`${actor.uri}/followers`)) {	// TODO: person.followerと照合するべき？
+		} else if (to.includes(`${actor.uri}/followers`)) {	// TODO: person.followerと照合するべき？
 			visibility = 'followers';
 		} else {
 			visibility = 'specified';
-			visibleUsers = await Promise.all(note.to.map(uri => resolvePerson(uri, resolver)));
+			visibleUsers = await Promise.all(to.map(uri => resolvePerson(uri, resolver)));
 		}
 	}
 	//#endergion
 
-	const apMentions = await extractMentionedUsers(actor, note.to, note.cc, resolver);
+	const apMentions = await extractMentionedUsers(actor, to, cc, resolver);
 
 	const apHashtags = await extractHashtags(note.tag);
 
@@ -217,11 +216,11 @@ export async function createNote(value: any, resolver?: Resolver, silent = false
 	const apEmojis = emojis.map(emoji => emoji.name);
 
 	const questionUri = note._misskey_question;
-	const poll = await extractPollFromQuestion(note._misskey_question || note).catch(() => undefined);
+	const poll = await extractPollFromQuestion(note._misskey_question || note, resolver).catch(() => undefined);
 
 	// ユーザーの情報が古かったらついでに更新しておく
 	if (actor.lastFetchedAt == null || Date.now() - actor.lastFetchedAt.getTime() > 1000 * 60 * 60 * 24) {
-		updatePerson(note.attributedTo);
+		if (actor.uri) updatePerson(actor.uri);
 	}
 
 	return await post(actor, {
diff --git a/src/remote/activitypub/models/question.ts b/src/remote/activitypub/models/question.ts
index 5c126c3a56..01086a7cf8 100644
--- a/src/remote/activitypub/models/question.ts
+++ b/src/remote/activitypub/models/question.ts
@@ -1,12 +1,19 @@
 import config from '../../../config';
 import Resolver from '../resolver';
-import { IQuestion } from '../type';
+import { IObject, IQuestion, isQuestion,  } from '../type';
 import { apLogger } from '../logger';
 import { Notes, Polls } from '../../../models';
 import { IPoll } from '../../../models/entities/poll';
 
-export async function extractPollFromQuestion(source: string | IQuestion): Promise<IPoll> {
-	const question = typeof source === 'string' ? await new Resolver().resolve(source) as IQuestion : source;
+export async function extractPollFromQuestion(source: string | IObject, resolver?: Resolver): Promise<IPoll> {
+	if (resolver == null) resolver = new Resolver();
+
+	const question = await resolver.resolve(source);
+
+	if (!isQuestion(question)) {
+		throw new Error('invalid type');
+	}
+
 	const multiple = !question.oneOf;
 	const expiresAt = question.endTime ? new Date(question.endTime) : null;
 
diff --git a/src/remote/activitypub/type.ts b/src/remote/activitypub/type.ts
index 95c69fb8ac..66163d39b0 100644
--- a/src/remote/activitypub/type.ts
+++ b/src/remote/activitypub/type.ts
@@ -6,9 +6,9 @@ export interface IObject {
 	id?: string;
 	summary?: string;
 	published?: string;
-	cc?: string[];
-	to?: string[];
-	attributedTo: string;
+	cc?: IObject | string | (IObject | string)[];
+	to?: IObject | string | (IObject | string)[];
+	attributedTo: IObject | string | (IObject | string)[];
 	attachment?: any[];
 	inReplyTo?: any;
 	replies?: ICollection;
@@ -23,6 +23,32 @@ export interface IObject {
 	sensitive?: boolean;
 }
 
+/**
+ * Get array of ActivityStreams Objects id
+ */
+export function getApIds(value: IObject | string | (IObject | string)[] | undefined): string[] {
+	if (value == null) return [];
+	const array = Array.isArray(value) ? value : [value];
+	return array.map(x => getApId(x));
+}
+
+/**
+ * Get first ActivityStreams Object id
+ */
+export function getOneApId(value: IObject | string | (IObject | string)[]): string {
+	const firstOne = Array.isArray(value) ? value[0] : value;
+	return getApId(firstOne);
+}
+
+/**
+ * Get ActivityStreams Object id
+ */
+export function getApId(value: string | IObject): string {
+	if (typeof value === 'string') return value;
+	if (typeof value.id === 'string') return value.id;
+	throw new Error(`cannot detemine id`);
+}
+
 export interface IActivity extends IObject {
 	//type: 'Activity';
 	actor: IObject | string;
@@ -42,8 +68,10 @@ export interface IOrderedCollection extends IObject {
 	orderedItems: IObject | string | IObject[] | string[];
 }
 
+export const validPost = ['Note', 'Question', 'Article', 'Audio', 'Document', 'Image', 'Page', 'Video'];
+
 export interface INote extends IObject {
-	type: 'Note' | 'Question';
+	type: 'Note' | 'Question' | 'Article' | 'Audio' | 'Document' | 'Image' | 'Page' | 'Video';
 	_misskey_content?: string;
 	_misskey_quote?: string;
 	_misskey_question?: string;
@@ -59,6 +87,9 @@ export interface IQuestion extends IObject {
 	endTime?: Date;
 }
 
+export const isQuestion = (object: IObject): object is IQuestion =>
+	object.type === 'Note' || object.type === 'Question';
+
 interface IQuestionChoice {
 	name?: string;
 	replies?: ICollection;
diff --git a/src/server/api/endpoints/ap/show.ts b/src/server/api/endpoints/ap/show.ts
index 9724a044b1..bbaa1fa109 100644
--- a/src/server/api/endpoints/ap/show.ts
+++ b/src/server/api/endpoints/ap/show.ts
@@ -10,7 +10,7 @@ import { Users, Notes } from '../../../../models';
 import { Note } from '../../../../models/entities/note';
 import { User } from '../../../../models/entities/user';
 import { fetchMeta } from '../../../../misc/fetch-meta';
-import { validActor } from '../../../../remote/activitypub/type';
+import { validActor, validPost } from '../../../../remote/activitypub/type';
 
 export const meta = {
 	tags: ['federation'],
@@ -145,7 +145,7 @@ async function fetchAny(uri: string) {
 		};
 	}
 
-	if (['Note', 'Question', 'Article'].includes(object.type)) {
+	if (validPost.includes(object.type)) {
 		const note = await createNote(object.id, undefined, true);
 		return {
 			type: 'Note',