implement AP fetch logs

11 files changed, 395 insertions, 95 deletions

diff --git a/packages/backend/migration/1738293576355-create_ap_fetch_log.js b/packages/backend/migration/1738293576355-create_ap_fetch_log.js
new file mode 100644
index 0000000000..4371f50b4a
--- /dev/null
+++ b/packages/backend/migration/1738293576355-create_ap_fetch_log.js
@@ -0,0 +1,19 @@
+export class CreateApFetchLog1738293576355 {
+	name = 'CreateApFetchLog1738293576355'
+
+	async up(queryRunner) {
+		await queryRunner.query(`CREATE TABLE "ap_fetch_log" ("id" character varying(32) NOT NULL, "at" TIMESTAMP WITH TIME ZONE NOT NULL, "duration" double precision, "host" text NOT NULL, "request_uri" text NOT NULL, "object_uri" text, "accepted" boolean, "result" text, "object" jsonb, "context_hash" text, CONSTRAINT "PK_ap_fetch_log" PRIMARY KEY ("id"))`);
+		await queryRunner.query(`CREATE INDEX "IDX_ap_fetch_log_at" ON "ap_fetch_log" ("at") `);
+		await queryRunner.query(`CREATE INDEX "IDX_ap_fetch_log_host" ON "ap_fetch_log" ("host") `);
+		await queryRunner.query(`CREATE INDEX "IDX_ap_fetch_log_object_uri" ON "ap_fetch_log" ("object_uri") `);
+		await queryRunner.query(`ALTER TABLE "ap_fetch_log" ADD CONSTRAINT "FK_ap_fetch_log_context_hash" FOREIGN KEY ("context_hash") REFERENCES "ap_context"("md5") ON DELETE CASCADE ON UPDATE NO ACTION`);
+	}
+
+	async down(queryRunner) {
+		await queryRunner.query(`ALTER TABLE "ap_fetch_log" DROP CONSTRAINT "FK_ap_fetch_log_context_hash"`);
+		await queryRunner.query(`DROP INDEX "public"."IDX_ap_fetch_log_object_uri"`);
+		await queryRunner.query(`DROP INDEX "public"."IDX_ap_fetch_log_host"`);
+		await queryRunner.query(`DROP INDEX "public"."IDX_ap_fetch_log_at"`);
+		await queryRunner.query(`DROP TABLE "ap_fetch_log"`);
+	}
+}
diff --git a/packages/backend/src/core/ApLogService.ts b/packages/backend/src/core/ApLogService.ts
new file mode 100644
index 0000000000..362eba24be
--- /dev/null
+++ b/packages/backend/src/core/ApLogService.ts
@@ -0,0 +1,189 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { createHash } from 'crypto';
+import { Inject, Injectable } from '@nestjs/common';
+import { LessThan } from 'typeorm';
+import { DI } from '@/di-symbols.js';
+import { SkApFetchLog, SkApInboxLog, SkApContext } from '@/models/_.js';
+import type { ApContextsRepository, ApFetchLogsRepository, ApInboxLogsRepository } from '@/models/_.js';
+import type { Config } from '@/config.js';
+import { JsonValue } from '@/misc/json-value.js';
+import { UtilityService } from '@/core/UtilityService.js';
+import { IdService } from '@/core/IdService.js';
+import { IActivity, IObject } from './activitypub/type.js';
+
+@Injectable()
+export class ApLogService {
+	constructor(
+		@Inject(DI.config)
+		private readonly config: Config,
+
+		@Inject(DI.apContextsRepository)
+		private apContextsRepository: ApContextsRepository,
+
+		@Inject(DI.apInboxLogsRepository)
+		private readonly apInboxLogsRepository: ApInboxLogsRepository,
+
+		@Inject(DI.apFetchLogsRepository)
+		private readonly apFetchLogsRepository: ApFetchLogsRepository,
+
+		private readonly utilityService: UtilityService,
+		private readonly idService: IdService,
+	) {}
+
+	/**
+	 * Creates an inbox log from an activity, and saves it if pre-save is enabled.
+	 */
+	public async createInboxLog(data: Partial<SkApInboxLog> & {
+		activity: IActivity,
+		keyId: string,
+	}): Promise<SkApInboxLog> {
+		const { object: activity, context, contextHash } = extractObjectContext(data.activity);
+		const host = this.utilityService.extractDbHost(data.keyId);
+
+		const log = new SkApInboxLog({
+			id: this.idService.gen(),
+			at: new Date(),
+			verified: false,
+			accepted: false,
+			host,
+			...data,
+			activity,
+			context,
+			contextHash,
+		});
+
+		if (this.config.activityLogging.preSave) {
+			await this.saveInboxLog(log);
+		}
+
+		return log;
+	}
+
+	/**
+	 * Saves or finalizes an inbox log.
+	 */
+	public async saveInboxLog(log: SkApInboxLog): Promise<SkApInboxLog> {
+		if (log.context) {
+			await this.saveContext(log.context);
+		}
+
+		// Will be UPDATE with preSave, and INSERT without.
+		await this.apInboxLogsRepository.upsert(log, ['id']);
+		return log;
+	}
+
+	/**
+	 * Creates a fetch log from an activity, and saves it if pre-save is enabled.
+	 */
+	public async createFetchLog(data: Partial<SkApFetchLog> & {
+		requestUri: string
+		host: string,
+	}): Promise<SkApFetchLog> {
+		const log = new SkApFetchLog({
+			id: this.idService.gen(),
+			at: new Date(),
+			accepted: false,
+			...data,
+		});
+
+		if (this.config.activityLogging.preSave) {
+			await this.saveFetchLog(log);
+		}
+
+		return log;
+	}
+
+	/**
+	 * Saves or finalizes a fetch log.
+	 */
+	public async saveFetchLog(log: SkApFetchLog): Promise<SkApFetchLog> {
+		if (log.context) {
+			await this.saveContext(log.context);
+		}
+
+		// Will be UPDATE with preSave, and INSERT without.
+		await this.apFetchLogsRepository.upsert(log, ['id']);
+		return log;
+	}
+
+	private async saveContext(context: SkApContext): Promise<void> {
+		// https://stackoverflow.com/a/47064558
+		await this.apContextsRepository
+			.createQueryBuilder('activity_context')
+			.insert()
+			.into(SkApContext)
+			.values(context)
+			.orIgnore('md5')
+			.execute();
+	}
+
+	/**
+	 * Deletes all expired AP logs and garbage-collects the AP context cache.
+	 * Returns the total number of deleted rows.
+	 */
+	public async deleteExpiredLogs(): Promise<number> {
+		// This is the date in UTC of the oldest log to KEEP
+		const oldestAllowed = new Date(Date.now() - this.config.activityLogging.maxAge);
+
+		// Delete all logs older than the threshold.
+		const inboxDeleted = await this.deleteExpiredInboxLogs(oldestAllowed);
+		const fetchDeleted = await this.deleteExpiredFetchLogs(oldestAllowed);
+
+		return inboxDeleted + fetchDeleted;
+	}
+
+	private async deleteExpiredInboxLogs(oldestAllowed: Date): Promise<number> {
+		const { affected } = await this.apInboxLogsRepository.delete({
+			at: LessThan(oldestAllowed),
+		});
+
+		return affected ?? 0;
+	}
+
+	private async deleteExpiredFetchLogs(oldestAllowed: Date): Promise<number> {
+		const { affected } = await this.apFetchLogsRepository.delete({
+			at: LessThan(oldestAllowed),
+		});
+
+		return affected ?? 0;
+	}
+}
+
+export function extractObjectContext<T extends IObject>(input: T) {
+	const object = Object.assign({}, input, { '@context': undefined }) as Omit<T, '@context'>;
+	const { context, contextHash } = parseContext(input['@context']);
+
+	return { object, context, contextHash };
+}
+
+export function parseContext(input: JsonValue | undefined): { contextHash: string | null, context: SkApContext | null } {
+	// Empty contexts are excluded for easier querying
+	if (input == null) {
+		return {
+			contextHash: null,
+			context: null,
+		};
+	}
+
+	const contextHash = createHash('md5').update(JSON.stringify(input)).digest('base64');
+	const context = new SkApContext({
+		md5: contextHash,
+		json: input,
+	});
+	return { contextHash, context };
+}
+
+export function calculateDurationSince(startTime: bigint): number {
+	// Calculate the processing time with correct rounding and decimals.
+	// 1. Truncate nanoseconds to microseconds
+	// 2. Scale to 1/10 millisecond ticks.
+	// 3. Round to nearest tick.
+	// 4. Sale to milliseconds
+	// Example: 123,456,789 ns -> 123,456 us -> 12,345.6 ticks -> 12,346 ticks -> 123.46 ms
+	const endTime = process.hrtime.bigint();
+	return Math.round(Number((endTime - startTime) / 1000n) / 10) / 100;
+}
diff --git a/packages/backend/src/core/CoreModule.ts b/packages/backend/src/core/CoreModule.ts
index 8c9f419c44..47be6967d7 100644
--- a/packages/backend/src/core/CoreModule.ts
+++ b/packages/backend/src/core/CoreModule.ts
@@ -157,6 +157,7 @@ import { QueueService } from './QueueService.js';
 import { LoggerService } from './LoggerService.js';
 import { SponsorsService } from './SponsorsService.js';
 import type { Provider } from '@nestjs/common';
+import { ApLogService } from '@/core/ApLogService.js';
 
 //#region 文字列ベースでのinjection用(循環参照対応のため)
 const $LoggerService: Provider = { provide: 'LoggerService', useExisting: LoggerService };
@@ -166,6 +167,7 @@ const $AccountMoveService: Provider = { provide: 'AccountMoveService', useExisti
 const $AccountUpdateService: Provider = { provide: 'AccountUpdateService', useExisting: AccountUpdateService };
 const $AnnouncementService: Provider = { provide: 'AnnouncementService', useExisting: AnnouncementService };
 const $AntennaService: Provider = { provide: 'AntennaService', useExisting: AntennaService };
+const $ApLogService: Provider = { provide: 'ApLogService', useExisting: ApLogService };
 const $AppLockService: Provider = { provide: 'AppLockService', useExisting: AppLockService };
 const $AchievementService: Provider = { provide: 'AchievementService', useExisting: AchievementService };
 const $AvatarDecorationService: Provider = { provide: 'AvatarDecorationService', useExisting: AvatarDecorationService };
@@ -322,6 +324,7 @@ const $SponsorsService: Provider = { provide: 'SponsorsService', useExisting: Sp
 		AccountUpdateService,
 		AnnouncementService,
 		AntennaService,
+		ApLogService,
 		AppLockService,
 		AchievementService,
 		AvatarDecorationService,
@@ -474,6 +477,7 @@ const $SponsorsService: Provider = { provide: 'SponsorsService', useExisting: Sp
 		$AccountUpdateService,
 		$AnnouncementService,
 		$AntennaService,
+		$ApLogService,
 		$AppLockService,
 		$AchievementService,
 		$AvatarDecorationService,
@@ -627,6 +631,7 @@ const $SponsorsService: Provider = { provide: 'SponsorsService', useExisting: Sp
 		AccountUpdateService,
 		AnnouncementService,
 		AntennaService,
+		ApLogService,
 		AppLockService,
 		AchievementService,
 		AvatarDecorationService,
@@ -778,6 +783,7 @@ const $SponsorsService: Provider = { provide: 'SponsorsService', useExisting: Sp
 		$AccountUpdateService,
 		$AnnouncementService,
 		$AntennaService,
+		$ApLogService,
 		$AppLockService,
 		$AchievementService,
 		$AvatarDecorationService,
diff --git a/packages/backend/src/core/activitypub/ApResolverService.ts b/packages/backend/src/core/activitypub/ApResolverService.ts
index a0c3a4846c..410803609c 100644
--- a/packages/backend/src/core/activitypub/ApResolverService.ts
+++ b/packages/backend/src/core/activitypub/ApResolverService.ts
@@ -7,7 +7,7 @@ import { Inject, Injectable } from '@nestjs/common';
 import { IsNull, Not } from 'typeorm';
 import type { MiLocalUser, MiRemoteUser } from '@/models/User.js';
 import { InstanceActorService } from '@/core/InstanceActorService.js';
-import type { NotesRepository, PollsRepository, NoteReactionsRepository, UsersRepository, FollowRequestsRepository, MiMeta } from '@/models/_.js';
+import type { NotesRepository, PollsRepository, NoteReactionsRepository, UsersRepository, FollowRequestsRepository, MiMeta, SkApFetchLog } from '@/models/_.js';
 import type { Config } from '@/config.js';
 import { HttpRequestService } from '@/core/HttpRequestService.js';
 import { DI } from '@/di-symbols.js';
@@ -17,7 +17,8 @@ import { LoggerService } from '@/core/LoggerService.js';
 import type Logger from '@/logger.js';
 import { fromTuple } from '@/misc/from-tuple.js';
 import { IdentifiableError } from '@/misc/identifiable-error.js';
-import { isCollectionOrOrderedCollection } from './type.js';
+import { ApLogService, calculateDurationSince, extractObjectContext } from '@/core/ApLogService.js';
+import { getNullableApId, isCollectionOrOrderedCollection } from './type.js';
 import { ApDbResolverService } from './ApDbResolverService.js';
 import { ApRendererService } from './ApRendererService.js';
 import { ApRequestService } from './ApRequestService.js';
@@ -43,6 +44,7 @@ export class Resolver {
 		private apRendererService: ApRendererService,
 		private apDbResolverService: ApDbResolverService,
 		private loggerService: LoggerService,
+		private readonly apLogService: ApLogService,
 		private recursionLimit = 256,
 	) {
 		this.history = new Set();
@@ -81,6 +83,44 @@ export class Resolver {
 			return value;
 		}
 
+		const host = this.utilityService.extractDbHost(value);
+		if (this.config.activityLogging.enabled && !this.utilityService.isSelfHost(host)) {
+			return await this._resolveLogged(value, host);
+		} else {
+			return await this._resolve(value, host);
+		}
+	}
+
+	private async _resolveLogged(requestUri: string, host: string): Promise<IObject> {
+		const startTime = process.hrtime.bigint();
+
+		const log = await this.apLogService.createFetchLog({
+			host: host,
+			requestUri,
+		});
+
+		try {
+			const result = await this._resolve(requestUri, host, log);
+
+			log.accepted = true;
+			log.result = 'ok';
+
+			return result;
+		} catch (err) {
+			log.accepted = false;
+			log.result = String(err);
+
+			throw err;
+		} finally {
+			log.duration = calculateDurationSince(startTime);
+
+			// Save or finalize asynchronously
+			this.apLogService.saveFetchLog(log)
+				.catch(err => this.logger.error('Failed to record AP object fetch:', err));
+		}
+	}
+
+	private async _resolve(value: string, host: string, log?: SkApFetchLog): Promise<IObject> {
 		if (value.includes('#')) {
 			// URLs with fragment parts cannot be resolved correctly because
 			// the fragment part does not get transmitted over HTTP(S).
@@ -98,7 +138,6 @@ export class Resolver {
 
 		this.history.add(value);
 
-		const host = this.utilityService.extractDbHost(value);
 		if (this.utilityService.isSelfHost(host)) {
 			return await this.resolveLocal(value);
 		}
@@ -115,6 +154,20 @@ export class Resolver {
 			? await this.apRequestService.signedGet(value, this.user) as IObject
 			: await this.httpRequestService.getActivityJson(value)) as IObject;
 
+		if (log) {
+			const { object: objectOnly, context, contextHash } = extractObjectContext(object);
+			const objectUri = getNullableApId(object);
+
+			if (objectUri) {
+				log.objectUri = objectUri;
+				log.host = this.utilityService.extractDbHost(objectUri);
+			}
+
+			log.object = objectOnly;
+			log.context = context;
+			log.contextHash = contextHash;
+		}
+
 		if (
 			Array.isArray(object['@context']) ?
 				!(object['@context'] as unknown[]).includes('https://www.w3.org/ns/activitystreams') :
@@ -232,6 +285,7 @@ export class ApResolverService {
 		private apRendererService: ApRendererService,
 		private apDbResolverService: ApDbResolverService,
 		private loggerService: LoggerService,
+		private readonly apLogService: ApLogService,
 	) {
 	}
 
@@ -252,6 +306,7 @@ export class ApResolverService {
 			this.apRendererService,
 			this.apDbResolverService,
 			this.loggerService,
+			this.apLogService,
 		);
 	}
 }
diff --git a/packages/backend/src/daemons/ApLogCleanupService.ts b/packages/backend/src/daemons/ApLogCleanupService.ts
index 261c6e3517..2b6693e19e 100644
--- a/packages/backend/src/daemons/ApLogCleanupService.ts
+++ b/packages/backend/src/daemons/ApLogCleanupService.ts
@@ -3,14 +3,11 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { Inject, Injectable, type OnApplicationShutdown } from '@nestjs/common';
-import { LessThan } from 'typeorm';
-import { DI } from '@/di-symbols.js';
-import type { Config } from '@/config.js';
+import { Injectable, type OnApplicationShutdown } from '@nestjs/common';
 import { bindThis } from '@/decorators.js';
-import type { ApInboxLogsRepository } from '@/models/_.js';
 import { LoggerService } from '@/core/LoggerService.js';
 import Logger from '@/logger.js';
+import { ApLogService } from '@/core/ApLogService.js';
 
 // 10 minutes
 export const scanInterval = 1000 * 60 * 10;
@@ -21,12 +18,7 @@ export class ApLogCleanupService implements OnApplicationShutdown {
 	private scanTimer: NodeJS.Timeout | null = null;
 
 	constructor(
-		@Inject(DI.config)
-		private readonly config: Config,
-
-		@Inject(DI.apInboxLogsRepository)
-		private readonly apInboxLogsRepository: ApInboxLogsRepository,
-
+		private readonly apLogService: ApLogService,
 		loggerService: LoggerService,
 	) {
 		this.logger = loggerService.getLogger('activity-log-cleanup');
@@ -47,15 +39,12 @@ export class ApLogCleanupService implements OnApplicationShutdown {
 
 	@bindThis
 	private async tick(): Promise<void> {
-		// This is the date in UTC of the oldest log to KEEP
-		const oldestAllowed = new Date(Date.now() - this.config.activityLogging.maxAge);
-
-		// Delete all logs older than the threshold.
-		const { affected } = await this.apInboxLogsRepository.delete({
-			at: LessThan(oldestAllowed),
-		});
-
-		this.logger.info(`Activity Log cleanup complete; removed ${affected ?? 0} expired logs.`);
+		try {
+			const affected = this.apLogService.deleteExpiredLogs();
+			this.logger.info(`Activity Log cleanup complete; removed ${affected} expired logs.`);
+		} catch (err) {
+			this.logger.error('Activity Log cleanup failed:', err as Error);
+		}
 	}
 
 	@bindThis
diff --git a/packages/backend/src/di-symbols.ts b/packages/backend/src/di-symbols.ts
index 6b53d38fb7..9f4ef5e2e9 100644
--- a/packages/backend/src/di-symbols.ts
+++ b/packages/backend/src/di-symbols.ts
@@ -23,6 +23,7 @@ export const DI = {
 	avatarDecorationsRepository: Symbol('avatarDecorationsRepository'),
 	latestNotesRepository: Symbol('latestNotesRepository'),
 	apContextsRepository: Symbol('apContextsRepository'),
+	apFetchLogsRepository: Symbol('apFetchLogsRepository'),
 	apInboxLogsRepository: Symbol('apInboxLogsRepository'),
 	noteFavoritesRepository: Symbol('noteFavoritesRepository'),
 	noteThreadMutingsRepository: Symbol('noteThreadMutingsRepository'),
diff --git a/packages/backend/src/models/RepositoryModule.ts b/packages/backend/src/models/RepositoryModule.ts
index dd4ba1c0e4..78510ba588 100644
--- a/packages/backend/src/models/RepositoryModule.ts
+++ b/packages/backend/src/models/RepositoryModule.ts
@@ -82,6 +82,7 @@ import {
 	MiWebhook,
 	NoteEdit,
 	SkApContext,
+	SkApFetchLog,
 	SkApInboxLog,
 } from './_.js';
 import type { DataSource } from 'typeorm';
@@ -134,6 +135,12 @@ const $apContextRepository: Provider = {
 	inject: [DI.db],
 };
 
+const $apFetchLogsRepository: Provider = {
+	provide: DI.apFetchLogsRepository,
+	useFactory: (db: DataSource) => db.getRepository(SkApFetchLog).extend(miRepository as MiRepository<SkApFetchLog>),
+	inject: [DI.db],
+};
+
 const $apInboxLogsRepository: Provider = {
 	provide: DI.apInboxLogsRepository,
 	useFactory: (db: DataSource) => db.getRepository(SkApInboxLog).extend(miRepository as MiRepository<SkApInboxLog>),
@@ -541,6 +548,7 @@ const $noteScheduleRepository: Provider = {
 		$avatarDecorationsRepository,
 		$latestNotesRepository,
 		$apContextRepository,
+		$apFetchLogsRepository,
 		$apInboxLogsRepository,
 		$noteFavoritesRepository,
 		$noteThreadMutingsRepository,
@@ -617,6 +625,7 @@ const $noteScheduleRepository: Provider = {
 		$avatarDecorationsRepository,
 		$latestNotesRepository,
 		$apContextRepository,
+		$apFetchLogsRepository,
 		$apInboxLogsRepository,
 		$noteFavoritesRepository,
 		$noteThreadMutingsRepository,
diff --git a/packages/backend/src/models/SkApFetchLog.ts b/packages/backend/src/models/SkApFetchLog.ts
new file mode 100644
index 0000000000..1e7d861b6c
--- /dev/null
+++ b/packages/backend/src/models/SkApFetchLog.ts
@@ -0,0 +1,89 @@
+/*
+ * SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
+ * SPDX-License-Identifier: AGPL-3.0-only
+ */
+
+import { Column, Index, JoinColumn, ManyToOne, PrimaryColumn, Entity } from 'typeorm';
+import { SkApContext } from '@/models/SkApContext.js';
+import { id } from './util/id.js';
+
+/**
+ * Records objects fetched via AP
+ */
+@Entity('ap_fetch_log')
+export class SkApFetchLog {
+	@PrimaryColumn({
+		...id(),
+		primaryKeyConstraintName: 'PK_ap_fetch_log',
+	})
+	public id: string;
+
+	@Index('IDX_ap_fetch_log_at')
+	@Column('timestamptz')
+	public at: Date;
+
+	/**
+	 * Processing duration in milliseconds
+	 */
+	@Column('double precision', { nullable: true })
+	public duration: number | null = null;
+
+	/**
+	 * DB hostname extracted from responseUri, or requestUri if fetch is incomplete
+	 */
+	@Index('IDX_ap_fetch_log_host')
+	@Column('text')
+	public host: string;
+
+	/**
+	 * Original requested URI
+	 */
+	@Column('text', {
+		name: 'request_uri',
+	})
+	public requestUri: string;
+
+	/**
+	 * Canonical URI / object ID, taken from the final payload
+	 */
+	@Column('text', {
+		name: 'object_uri',
+		nullable: true,
+	})
+	@Index('IDX_ap_fetch_log_object_uri')
+	public objectUri: string | null = null;
+
+	@Column('boolean', { nullable: true })
+	public accepted: boolean | null = null;
+
+	@Column('text', { nullable: true })
+	public result: string | null = null;
+
+	@Column('jsonb', { nullable: true })
+	// https://github.com/typeorm/typeorm/issues/8559
+	// eslint-disable-next-line @typescript-eslint/no-explicit-any
+	public object: any | null = null;
+
+	@Column({
+		type: 'text',
+		name: 'context_hash',
+		nullable: true,
+	})
+	public contextHash: string | null;
+
+	@ManyToOne(() => SkApContext, {
+		onDelete: 'CASCADE',
+		nullable: true,
+	})
+	@JoinColumn({
+		name: 'context_hash',
+		foreignKeyConstraintName: 'FK_ap_fetch_log_context_hash',
+	})
+	public context: SkApContext | null;
+
+	constructor(data?: Partial<SkApFetchLog>) {
+		if (data) {
+			Object.assign(this, data);
+		}
+	}
+}
diff --git a/packages/backend/src/models/_.ts b/packages/backend/src/models/_.ts
index dabcf89d2c..4bd6e78ef4 100644
--- a/packages/backend/src/models/_.ts
+++ b/packages/backend/src/models/_.ts
@@ -83,6 +83,7 @@ import { MiBubbleGameRecord } from '@/models/BubbleGameRecord.js';
 import { MiReversiGame } from '@/models/ReversiGame.js';
 import { MiNoteSchedule } from '@/models/NoteSchedule.js';
 import { SkApInboxLog } from '@/models/SkApInboxLog.js';
+import { SkApFetchLog } from '@/models/SkApFetchLog.js';
 import { SkApContext } from '@/models/SkApContext.js';
 import type { QueryDeepPartialEntity } from 'typeorm/query-builder/QueryPartialEntity.js';
 
@@ -132,6 +133,7 @@ export const miRepository = {
 export {
 	SkLatestNote,
 	SkApContext,
+	SkApFetchLog,
 	SkApInboxLog,
 	MiAbuseUserReport,
 	MiAbuseReportNotificationRecipient,
@@ -234,6 +236,7 @@ export type InstancesRepository = Repository<MiInstance> & MiRepository<MiInstan
 export type MetasRepository = Repository<MiMeta> & MiRepository<MiMeta>;
 export type LatestNotesRepository = Repository<SkLatestNote> & MiRepository<SkLatestNote>;
 export type ApContextsRepository = Repository<SkApContext> & MiRepository<SkApContext>;
+export type ApFetchLogsRepository = Repository<SkApFetchLog> & MiRepository<SkApFetchLog>;
 export type ApInboxLogsRepository = Repository<SkApInboxLog> & MiRepository<SkApInboxLog>;
 export type ModerationLogsRepository = Repository<MiModerationLog> & MiRepository<MiModerationLog>;
 export type MutingsRepository = Repository<MiMuting> & MiRepository<MiMuting>;
diff --git a/packages/backend/src/postgres.ts b/packages/backend/src/postgres.ts
index 9437ac936a..1a5fdc8412 100644
--- a/packages/backend/src/postgres.ts
+++ b/packages/backend/src/postgres.ts
@@ -86,6 +86,7 @@ import MisskeyLogger from '@/logger.js';
 import { bindThis } from '@/decorators.js';
 import { SkLatestNote } from '@/models/LatestNote.js';
 import { SkApContext } from '@/models/SkApContext.js';
+import { SkApFetchLog } from '@/models/SkApFetchLog.js';
 import { SkApInboxLog } from '@/models/SkApInboxLog.js';
 
 pg.types.setTypeParser(20, Number);
@@ -174,6 +175,7 @@ class MyCustomLogger implements Logger {
 export const entities = [
 	SkLatestNote,
 	SkApContext,
+	SkApFetchLog,
 	SkApInboxLog,
 	MiAnnouncement,
 	MiAnnouncementRead,
diff --git a/packages/backend/src/queue/processors/InboxProcessorService.ts b/packages/backend/src/queue/processors/InboxProcessorService.ts
index 4182f3e090..557a759136 100644
--- a/packages/backend/src/queue/processors/InboxProcessorService.ts
+++ b/packages/backend/src/queue/processors/InboxProcessorService.ts
@@ -4,7 +4,6 @@
  */
 
 import { URL } from 'node:url';
-import { createHash } from 'crypto';
 import { Inject, Injectable, OnApplicationShutdown } from '@nestjs/common';
 import httpSignature from '@peertube/http-signature';
 import * as Bull from 'bullmq';
@@ -30,11 +29,9 @@ import { CollapsedQueue } from '@/misc/collapsed-queue.js';
 import { MiNote } from '@/models/Note.js';
 import { MiMeta } from '@/models/Meta.js';
 import { DI } from '@/di-symbols.js';
-import { IdService } from '@/core/IdService.js';
-import { JsonValue } from '@/misc/json-value.js';
-import { SkApInboxLog, SkApContext } from '@/models/_.js';
-import type { ApInboxLogsRepository, ApContextsRepository } from '@/models/_.js';
+import { SkApInboxLog } from '@/models/_.js';
 import type { Config } from '@/config.js';
+import { ApLogService, calculateDurationSince } from '@/core/ApLogService.js';
 import { QueueLoggerService } from '../QueueLoggerService.js';
 import type { InboxJobData } from '../types.js';
 
@@ -66,13 +63,7 @@ export class InboxProcessorService implements OnApplicationShutdown {
 		private apRequestChart: ApRequestChart,
 		private federationChart: FederationChart,
 		private queueLoggerService: QueueLoggerService,
-		private idService: IdService,
-
-		@Inject(DI.apContextsRepository)
-		private apContextsRepository: ApContextsRepository,
-
-		@Inject(DI.apInboxLogsRepository)
-		private apInboxLogsRepository: ApInboxLogsRepository,
+		private readonly apLogService: ApLogService,
 	) {
 		this.logger = this.queueLoggerService.logger.createSubLogger('inbox');
 		this.updateInstanceQueue = new CollapsedQueue(process.env.NODE_ENV !== 'test' ? 60 * 1000 * 5 : 0, this.collapseUpdateInstanceJobs, this.performUpdateInstance);
@@ -89,14 +80,9 @@ export class InboxProcessorService implements OnApplicationShutdown {
 
 	private async _processLogged(job: Bull.Job<InboxJobData>): Promise<string> {
 		const startTime = process.hrtime.bigint();
-		const payload = job.data.activity;
+		const activity = job.data.activity;
 		const keyId = job.data.signature.keyId;
-		const log = this.createLog(payload, keyId);
-
-		// Pre-save the activity in case it leads to a hard-crash.
-		if (this.config.activityLogging.preSave) {
-			await this.recordLog(log);
-		}
+		const log = await this.apLogService.createInboxLog({ activity, keyId });
 
 		try {
 			const result = await this._process(job, log);
@@ -111,24 +97,18 @@ export class InboxProcessorService implements OnApplicationShutdown {
 
 			throw err;
 		} finally {
-			// Calculate the activity processing time with correct rounding and decimals.
-			// 1. Truncate nanoseconds to microseconds
-			// 2. Scale to 1/10 millisecond ticks.
-			// 3. Round to nearest tick.
-			// 4. Sale to milliseconds
-			// Example: 123,456,789 ns -> 123,456 us -> 12,345.6 ticks -> 12,346 ticks -> 123.46 ms
-			const endTime = process.hrtime.bigint();
-			const duration = Math.round(Number((endTime - startTime) / 1000n) / 10) / 100;
-			log.duration = duration;
+			const duration = log.duration = calculateDurationSince(startTime);
 
+			// TODO remove this
 			// Activities should time out after roughly 5 seconds.
 			// A runtime longer than 10 seconds could indicate a problem or attack.
 			if (duration > 10000) {
-				this.logger.warn(`Activity ${JSON.stringify(payload.id)} by "${keyId}" took ${(duration / 1000).toFixed(1)} seconds to complete`);
+				this.logger.warn(`Activity ${JSON.stringify(activity.id)} by "${keyId}" took ${(duration / 1000).toFixed(1)} seconds to complete`);
 			}
 
 			// Save or finalize asynchronously
-			this.recordLog(log).catch(err => this.logger.error('Failed to record AP activity:', err));
+			this.apLogService.saveInboxLog(log)
+				.catch(err => this.logger.error('Failed to record AP activity:', err));
 		}
 	}
 
@@ -368,46 +348,4 @@ export class InboxProcessorService implements OnApplicationShutdown {
 	async onApplicationShutdown(signal?: string) {
 		await this.dispose();
 	}
-
-	private createLog(payload: IActivity, keyId: string): SkApInboxLog {
-		const activity = Object.assign({}, payload, { '@context': undefined }) as unknown as JsonValue;
-		const host = this.utilityService.extractDbHost(keyId);
-
-		const log = new SkApInboxLog({
-			id: this.idService.gen(),
-			at: new Date(),
-			verified: false,
-			accepted: false,
-			activity,
-			keyId,
-			host,
-		});
-
-		const context = payload['@context'];
-		if (context) {
-			const md5 = createHash('md5').update(JSON.stringify(context)).digest('base64');
-			log.contextHash = md5;
-			log.context = new SkApContext({
-				md5,
-				json: context,
-			});
-		}
-
-		return log;
-	}
-
-	private async recordLog(log: SkApInboxLog): Promise<void> {
-		if (log.context) {
-			// https://stackoverflow.com/a/47064558
-			await this.apContextsRepository
-				.createQueryBuilder('activity_context')
-				.insert()
-				.into(SkApContext)
-				.values(log.context)
-				.orIgnore('md5')
-				.execute();
-		}
-
-		await this.apInboxLogsRepository.upsert(log, ['id']);
-	}
 }