diff --git a/js/background.js b/js/background.js
index a69aae56a..297093796 100644
--- a/js/background.js
+++ b/js/background.js
@@ -204,7 +204,7 @@
 
       shutdown: async () => {
         // Stop background processing
-        window.Signal.AttachmentDownloads.stop();
+        window.libsession.Utils.AttachmentDownloads.stop();
 
         // Stop processing incoming messages
         if (messageReceiver) {
@@ -746,7 +746,7 @@
     if (messageReceiver) {
       await messageReceiver.close();
     }
-    window.Signal.AttachmentDownloads.stop();
+    window.libsession.Utils.AttachmentDownloads.stop();
   }
 
   let connectCount = 0;
@@ -801,7 +801,7 @@
     messageReceiver.addEventListener('configuration', onConfiguration);
     // messageReceiver.addEventListener('typing', onTyping);
 
-    window.Signal.AttachmentDownloads.start({
+    window.libsession.Utils.AttachmentDownloads.start({
       logger: window.log,
     });
 
diff --git a/js/modules/signal.js b/js/modules/signal.js
index 493ca8f68..8dc240578 100644
--- a/js/modules/signal.js
+++ b/js/modules/signal.js
@@ -9,7 +9,6 @@ const OS = require('../../ts/OS');
 const Settings = require('./settings');
 const Util = require('../../ts/util');
 const LinkPreviews = require('./link_previews');
-const AttachmentDownloads = require('./attachment_downloads');
 const { Message } = require('../../ts/components/conversation/Message');
 
 // Components
@@ -173,7 +172,6 @@ exports.setup = (options = {}) => {
   };
 
   return {
-    AttachmentDownloads,
     Components,
     Crypto,
     Data,
diff --git a/ts/receiver/attachments.ts b/ts/receiver/attachments.ts
index 8a97f95d3..43fbe9f97 100644
--- a/ts/receiver/attachments.ts
+++ b/ts/receiver/attachments.ts
@@ -3,7 +3,7 @@ import _ from 'lodash';
 import { MessageModel } from '../models/message';
 import { saveMessage } from '../../ts/data/data';
 import { fromBase64ToArrayBuffer } from '../session/utils/String';
-import { AttachmentUtils } from '../session/utils';
+import { AttachmentDownloads, AttachmentUtils } from '../session/utils';
 import { ConversationModel } from '../models/conversation';
 
 export async function downloadAttachment(attachment: any) {
@@ -168,7 +168,7 @@ async function processNormalAttachments(
   const isOpenGroupV2 = convo.isOpenGroupV2();
   const attachments = await Promise.all(
     normalAttachments.map((attachment: any, index: any) => {
-      return window.Signal.AttachmentDownloads.addJob(attachment, {
+      return AttachmentDownloads.addJob(attachment, {
         messageId: message.id,
         type: 'attachment',
         index,
@@ -193,7 +193,7 @@ async function processPreviews(message: MessageModel, convo: ConversationModel):
       }
       addedCount += 1;
 
-      const image = await window.Signal.AttachmentDownloads.addJob(item.image, {
+      const image = await AttachmentDownloads.addJob(item.image, {
         messageId: message.id,
         type: 'preview',
         index,
@@ -223,7 +223,7 @@ async function processAvatars(message: MessageModel, convo: ConversationModel):
 
       addedCount += 1;
 
-      const avatarJob = await window.Signal.AttachmentDownloads.addJob(item.avatar.avatar, {
+      const avatarJob = await AttachmentDownloads.addJob(item.avatar.avatar, {
         messaeId: message.id,
         type: 'contact',
         index,
@@ -268,7 +268,7 @@ async function processQuoteAttachments(
 
       addedCount += 1;
 
-      const thumbnail = await window.Signal.AttachmentDownloads.addJob(item.thumbnail, {
+      const thumbnail = await AttachmentDownloads.addJob(item.thumbnail, {
         messageId: message.id,
         type: 'quote',
         index,
@@ -297,7 +297,7 @@ async function processGroupAvatar(
 
   group = {
     ...group,
-    avatar: await window.Signal.AttachmentDownloads.addJob(group.avatar, {
+    avatar: await AttachmentDownloads.addJob(group.avatar, {
       messageId: message.id,
       type: 'group-avatar',
       index: 0,
diff --git a/js/modules/attachment_downloads.js b/ts/session/utils/AttachmentsDownload.ts
similarity index 78%
rename from js/modules/attachment_downloads.js
rename to ts/session/utils/AttachmentsDownload.ts
index a39c16daf..8139f0bf7 100644
--- a/js/modules/attachment_downloads.js
+++ b/ts/session/utils/AttachmentsDownload.ts
@@ -1,8 +1,7 @@
-/* global Signal, setTimeout, clearTimeout, getMessageController, NewReceiver */
-
-const { isNumber, omit } = require('lodash');
-const getGuid = require('uuid/v4');
-const {
+import { isNumber, omit } from 'lodash';
+// tslint:disable-next-line: no-submodule-imports
+import { default as getGuid } from 'uuid/v4';
+import {
   getMessageById,
   getNextAttachmentDownloadJobs,
   removeAttachmentDownloadJob,
@@ -10,33 +9,30 @@ const {
   saveAttachmentDownloadJob,
   saveMessage,
   setAttachmentDownloadJobPending,
-} = require('../../ts/data/data');
-
-module.exports = {
-  start,
-  stop,
-  addJob,
-};
+} from '../../../ts/data/data';
+import { MessageModel } from '../../models/message';
+import { downloadAttachment } from '../../receiver/attachments';
+import { MessageController } from '../messages';
 
 const MAX_ATTACHMENT_JOB_PARALLELISM = 3;
 
 const SECOND = 1000;
-const MINUTE = 60 * SECOND;
-const HOUR = 60 * MINUTE;
+const MINUTE = SECOND * 60;
+const HOUR = MINUTE * 60;
 const TICK_INTERVAL = MINUTE;
 
 const RETRY_BACKOFF = {
-  1: 30 * SECOND,
-  2: 30 * MINUTE,
-  3: 6 * HOUR,
+  1: SECOND * 30,
+  2: MINUTE * 30,
+  3: HOUR * 6,
 };
 
 let enabled = false;
-let timeout;
-let logger;
-const _activeAttachmentDownloadJobs = {};
+let timeout: any;
+let logger: any;
+const _activeAttachmentDownloadJobs: any = {};
 
-async function start(options = {}) {
+export async function start(options: any = {}) {
   ({ logger } = options);
   if (!logger) {
     throw new Error('attachment_downloads/start: logger must be provided!');
@@ -45,10 +41,10 @@ async function start(options = {}) {
   enabled = true;
   await resetAttachmentDownloadPending();
 
-  _tick();
+  void _tick();
 }
 
-async function stop() {
+export function stop() {
   enabled = false;
   if (timeout) {
     clearTimeout(timeout);
@@ -56,7 +52,7 @@ async function stop() {
   }
 }
 
-async function addJob(attachment, job = {}) {
+export async function addJob(attachment: any, job: any = {}) {
   if (!attachment) {
     throw new Error('attachments_download/addJob: attachment is required');
   }
@@ -85,7 +81,7 @@ async function addJob(attachment, job = {}) {
 
   await saveAttachmentDownloadJob(toSave);
 
-  _maybeStartJob();
+  void _maybeStartJob();
 
   return {
     ...attachment,
@@ -94,8 +90,9 @@ async function addJob(attachment, job = {}) {
   };
 }
 
+// tslint:disable: function-name
 async function _tick() {
-  _maybeStartJob();
+  await _maybeStartJob();
   timeout = setTimeout(_tick, TICK_INTERVAL);
 }
 
@@ -124,13 +121,14 @@ async function _maybeStartJob() {
   }
 
   const jobs = nextJobs.slice(0, Math.min(needed, nextJobs.length));
+  // tslint:disable: one-variable-per-declaration
   for (let i = 0, max = jobs.length; i < max; i += 1) {
     const job = jobs[i];
     _activeAttachmentDownloadJobs[job.id] = _runJob(job);
   }
 }
 
-async function _runJob(job) {
+async function _runJob(job: any) {
   const { id, messageId, attachment, type, index, attempts, isOpenGroupV2 } = job || {};
   let message;
 
@@ -145,7 +143,7 @@ async function _runJob(job) {
       await _finishJob(null, id);
       return;
     }
-    message = getMessageController().register(found.id, found);
+    message = MessageController.getInstance().register(found.id, found);
 
     const pending = true;
     await setAttachmentDownloadJobPending(id, pending);
@@ -153,7 +151,7 @@ async function _runJob(job) {
     let downloaded;
 
     try {
-      downloaded = await NewReceiver.downloadAttachment(attachment);
+      downloaded = await downloadAttachment(attachment);
     } catch (error) {
       // Attachments on the server expire after 60 days, then start returning 404
       if (error && error.code === 404) {
@@ -171,28 +169,29 @@ async function _runJob(job) {
       throw error;
     }
 
-    const upgradedAttachment = await Signal.Migrations.processNewAttachment(downloaded);
+    const upgradedAttachment = await window.Signal.Migrations.processNewAttachment(downloaded);
 
     await _addAttachmentToMessage(message, upgradedAttachment, { type, index });
 
     await _finishJob(message, id);
   } catch (error) {
-    const currentAttempt = (attempts || 0) + 1;
+    // tslint:disable: restrict-plus-operands
+    const currentAttempt: 1 | 2 | 3 = (attempts || 0) + 1;
 
     if (currentAttempt >= 3) {
       logger.error(
-        `_runJob: ${currentAttempt} failed attempts, marking attachment ${id} from message ${message.idForLogging()} as permament error:`,
+        `_runJob: ${currentAttempt} failed attempts, marking attachment ${id} from message ${message?.idForLogging()} as permament error:`,
         error && error.stack ? error.stack : error
       );
 
-      await _finishJob(message, id);
+      await _finishJob(message || null, id);
       await _addAttachmentToMessage(message, _markAttachmentAsError(attachment), { type, index });
 
       return;
     }
 
     logger.error(
-      `_runJob: Failed to download attachment type ${type} for message ${message.idForLogging()}, attempt ${currentAttempt}:`,
+      `_runJob: Failed to download attachment type ${type} for message ${message?.idForLogging()}, attempt ${currentAttempt}:`,
       error && error.stack ? error.stack : error
     );
 
@@ -204,37 +203,40 @@ async function _runJob(job) {
     };
 
     await saveAttachmentDownloadJob(failedJob);
+    // tslint:disable-next-line: no-dynamic-delete
     delete _activeAttachmentDownloadJobs[id];
-    _maybeStartJob();
+    void _maybeStartJob();
   }
 }
 
-async function _finishJob(message, id) {
+async function _finishJob(message: MessageModel | null, id: string) {
   if (message) {
     await saveMessage(message.attributes);
     const conversation = message.getConversation();
     if (conversation) {
-      message.commit();
+      await message.commit();
     }
   }
 
   await removeAttachmentDownloadJob(id);
+  // tslint:disable-next-line: no-dynamic-delete
   delete _activeAttachmentDownloadJobs[id];
-  _maybeStartJob();
+  await _maybeStartJob();
 }
 
 function getActiveJobCount() {
   return Object.keys(_activeAttachmentDownloadJobs).length;
 }
 
-function _markAttachmentAsError(attachment) {
+function _markAttachmentAsError(attachment: any) {
   return {
     ...omit(attachment, ['key', 'digest', 'id']),
     error: true,
   };
 }
 
-async function _addAttachmentToMessage(message, attachment, { type, index }) {
+// tslint:disable-next-line: cyclomatic-complexity
+async function _addAttachmentToMessage(message: any, attachment: any, { type, index }: any) {
   if (!message) {
     return;
   }
@@ -310,7 +312,7 @@ async function _addAttachmentToMessage(message, attachment, { type, index }) {
 
     const existingAvatar = group.avatar;
     if (existingAvatar && existingAvatar.path) {
-      await Signal.Migrations.deleteAttachmentData(existingAvatar.path);
+      await window.Signal.Migrations.deleteAttachmentData(existingAvatar.path);
     }
 
     _replaceAttachment(group, 'avatar', attachment, logPrefix);
@@ -322,7 +324,7 @@ async function _addAttachmentToMessage(message, attachment, { type, index }) {
   );
 }
 
-function _replaceAttachment(object, key, newAttachment, logPrefix) {
+function _replaceAttachment(object: any, key: any, newAttachment: any, logPrefix: any) {
   const oldAttachment = object[key];
   if (oldAttachment && oldAttachment.path) {
     logger.warn(
diff --git a/ts/session/utils/index.ts b/ts/session/utils/index.ts
index f60efb67e..037ae59ae 100644
--- a/ts/session/utils/index.ts
+++ b/ts/session/utils/index.ts
@@ -9,6 +9,7 @@ import * as ToastUtils from './Toast';
 import * as UserUtils from './User';
 import * as SyncUtils from './syncUtils';
 import * as AttachmentsV2Utils from './AttachmentsV2';
+import * as AttachmentDownloads from './AttachmentsDownload';
 
 export * from './Attachments';
 export * from './TypedEmitter';
@@ -26,4 +27,5 @@ export {
   UserUtils,
   SyncUtils,
   AttachmentsV2Utils,
+  AttachmentDownloads,
 };