diff --git a/ts/background.ts b/ts/background.ts
index 7db5ebe1ff03..50b6ba4155df 100644
--- a/ts/background.ts
+++ b/ts/background.ts
@@ -128,7 +128,6 @@ import type { ViewOnceOpenSyncAttributesType } from './messageModifiers/ViewOnce
 import { ReadStatus } from './messages/MessageReadStatus';
 import type { SendStateByConversationId } from './messages/MessageSendState';
 import { SendStatus } from './messages/MessageSendState';
-import * as AttachmentDownloads from './messageModifiers/AttachmentDownloads';
 import * as Stickers from './types/Stickers';
 import * as Errors from './types/errors';
 import { SignalService as Proto } from './protobuf';
@@ -197,6 +196,7 @@ import {
 } from './util/callDisposition';
 import { deriveStorageServiceKey } from './Crypto';
 import { getThemeType } from './util/getThemeType';
+import { AttachmentDownloadManager } from './jobs/AttachmentDownloadManager';
 
 export function isOverHourIntoPast(timestamp: number): boolean {
   return isNumber(timestamp) && isOlderThan(timestamp, HOUR);
@@ -715,8 +715,9 @@ export async function startApp(): Promise<void> {
           'background/shutdown: shutdown requested'
         );
 
+        server?.cancelInflightRequests('shutdown');
+
         // Stop background processing
-        void AttachmentDownloads.stop();
         idleDetector.stop();
 
         // Stop processing incoming messages
@@ -793,6 +794,14 @@ export async function startApp(): Promise<void> {
           window.waitForAllWaitBatchers(),
         ]);
 
+        log.info(
+          'background/shutdown: waiting for all attachment downloads to finish'
+        );
+
+        // Since we canceled the inflight requests earlier in shutdown, this should
+        // resolve quickly
+        await AttachmentDownloadManager.stop();
+
         log.info('background/shutdown: closing the database');
 
         // Shut down the data interface cleanly
@@ -1541,7 +1550,7 @@ export async function startApp(): Promise<void> {
       log.info('background: offline');
 
       drop(challengeHandler?.onOffline());
-      drop(AttachmentDownloads.stop());
+      drop(AttachmentDownloadManager.stop());
       drop(messageReceiver?.drain());
 
       if (connectCount === 0) {
@@ -1686,11 +1695,7 @@ export async function startApp(): Promise<void> {
 
       void window.Signal.Services.initializeGroupCredentialFetcher();
 
-      drop(
-        AttachmentDownloads.start({
-          logger: log,
-        })
-      );
+      drop(AttachmentDownloadManager.start());
 
       if (connectCount === 1) {
         Stickers.downloadQueuedPacks();
diff --git a/ts/components/conversation/Timeline.tsx b/ts/components/conversation/Timeline.tsx
index 9366f129fb8b..065aad14a2f6 100644
--- a/ts/components/conversation/Timeline.tsx
+++ b/ts/components/conversation/Timeline.tsx
@@ -112,6 +112,7 @@ type PropsHousekeepingType = {
   i18n: LocalizerType;
   theme: ThemeType;
 
+  updateVisibleMessages?: (messageIds: Array<string>) => void;
   renderCollidingAvatars: (_: {
     conversationIds: ReadonlyArray<string>;
   }) => JSX.Element;
@@ -371,6 +372,7 @@ export class Timeline extends React.Component<
 
     const intersectionRatios = new Map<Element, number>();
 
+    this.props.updateVisibleMessages?.([]);
     const intersectionObserverCallback: IntersectionObserverCallback =
       entries => {
         // The first time this callback is called, we'll get entries in observation order
@@ -384,12 +386,16 @@ export class Timeline extends React.Component<
         let oldestPartiallyVisible: undefined | Element;
         let newestPartiallyVisible: undefined | Element;
         let newestFullyVisible: undefined | Element;
-
+        const visibleMessageIds: Array<string> = [];
         for (const [element, intersectionRatio] of intersectionRatios) {
           if (intersectionRatio === 0) {
             continue;
           }
 
+          const messageId = getMessageIdFromElement(element);
+          if (messageId) {
+            visibleMessageIds.push(messageId);
+          }
           // We use this "at bottom detector" for two reasons, both for performance. It's
           //   usually faster to use an `IntersectionObserver` instead of a scroll event,
           //   and we want to do that here.
@@ -409,6 +415,8 @@ export class Timeline extends React.Component<
           }
         }
 
+        this.props.updateVisibleMessages?.(visibleMessageIds);
+
         // If a message is fully visible, then you can see its bottom. If not, there's a
         //   very tall message around. We assume you can see the bottom of a message if
         //   (1) another message is partly visible right below it, or (2) you're near the
@@ -554,6 +562,7 @@ export class Timeline extends React.Component<
 
     this.intersectionObserver?.disconnect();
     this.cleanupGroupCallPeekTimeouts();
+    this.props.updateVisibleMessages?.([]);
   }
 
   public override getSnapshotBeforeUpdate(
diff --git a/ts/jobs/AttachmentDownloadManager.ts b/ts/jobs/AttachmentDownloadManager.ts
new file mode 100644
index 000000000000..fd5d475cb037
--- /dev/null
+++ b/ts/jobs/AttachmentDownloadManager.ts
@@ -0,0 +1,629 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+import { omit } from 'lodash';
+
+import { drop } from '../util/drop';
+import * as durations from '../util/durations';
+import { missingCaseError } from '../util/missingCaseError';
+import { clearTimeoutIfNecessary } from '../util/clearTimeoutIfNecessary';
+import * as log from '../logging/log';
+import {
+  type AttachmentDownloadJobTypeType,
+  type AttachmentDownloadJobType,
+  attachmentDownloadJobSchema,
+} from '../types/AttachmentDownload';
+import {
+  AttachmentNotFoundOnCdnError,
+  downloadAttachment,
+} from '../util/downloadAttachment';
+import dataInterface from '../sql/Client';
+import { getValue } from '../RemoteConfig';
+
+import {
+  explodePromise,
+  type ExplodePromiseResultType,
+} from '../util/explodePromise';
+import { isInCall as isInCallSelector } from '../state/selectors/calling';
+import {
+  type ExponentialBackoffOptionsType,
+  exponentialBackoffSleepTime,
+} from '../util/exponentialBackoff';
+import { AttachmentSizeError, type AttachmentType } from '../types/Attachment';
+import { __DEPRECATED$getMessageById } from '../messages/getMessageById';
+import type { MessageModel } from '../models/messages';
+import {
+  KIBIBYTE,
+  getMaximumIncomingAttachmentSizeInKb,
+  getMaximumIncomingTextAttachmentSizeInKb,
+} from '../types/AttachmentSize';
+import { addAttachmentToMessage } from '../messageModifiers/AttachmentDownloads';
+import * as Errors from '../types/errors';
+import { redactGenericText } from '../util/privacy';
+
+export enum AttachmentDownloadUrgency {
+  IMMEDIATE = 'immediate',
+  STANDARD = 'standard',
+}
+
+const TICK_INTERVAL = durations.MINUTE;
+const MAX_CONCURRENT_JOBS = 3;
+
+type AttachmentDownloadJobIdentifiersType = Pick<
+  AttachmentDownloadJobType,
+  'messageId' | 'attachmentType' | 'digest'
+>;
+
+// Type for adding a new job
+export type NewAttachmentDownloadJobType = {
+  attachment: AttachmentType;
+  messageId: string;
+  receivedAt: number;
+  sentAt: number;
+  attachmentType: AttachmentDownloadJobTypeType;
+  urgency?: AttachmentDownloadUrgency;
+};
+
+const RETRY_CONFIG: Record<
+  'default',
+  { maxRetries: number; backoffConfig: ExponentialBackoffOptionsType }
+> = {
+  default: {
+    maxRetries: 4,
+    backoffConfig: {
+      // 30 seconds, 5 minutes, 50 minutes, (max) 6 hrs
+      multiplier: 10,
+      firstBackoffTime: 30 * durations.SECOND,
+      maxBackoffTime: 6 * durations.HOUR,
+    },
+  },
+};
+
+type AttachmentDownloadManagerParamsType = {
+  getNextJobs: (options: {
+    limit: number;
+    prioritizeMessageIds?: Array<string>;
+    timestamp?: number;
+  }) => Promise<Array<AttachmentDownloadJobType>>;
+
+  saveJob: (job: AttachmentDownloadJobType) => Promise<void>;
+  removeJob: (job: AttachmentDownloadJobType) => Promise<unknown>;
+  runJob: (
+    job: AttachmentDownloadJobType,
+    isLastAttempt: boolean
+  ) => Promise<JobResultType>;
+  isInCall: () => boolean;
+  beforeStart?: () => Promise<void>;
+  maxAttempts: number;
+};
+export type JobResultType = { status: 'retry' | 'finished' };
+export class AttachmentDownloadManager {
+  private static _instance: AttachmentDownloadManager | undefined;
+  private visibleTimelineMessages: Array<string> = [];
+  private enabled: boolean = false;
+  private activeJobs: Map<
+    string,
+    {
+      completionPromise: ExplodePromiseResultType<void>;
+      job: AttachmentDownloadJobType;
+    }
+  > = new Map();
+  private timeout: NodeJS.Timeout | null = null;
+  private jobStartPromises: Map<string, ExplodePromiseResultType<void>> =
+    new Map();
+  private jobCompletePromises: Map<string, ExplodePromiseResultType<void>> =
+    new Map();
+
+  static defaultParams: AttachmentDownloadManagerParamsType = {
+    beforeStart: dataInterface.resetAttachmentDownloadActive,
+    getNextJobs: dataInterface.getNextAttachmentDownloadJobs,
+    saveJob: dataInterface.saveAttachmentDownloadJob,
+    removeJob: dataInterface.removeAttachmentDownloadJob,
+    runJob: runDownloadAttachmentJob,
+    isInCall: () => {
+      const reduxState = window.reduxStore?.getState();
+      if (reduxState) {
+        return isInCallSelector(reduxState);
+      }
+      return false;
+    },
+    maxAttempts: RETRY_CONFIG.default.maxRetries + 1,
+  };
+
+  readonly getNextJobs: AttachmentDownloadManagerParamsType['getNextJobs'];
+  readonly saveJob: AttachmentDownloadManagerParamsType['saveJob'];
+  readonly removeJob: AttachmentDownloadManagerParamsType['removeJob'];
+  readonly runJob: AttachmentDownloadManagerParamsType['runJob'];
+  readonly beforeStart: AttachmentDownloadManagerParamsType['beforeStart'];
+  readonly isInCall: AttachmentDownloadManagerParamsType['isInCall'];
+  readonly maxAttempts: number;
+
+  constructor(
+    params: AttachmentDownloadManagerParamsType = AttachmentDownloadManager.defaultParams
+  ) {
+    this.getNextJobs = params.getNextJobs;
+    this.saveJob = params.saveJob;
+    this.removeJob = params.removeJob;
+    this.runJob = params.runJob;
+    this.beforeStart = params.beforeStart;
+    this.isInCall = params.isInCall;
+    this.maxAttempts = params.maxAttempts;
+  }
+
+  async start(): Promise<void> {
+    this.enabled = true;
+    await this.beforeStart?.();
+    this.tick();
+  }
+
+  async stop(): Promise<void> {
+    this.enabled = false;
+    clearTimeoutIfNecessary(this.timeout);
+    this.timeout = null;
+    await Promise.all(
+      [...this.activeJobs.values()].map(
+        ({ completionPromise }) => completionPromise.promise
+      )
+    );
+  }
+
+  tick(): void {
+    clearTimeoutIfNecessary(this.timeout);
+    this.timeout = null;
+    drop(this.maybeStartJobs());
+    this.timeout = setTimeout(() => this.tick(), TICK_INTERVAL);
+  }
+
+  async addJob(
+    newJobData: NewAttachmentDownloadJobType
+  ): Promise<AttachmentType> {
+    const {
+      attachment,
+      messageId,
+      attachmentType,
+      receivedAt,
+      sentAt,
+      urgency = AttachmentDownloadUrgency.STANDARD,
+    } = newJobData;
+    const parseResult = attachmentDownloadJobSchema.safeParse({
+      messageId,
+      receivedAt,
+      sentAt,
+      attachmentType,
+      digest: attachment.digest,
+      contentType: attachment.contentType,
+      size: attachment.size,
+      attachment,
+      active: false,
+      attempts: 0,
+      retryAfter: null,
+      lastAttemptTimestamp: null,
+    });
+
+    if (!parseResult.success) {
+      log.error(
+        `AttachmentDownloadManager/addJob(${sentAt}.${attachmentType}): invalid data`,
+        parseResult.error
+      );
+      return attachment;
+    }
+
+    const newJob = parseResult.data;
+    const jobIdForLogging = getJobIdForLogging(newJob);
+    const logId = `AttachmentDownloadManager/addJob(${jobIdForLogging})`;
+
+    try {
+      const runningJob = this.getRunningJob(newJob);
+      if (runningJob) {
+        log.info(`${logId}: already running; resetting attempts`);
+        runningJob.attempts = 0;
+
+        await this.saveJob({
+          ...runningJob,
+          attempts: 0,
+        });
+        return attachment;
+      }
+
+      await this.saveJob(newJob);
+    } catch (e) {
+      log.error(`${logId}: error saving job`, Errors.toLogFormat(e));
+    }
+
+    switch (urgency) {
+      case AttachmentDownloadUrgency.IMMEDIATE:
+        log.info(`${logId}: starting job immediately`);
+        drop(this.startJob(newJob));
+        break;
+      case AttachmentDownloadUrgency.STANDARD:
+        drop(this.maybeStartJobs());
+        break;
+      default:
+        throw missingCaseError(urgency);
+    }
+
+    return {
+      ...attachment,
+      pending: true,
+    };
+  }
+
+  updateVisibleTimelineMessages(messageIds: Array<string>): void {
+    this.visibleTimelineMessages = messageIds;
+  }
+
+  // used in testing
+  public waitForJobToBeStarted(job: AttachmentDownloadJobType): Promise<void> {
+    const id = this.getJobIdIncludingAttempts(job);
+    const existingPromise = this.jobStartPromises.get(id)?.promise;
+    if (existingPromise) {
+      return existingPromise;
+    }
+    const { promise, resolve, reject } = explodePromise<void>();
+    this.jobStartPromises.set(id, { promise, resolve, reject });
+    return promise;
+  }
+
+  public waitForJobToBeCompleted(
+    job: AttachmentDownloadJobType
+  ): Promise<void> {
+    const id = this.getJobIdIncludingAttempts(job);
+    const existingPromise = this.jobCompletePromises.get(id)?.promise;
+    if (existingPromise) {
+      return existingPromise;
+    }
+    const { promise, resolve, reject } = explodePromise<void>();
+    this.jobCompletePromises.set(id, { promise, resolve, reject });
+    return promise;
+  }
+
+  // Private methods
+
+  // maybeStartJobs is called:
+  // 1. every minute (via tick)
+  // 2. after a job is added (via addJob)
+  // 3. after a job finishes (via startJob)
+  // preventing re-entrancy allow us to simplify some logic and ensure we don't try to
+  // start too many jobs
+  private _inMaybeStartJobs = false;
+  private async maybeStartJobs(): Promise<void> {
+    if (this._inMaybeStartJobs) {
+      return;
+    }
+
+    try {
+      this._inMaybeStartJobs = true;
+
+      if (!this.enabled) {
+        log.info(
+          'AttachmentDownloadManager/_maybeStartJobs: not enabled, returning'
+        );
+        return;
+      }
+
+      if (this.isInCall()) {
+        log.info(
+          'AttachmentDownloadManager/_maybeStartJobs: holding off on starting new jobs; in call'
+        );
+        return;
+      }
+
+      const numJobsToStart = this.getMaximumNumberOfJobsToStart();
+
+      if (numJobsToStart <= 0) {
+        return;
+      }
+
+      const nextJobs = await this.getNextJobs({
+        limit: numJobsToStart,
+        // TODO (DESKTOP-6912): we'll want to prioritize more than just visible timeline
+        // messages, including:
+        // - media opened in lightbox
+        // - media for stories
+        prioritizeMessageIds: [...this.visibleTimelineMessages],
+        timestamp: Date.now(),
+      });
+
+      // TODO (DESKTOP-6913): if a prioritized job is selected, we will to update the
+      // in-memory job with that information so we can handle it differently, including
+      // e.g. downloading a thumbnail before the full-size version
+      for (const job of nextJobs) {
+        drop(this.startJob(job));
+      }
+    } finally {
+      this._inMaybeStartJobs = false;
+    }
+  }
+
+  private async startJob(job: AttachmentDownloadJobType): Promise<void> {
+    const logId = `AttachmentDownloadManager/startJob(${getJobIdForLogging(
+      job
+    )})`;
+    if (this.isJobRunning(job)) {
+      log.info(`${logId}: job is already running`);
+      return;
+    }
+    const isLastAttempt = job.attempts + 1 >= this.maxAttempts;
+
+    try {
+      log.info(`${logId}: starting job`);
+      this.addRunningJob(job);
+      await this.saveJob({ ...job, active: true });
+      this.handleJobStartPromises(job);
+
+      const { status } = await this.runJob(job, isLastAttempt);
+      log.info(`${logId}: job completed with status: ${status}`);
+
+      switch (status) {
+        case 'finished':
+          await this.removeJob(job);
+          return;
+        case 'retry':
+          if (isLastAttempt) {
+            throw new Error('Cannot retry on last attempt');
+          }
+          await this.retryJobLater(job);
+          return;
+        default:
+          throw missingCaseError(status);
+      }
+    } catch (e) {
+      log.error(`${logId}: error when running job`, e);
+      if (isLastAttempt) {
+        await this.removeJob(job);
+      } else {
+        await this.retryJobLater(job);
+      }
+    } finally {
+      this.removeRunningJob(job);
+      drop(this.maybeStartJobs());
+    }
+  }
+
+  private async retryJobLater(job: AttachmentDownloadJobType) {
+    const now = Date.now();
+    await this.saveJob({
+      ...job,
+      active: false,
+      attempts: job.attempts + 1,
+      // TODO (DESKTOP-6845): adjust retry based on job type (e.g. backup)
+      retryAfter:
+        now +
+        exponentialBackoffSleepTime(
+          job.attempts + 1,
+          RETRY_CONFIG.default.backoffConfig
+        ),
+      lastAttemptTimestamp: now,
+    });
+  }
+  private getActiveJobCount(): number {
+    return this.activeJobs.size;
+  }
+
+  private getMaximumNumberOfJobsToStart(): number {
+    return MAX_CONCURRENT_JOBS - this.getActiveJobCount();
+  }
+
+  private getRunningJob(
+    job: AttachmentDownloadJobIdentifiersType
+  ): AttachmentDownloadJobType | undefined {
+    const id = this.getJobId(job);
+    return this.activeJobs.get(id)?.job;
+  }
+
+  private isJobRunning(job: AttachmentDownloadJobType): boolean {
+    return Boolean(this.getRunningJob(job));
+  }
+
+  private removeRunningJob(job: AttachmentDownloadJobType) {
+    const idWithAttempts = this.getJobIdIncludingAttempts(job);
+    this.jobCompletePromises.get(idWithAttempts)?.resolve();
+    this.jobCompletePromises.delete(idWithAttempts);
+
+    const id = this.getJobId(job);
+    this.activeJobs.get(id)?.completionPromise.resolve();
+    this.activeJobs.delete(id);
+  }
+
+  private addRunningJob(job: AttachmentDownloadJobType) {
+    if (this.isJobRunning(job)) {
+      const jobIdForLogging = getJobIdForLogging(job);
+      log.warn(
+        `attachmentDownloads/_addRunningJob: job ${jobIdForLogging} is already running`
+      );
+    }
+    this.activeJobs.set(this.getJobId(job), {
+      completionPromise: explodePromise<void>(),
+      job,
+    });
+  }
+
+  private handleJobStartPromises(job: AttachmentDownloadJobType) {
+    const id = this.getJobIdIncludingAttempts(job);
+    this.jobStartPromises.get(id)?.resolve();
+    this.jobStartPromises.delete(id);
+  }
+
+  private getJobIdIncludingAttempts(job: AttachmentDownloadJobType) {
+    return `${this.getJobId(job)}.${job.attempts}`;
+  }
+
+  private getJobId(job: AttachmentDownloadJobIdentifiersType): string {
+    const { messageId, attachmentType, digest } = job;
+    return `${messageId}.${attachmentType}.${digest}`;
+  }
+
+  // Static methods
+  static get instance(): AttachmentDownloadManager {
+    if (!AttachmentDownloadManager._instance) {
+      AttachmentDownloadManager._instance = new AttachmentDownloadManager();
+    }
+    return AttachmentDownloadManager._instance;
+  }
+
+  static async start(): Promise<void> {
+    log.info('AttachmentDownloadManager/starting');
+    await AttachmentDownloadManager.instance.start();
+  }
+
+  static async stop(): Promise<void> {
+    log.info('AttachmentDownloadManager/stopping');
+    return AttachmentDownloadManager._instance?.stop();
+  }
+
+  static async addJob(
+    newJob: NewAttachmentDownloadJobType
+  ): Promise<AttachmentType> {
+    return AttachmentDownloadManager.instance.addJob(newJob);
+  }
+
+  static updateVisibleTimelineMessages(messageIds: Array<string>): void {
+    AttachmentDownloadManager.instance.updateVisibleTimelineMessages(
+      messageIds
+    );
+  }
+}
+
+async function runDownloadAttachmentJob(
+  job: AttachmentDownloadJobType,
+  isLastAttempt: boolean
+): Promise<JobResultType> {
+  const jobIdForLogging = getJobIdForLogging(job);
+  const logId = `attachment_downloads/runDownloadAttachmentJob/${jobIdForLogging}`;
+
+  const message = await __DEPRECATED$getMessageById(job.messageId);
+
+  if (!message) {
+    log.error(`${logId} message not found`);
+    return { status: 'finished' };
+  }
+
+  try {
+    log.info(`${logId}: Starting job`);
+    await runDownloadAttachmentJobInner(job, message);
+    return { status: 'finished' };
+  } catch (error) {
+    log.error(
+      `${logId}: Failed to download attachment, attempt ${job.attempts}:`,
+      Errors.toLogFormat(error)
+    );
+
+    if (error instanceof AttachmentSizeError) {
+      await addAttachmentToMessage(
+        message,
+        _markAttachmentAsTooBig(job.attachment),
+        { type: job.attachmentType }
+      );
+      return { status: 'finished' };
+    }
+
+    if (error instanceof AttachmentNotFoundOnCdnError) {
+      await addAttachmentToMessage(
+        message,
+        _markAttachmentAsPermanentlyErrored(job.attachment),
+        { type: job.attachmentType }
+      );
+
+      return { status: 'finished' };
+    }
+
+    if (isLastAttempt) {
+      await addAttachmentToMessage(
+        message,
+        _markAttachmentAsTransientlyErrored(job.attachment),
+        { type: job.attachmentType }
+      );
+      return { status: 'finished' };
+    }
+
+    // Remove `pending` flag from the attachment and retry later
+    await addAttachmentToMessage(
+      message,
+      {
+        ...job.attachment,
+        pending: false,
+      },
+      { type: job.attachmentType }
+    );
+    return { status: 'retry' };
+  } finally {
+    // This will fail if the message has been deleted before the download finished, which
+    // is good
+    await dataInterface.saveMessage(message.attributes, {
+      ourAci: window.textsecure.storage.user.getCheckedAci(),
+    });
+  }
+}
+
+async function runDownloadAttachmentJobInner(
+  job: AttachmentDownloadJobType,
+  message: MessageModel
+): Promise<void> {
+  const { messageId, attachment, attachmentType: type } = job;
+
+  const jobIdForLogging = getJobIdForLogging(job);
+  const logId = `attachment_downloads/_runDownloadJobInner(${jobIdForLogging})`;
+
+  if (!job || !attachment || !messageId) {
+    throw new Error(`${logId}: Key information required for job was missing.`);
+  }
+
+  log.info(`${logId}: starting`);
+
+  const maxInKib = getMaximumIncomingAttachmentSizeInKb(getValue);
+  const maxTextAttachmentSizeInKib =
+    getMaximumIncomingTextAttachmentSizeInKb(getValue);
+
+  const { size } = attachment;
+  const sizeInKib = size / KIBIBYTE;
+
+  if (!Number.isFinite(size) || size < 0 || sizeInKib > maxInKib) {
+    throw new AttachmentSizeError(
+      `${logId}: Attachment was ${sizeInKib}kib, max is ${maxInKib}kib`
+    );
+  }
+  if (type === 'long-message' && sizeInKib > maxTextAttachmentSizeInKib) {
+    throw new AttachmentSizeError(
+      `${logId}: Text attachment was ${sizeInKib}kib, max is ${maxTextAttachmentSizeInKib}kib`
+    );
+  }
+
+  await addAttachmentToMessage(
+    message,
+    { ...attachment, pending: true },
+    { type }
+  );
+
+  const downloaded = await downloadAttachment(attachment);
+
+  const upgradedAttachment =
+    await window.Signal.Migrations.processNewAttachment(downloaded);
+
+  await addAttachmentToMessage(message, omit(upgradedAttachment, 'error'), {
+    type,
+  });
+}
+
+function _markAttachmentAsTooBig(attachment: AttachmentType): AttachmentType {
+  return {
+    ..._markAttachmentAsPermanentlyErrored(attachment),
+    wasTooBig: true,
+  };
+}
+
+function _markAttachmentAsPermanentlyErrored(
+  attachment: AttachmentType
+): AttachmentType {
+  return { ...omit(attachment, ['key', 'id']), pending: false, error: true };
+}
+
+function _markAttachmentAsTransientlyErrored(
+  attachment: AttachmentType
+): AttachmentType {
+  return { ...attachment, pending: false, error: true };
+}
+
+function getJobIdForLogging(job: AttachmentDownloadJobType): string {
+  const { sentAt, attachmentType, digest } = job;
+  const redactedDigest = redactGenericText(digest);
+  return `${sentAt}.${attachmentType}.${redactedDigest}`;
+}
diff --git a/ts/messageModifiers/AttachmentDownloads.ts b/ts/messageModifiers/AttachmentDownloads.ts
index a8bf656bdde3..53c5ba105725 100644
--- a/ts/messageModifiers/AttachmentDownloads.ts
+++ b/ts/messageModifiers/AttachmentDownloads.ts
@@ -1,530 +1,23 @@
 // Copyright 2019 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
-
-import { isNumber, omit } from 'lodash';
-import { v4 as getGuid } from 'uuid';
-
-import dataInterface from '../sql/Client';
-import * as durations from '../util/durations';
-import { clearTimeoutIfNecessary } from '../util/clearTimeoutIfNecessary';
-import { strictAssert } from '../util/assert';
-import { downloadAttachment } from '../util/downloadAttachment';
+import * as log from '../logging/log';
 import * as Bytes from '../Bytes';
-import type {
-  AttachmentDownloadJobType,
-  AttachmentDownloadJobTypeType,
-} from '../sql/Interface';
+import type { AttachmentDownloadJobTypeType } from '../types/AttachmentDownload';
 
-import { getValue } from '../RemoteConfig';
 import type { MessageModel } from '../models/messages';
 import type { AttachmentType } from '../types/Attachment';
-import {
-  AttachmentSizeError,
-  getAttachmentSignature,
-  isDownloaded,
-} from '../types/Attachment';
-import * as Errors from '../types/errors';
-import type { LoggerType } from '../types/Logging';
-import * as log from '../logging/log';
-import {
-  KIBIBYTE,
-  getMaximumIncomingAttachmentSizeInKb,
-  getMaximumIncomingTextAttachmentSizeInKb,
-} from '../types/AttachmentSize';
-import { redactCdnKey } from '../util/privacy';
+import { getAttachmentSignature, isDownloaded } from '../types/Attachment';
 
-const {
-  getMessageById,
-  getAttachmentDownloadJobById,
-  getNextAttachmentDownloadJobs,
-  removeAttachmentDownloadJob,
-  resetAttachmentDownloadPending,
-  saveAttachmentDownloadJob,
-  saveMessage,
-  setAttachmentDownloadJobPending,
-} = dataInterface;
-
-const MAX_ATTACHMENT_JOB_PARALLELISM = 3;
-
-const TICK_INTERVAL = durations.MINUTE;
-
-const RETRY_BACKOFF: Record<number, number> = {
-  1: 30 * durations.SECOND,
-  2: 30 * durations.MINUTE,
-  3: 6 * durations.HOUR,
-};
-
-let enabled = false;
-let timeout: NodeJS.Timeout | null;
-let logger: LoggerType;
-const _activeAttachmentDownloadJobs: Record<string, Promise<void> | undefined> =
-  {};
-
-type StartOptionsType = {
-  logger: LoggerType;
-};
-
-export async function start(options: StartOptionsType): Promise<void> {
-  ({ logger } = options);
-  if (!logger) {
-    throw new Error('attachment_downloads/start: logger must be provided!');
-  }
-
-  logger.info('attachment_downloads/start: enabling');
-  enabled = true;
-  await resetAttachmentDownloadPending();
-
-  void _tick();
-}
-
-export async function stop(): Promise<void> {
-  // If `.start()` wasn't called - the `logger` is `undefined`
-  if (logger) {
-    logger.info('attachment_downloads/stop: disabling');
-  }
-  enabled = false;
-  clearTimeoutIfNecessary(timeout);
-  timeout = null;
-}
-
-export async function addJob(
-  attachment: AttachmentType,
-  // TODO: DESKTOP-5279
-  job: { messageId: string; type: AttachmentDownloadJobTypeType; index: number }
-): Promise<AttachmentType> {
-  if (!attachment) {
-    throw new Error('attachments_download/addJob: attachment is required');
-  }
-
-  const { messageId, type, index } = job;
-  if (!messageId) {
-    throw new Error('attachments_download/addJob: job.messageId is required');
-  }
-  if (!type) {
-    throw new Error('attachments_download/addJob: job.type is required');
-  }
-  if (!isNumber(index)) {
-    throw new Error('attachments_download/addJob: index must be a number');
-  }
-
-  if (attachment.downloadJobId) {
-    let existingJob = await getAttachmentDownloadJobById(
-      attachment.downloadJobId
-    );
-    if (existingJob) {
-      // Reset job attempts through user's explicit action
-      existingJob = { ...existingJob, attempts: 0 };
-
-      if (_activeAttachmentDownloadJobs[existingJob.id]) {
-        logger.info(
-          `attachment_downloads/addJob: ${existingJob.id} already running`
-        );
-      } else {
-        logger.info(
-          `attachment_downloads/addJob: restarting existing job ${existingJob.id}`
-        );
-        _activeAttachmentDownloadJobs[existingJob.id] = _runJob(existingJob);
-      }
-
-      return {
-        ...attachment,
-        pending: true,
-      };
-    }
-  }
-
-  const id = getGuid();
-  const timestamp = Date.now();
-  const toSave: AttachmentDownloadJobType = {
-    ...job,
-    id,
-    attachment,
-    timestamp,
-    pending: 0,
-    attempts: 0,
-  };
-
-  await saveAttachmentDownloadJob(toSave);
-
-  void _maybeStartJob();
-
-  return {
-    ...attachment,
-    pending: true,
-    downloadJobId: id,
-  };
-}
-
-async function _tick(): Promise<void> {
-  clearTimeoutIfNecessary(timeout);
-  timeout = null;
-
-  void _maybeStartJob();
-  timeout = setTimeout(_tick, TICK_INTERVAL);
-}
-
-async function _maybeStartJob(): Promise<void> {
-  if (!enabled) {
-    logger.info('attachment_downloads/_maybeStartJob: not enabled, returning');
-    return;
-  }
-
-  const jobCount = getActiveJobCount();
-  const limit = MAX_ATTACHMENT_JOB_PARALLELISM - jobCount;
-  if (limit <= 0) {
-    logger.info(
-      'attachment_downloads/_maybeStartJob: reached active job limit, waiting'
-    );
-    return;
-  }
-
-  const nextJobs = await getNextAttachmentDownloadJobs(limit);
-  if (nextJobs.length <= 0) {
-    logger.info(
-      'attachment_downloads/_maybeStartJob: no attachment jobs to run'
-    );
-    return;
-  }
-
-  // To prevent the race condition caused by two parallel database calls, eached kicked
-  //   off because the jobCount wasn't at the max.
-  const secondJobCount = getActiveJobCount();
-  const needed = MAX_ATTACHMENT_JOB_PARALLELISM - secondJobCount;
-  if (needed <= 0) {
-    logger.info(
-      'attachment_downloads/_maybeStartJob: reached active job limit after ' +
-        'db query, waiting'
-    );
-    return;
-  }
-
-  const jobs = nextJobs.slice(0, Math.min(needed, nextJobs.length));
-
-  logger.info(
-    `attachment_downloads/_maybeStartJob: starting ${jobs.length} jobs`
-  );
-
-  for (let i = 0, max = jobs.length; i < max; i += 1) {
-    const job = jobs[i];
-    const existing = _activeAttachmentDownloadJobs[job.id];
-    if (existing) {
-      logger.warn(
-        `attachment_downloads/_maybeStartJob: Job ${job.id} is already running`
-      );
-    } else {
-      logger.info(
-        `attachment_downloads/_maybeStartJob: Starting job ${job.id}`
-      );
-      const promise = _runJob(job);
-      _activeAttachmentDownloadJobs[job.id] = promise;
-
-      const postProcess = async () => {
-        const logId = `attachment_downloads/_maybeStartJob/postProcess/${job.id}`;
-        try {
-          await promise;
-          if (_activeAttachmentDownloadJobs[job.id]) {
-            throw new Error(
-              `${logId}: Active attachments jobs list still has this job!`
-            );
-          }
-        } catch (error: unknown) {
-          log.error(
-            `${logId}: Download job threw an error, deleting.`,
-            Errors.toLogFormat(error)
-          );
-
-          delete _activeAttachmentDownloadJobs[job.id];
-          try {
-            await _markAttachmentAsFailed(job);
-          } catch (deleteError) {
-            log.error(
-              `${logId}: Failed to delete attachment job`,
-              Errors.toLogFormat(deleteError)
-            );
-          } finally {
-            void _maybeStartJob();
-          }
-        }
-      };
-
-      // Note: intentionally not awaiting
-      void postProcess();
-    }
-  }
-}
-
-async function _runJob(job?: AttachmentDownloadJobType): Promise<void> {
-  if (!job) {
-    log.warn('attachment_downloads/_runJob: Job was missing!');
-    return;
-  }
-
-  const { id, messageId, attachment, type, index, attempts } = job;
-  let message;
-
-  try {
-    if (!job || !attachment || !messageId) {
-      throw new Error(
-        `_runJob: Key information required for job was missing. Job id: ${id}`
-      );
-    }
-
-    const pending = true;
-    await setAttachmentDownloadJobPending(id, pending);
-
-    message = await _getMessageById(id, messageId);
-    logger.info(
-      'attachment_downloads/_runJob' +
-        `(jobId: ${id}, type: ${type}, index: ${index},` +
-        ` cdnKey: ${
-          attachment.cdnKey ? redactCdnKey(attachment.cdnKey) : null
-        },` +
-        ` messageTimestamp: ${message?.attributes.timestamp}): starting`
-    );
-
-    if (!message) {
-      return;
-    }
-
-    let downloaded: AttachmentType | null = null;
-
-    try {
-      const maxInKib = getMaximumIncomingAttachmentSizeInKb(getValue);
-      const maxTextAttachmentSizeInKib =
-        getMaximumIncomingTextAttachmentSizeInKb(getValue);
-
-      const { size } = attachment;
-      const sizeInKib = size / KIBIBYTE;
-
-      if (!Number.isFinite(size) || size < 0 || sizeInKib > maxInKib) {
-        throw new AttachmentSizeError(
-          `Attachment Job ${id}: Attachment was ${sizeInKib}kib, max is ${maxInKib}kib`
-        );
-      }
-      if (type === 'long-message' && sizeInKib > maxTextAttachmentSizeInKib) {
-        throw new AttachmentSizeError(
-          `Attachment Job ${id}: Text attachment was ${sizeInKib}kib, max is ${maxTextAttachmentSizeInKib}kib`
-        );
-      }
-
-      await _addAttachmentToMessage(
-        message,
-        { ...attachment, pending: true },
-        { type, index }
-      );
-
-      // If the download is bigger than expected, we'll stop in the middle
-      downloaded = await downloadAttachment(attachment);
-    } catch (error) {
-      if (error instanceof AttachmentSizeError) {
-        log.error(Errors.toLogFormat(error));
-        await _addAttachmentToMessage(
-          message,
-          _markAttachmentAsTooBig(attachment),
-          { type, index }
-        );
-        await _finishJob(message, id);
-        return;
-      }
-
-      throw error;
-    }
-
-    if (!downloaded) {
-      logger.warn(
-        `attachment_downloads/_runJob(${id}): Got 404 from server for CDN ${
-          attachment.cdnNumber
-        }, marking attachment ${
-          attachment.cdnId || attachment.cdnKey
-        } from message ${message.idForLogging()} as permanent error`
-      );
-
-      await _addAttachmentToMessage(
-        message,
-        _markAttachmentAsPermanentError(attachment),
-        { type, index }
-      );
-      await _finishJob(message, id);
-      return;
-    }
-
-    logger.info(
-      `attachment_downloads/_runJob(${id}): processing new attachment` +
-        ` of type: ${type}`
-    );
-    const upgradedAttachment =
-      await window.Signal.Migrations.processNewAttachment(downloaded);
-
-    await _addAttachmentToMessage(message, omit(upgradedAttachment, 'error'), {
-      type,
-      index,
-    });
-
-    await _finishJob(message, id);
-  } catch (error) {
-    const logId = message ? message.idForLogging() : id || '<no id>';
-    const currentAttempt = (attempts || 0) + 1;
-
-    if (currentAttempt >= 3) {
-      logger.error(
-        `attachment_downloads/runJob(${id}): ${currentAttempt} failed ` +
-          `attempts, marking attachment from message ${logId} as ` +
-          'error:',
-        Errors.toLogFormat(error)
-      );
-
-      try {
-        await _addAttachmentToMessage(
-          message,
-          _markAttachmentAsTransientError(attachment),
-          { type, index }
-        );
-      } finally {
-        await _finishJob(message, id);
-      }
-
-      return;
-    }
-
-    logger.error(
-      `attachment_downloads/_runJob(${id}): Failed to download attachment ` +
-        `type ${type} for message ${logId}, attempt ${currentAttempt}:`,
-      Errors.toLogFormat(error)
-    );
-
-    try {
-      // Remove `pending` flag from the attachment.
-      await _addAttachmentToMessage(
-        message,
-        {
-          ...attachment,
-          downloadJobId: id,
-        },
-        { type, index }
-      );
-      if (message) {
-        await saveMessage(message.attributes, {
-          ourAci: window.textsecure.storage.user.getCheckedAci(),
-        });
-      }
-
-      const failedJob = {
-        ...job,
-        pending: 0,
-        attempts: currentAttempt,
-        timestamp:
-          Date.now() + (RETRY_BACKOFF[currentAttempt] || RETRY_BACKOFF[3]),
-      };
-
-      await saveAttachmentDownloadJob(failedJob);
-    } finally {
-      delete _activeAttachmentDownloadJobs[id];
-      void _maybeStartJob();
-    }
-  }
-}
-
-async function _markAttachmentAsFailed(
-  job: AttachmentDownloadJobType
-): Promise<void> {
-  const { id, messageId, attachment, type, index } = job;
-  const message = await _getMessageById(id, messageId);
-
-  try {
-    if (!message) {
-      return;
-    }
-    await _addAttachmentToMessage(
-      message,
-      _markAttachmentAsPermanentError(attachment),
-      { type, index }
-    );
-  } finally {
-    await _finishJob(message, id);
-  }
-}
-
-async function _getMessageById(
-  id: string,
-  messageId: string
-): Promise<MessageModel | undefined> {
-  const message = window.MessageCache.__DEPRECATED$getById(messageId);
-
-  if (message) {
-    return message;
-  }
-
-  const messageAttributes = await getMessageById(messageId);
-  if (!messageAttributes) {
-    logger.error(
-      `attachment_downloads/_runJob(${id}): ` +
-        'Source message not found, deleting job'
-    );
-    await _finishJob(null, id);
-    return;
-  }
-
-  strictAssert(messageId === messageAttributes.id, 'message id mismatch');
-  return window.MessageCache.__DEPRECATED$register(
-    messageId,
-    messageAttributes,
-    'AttachmentDownloads._getMessageById'
-  );
-}
-
-async function _finishJob(
-  message: MessageModel | null | undefined,
-  id: string
-): Promise<void> {
-  if (message) {
-    logger.info(`attachment_downloads/_finishJob for job id: ${id}`);
-    await saveMessage(message.attributes, {
-      ourAci: window.textsecure.storage.user.getCheckedAci(),
-    });
-  }
-
-  await removeAttachmentDownloadJob(id);
-  delete _activeAttachmentDownloadJobs[id];
-  void _maybeStartJob();
-}
-
-function getActiveJobCount(): number {
-  return Object.keys(_activeAttachmentDownloadJobs).length;
-}
-
-function _markAttachmentAsPermanentError(
-  attachment: AttachmentType
-): AttachmentType {
-  return {
-    ...omit(attachment, ['key', 'id']),
-    error: true,
-  };
-}
-
-function _markAttachmentAsTooBig(attachment: AttachmentType): AttachmentType {
-  return {
-    ...omit(attachment, ['key', 'id']),
-    error: true,
-    wasTooBig: true,
-  };
-}
-
-function _markAttachmentAsTransientError(
-  attachment: AttachmentType
-): AttachmentType {
-  return { ...attachment, error: true };
-}
-
-async function _addAttachmentToMessage(
+export async function addAttachmentToMessage(
   message: MessageModel | null | undefined,
   attachment: AttachmentType,
-  { type, index }: { type: AttachmentDownloadJobTypeType; index: number }
+  { type }: { type: AttachmentDownloadJobTypeType }
 ): Promise<void> {
   if (!message) {
     return;
   }
 
-  const logPrefix = `${message.idForLogging()} (type: ${type}, index: ${index})`;
+  const logPrefix = `${message.idForLogging()} (type: ${type})`;
   const attachmentSignature = getAttachmentSignature(attachment);
 
   if (type === 'long-message') {
@@ -608,7 +101,7 @@ async function _addAttachmentToMessage(
         await window.Signal.Migrations.deleteAttachmentData(attachment.path);
       }
       if (!handledAnywhere) {
-        logger.warn(
+        log.warn(
           `${logPrefix}: Long message attachment found no matching place to apply`
         );
       }
@@ -670,7 +163,7 @@ async function _addAttachmentToMessage(
     }
 
     if (!handledAnywhere) {
-      logger.warn(
+      log.warn(
         `${logPrefix}: 'attachment' type found no matching place to apply`
       );
     }
@@ -727,33 +220,37 @@ async function _addAttachmentToMessage(
   }
 
   if (type === 'contact') {
-    const contact = message.get('contact');
-    if (!contact || contact.length <= index) {
+    const contacts = message.get('contact');
+    if (!contacts?.length) {
+      throw new Error(`${logPrefix}: no contacts, cannot add attachment!`);
+    }
+    let handled = false;
+
+    const newContacts = contacts.map(contact => {
+      if (!contact.avatar?.avatar) {
+        return contact;
+      }
+
+      const existingAttachment = contact.avatar.avatar;
+
+      const newAttachment = maybeReplaceAttachment(existingAttachment);
+      if (existingAttachment !== newAttachment) {
+        handled = true;
+        return {
+          ...contact,
+          avatar: { ...contact.avatar, avatar: newAttachment },
+        };
+      }
+      return contact;
+    });
+
+    if (!handled) {
       throw new Error(
-        `${logPrefix}: contact didn't exist or ${index} was too large`
-      );
-    }
-
-    const item = contact[index];
-    if (item && item.avatar && item.avatar.avatar) {
-      _checkOldAttachment(item.avatar, 'avatar', logPrefix);
-
-      const newContact = [...contact];
-      newContact[index] = {
-        ...item,
-        avatar: {
-          ...item.avatar,
-          avatar: attachment,
-        },
-      };
-
-      message.set({ contact: newContact });
-    } else {
-      logger.warn(
-        `${logPrefix}: Couldn't update contact with avatar attachment for message`
+        `${logPrefix}: Couldn't find matching contact with avatar attachment for message`
       );
     }
 
+    message.set({ contact: newContacts });
     return;
   }
 
@@ -831,20 +328,3 @@ async function _addAttachmentToMessage(
 
   throw new Error(`${logPrefix}: Unknown job type ${type}`);
 }
-
-function _checkOldAttachment(
-  // eslint-disable-next-line @typescript-eslint/no-explicit-any
-  object: any,
-  key: string,
-  logPrefix: string
-): void {
-  const oldAttachment = object[key];
-  if (oldAttachment && oldAttachment.path) {
-    logger.error(
-      `_checkOldAttachment: ${logPrefix} - old attachment already had path, not replacing`
-    );
-    throw new Error(
-      '_checkOldAttachment: old attachment already had path, not replacing'
-    );
-  }
-}
diff --git a/ts/messageModifiers/ViewSyncs.ts b/ts/messageModifiers/ViewSyncs.ts
index 35c9bf1df2c2..d3216c1cdd08 100644
--- a/ts/messageModifiers/ViewSyncs.ts
+++ b/ts/messageModifiers/ViewSyncs.ts
@@ -16,6 +16,7 @@ import { notificationService } from '../services/notifications';
 import { queueAttachmentDownloads } from '../util/queueAttachmentDownloads';
 import { queueUpdateMessage } from '../util/messageBatcher';
 import { generateCacheKey } from './generateCacheKey';
+import { AttachmentDownloadUrgency } from '../jobs/AttachmentDownloadManager';
 
 export type ViewSyncAttributesType = {
   envelopeId: string;
@@ -127,7 +128,8 @@ export async function onSync(sync: ViewSyncAttributesType): Promise<void> {
       const attachments = message.get('attachments');
       if (!attachments?.every(isDownloaded)) {
         const updatedFields = await queueAttachmentDownloads(
-          message.attributes
+          message.attributes,
+          AttachmentDownloadUrgency.STANDARD
         );
         if (updatedFields) {
           message.set(updatedFields);
diff --git a/ts/models/messages.ts b/ts/models/messages.ts
index 75ff28cee318..ea56e038569b 100644
--- a/ts/models/messages.ts
+++ b/ts/models/messages.ts
@@ -157,6 +157,7 @@ import {
   getChangesForPropAtTimestamp,
 } from '../util/editHelpers';
 import { getMessageSentTimestamp } from '../util/getMessageSentTimestamp';
+import type { AttachmentDownloadUrgency } from '../jobs/AttachmentDownloadManager';
 
 /* eslint-disable more/no-then */
 
@@ -1368,8 +1369,10 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
     return hasAttachmentDownloads(this.attributes);
   }
 
-  async queueAttachmentDownloads(): Promise<boolean> {
-    const value = await queueAttachmentDownloads(this.attributes);
+  async queueAttachmentDownloads(
+    urgency?: AttachmentDownloadUrgency
+  ): Promise<boolean> {
+    const value = await queueAttachmentDownloads(this.attributes, urgency);
     if (!value) {
       return false;
     }
@@ -2279,8 +2282,6 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
 
         window.Signal.Data.updateConversation(conversation.attributes);
 
-        const reduxState = window.reduxStore.getState();
-
         const giftBadge = message.get('giftBadge');
         if (giftBadge) {
           const { level } = giftBadge;
@@ -2315,35 +2316,6 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
           }
         }
 
-        // Only queue attachments for downloads if this is a story or
-        // outgoing message or we've accepted the conversation
-        const attachments = this.get('attachments') || [];
-
-        let queueStoryForDownload = false;
-        if (isStory(message.attributes)) {
-          queueStoryForDownload = await shouldDownloadStory(
-            conversation.attributes
-          );
-        }
-
-        const shouldHoldOffDownload =
-          (isStory(message.attributes) && !queueStoryForDownload) ||
-          (!isStory(message.attributes) &&
-            (isImage(attachments) || isVideo(attachments)) &&
-            isInCall(reduxState));
-
-        if (
-          this.hasAttachmentDownloads() &&
-          (conversation.getAccepted() || isOutgoing(message.attributes)) &&
-          !shouldHoldOffDownload
-        ) {
-          if (shouldUseAttachmentDownloadQueue()) {
-            addToAttachmentDownloadQueue(idLog, message);
-          } else {
-            await message.queueAttachmentDownloads();
-          }
-        }
-
         const isFirstRun = true;
         await this.modifyTargetMessage(conversation, isFirstRun);
 
@@ -2365,6 +2337,9 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
 
     log.info('Message saved', this.get('sent_at'));
 
+    // Once the message is saved to DB, we queue attachment downloads
+    await this.handleAttachmentDownloadsForNewMessage(conversation);
+
     conversation.trigger('newmessage', this);
 
     const isFirstRun = false;
@@ -2389,6 +2364,38 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
     }
   }
 
+  private async handleAttachmentDownloadsForNewMessage(
+    conversation: ConversationModel
+  ) {
+    const idLog = `handleAttachmentDownloadsForNewMessage/${conversation.idForLogging()} ${this.idForLogging()}`;
+
+    // Only queue attachments for downloads if this is a story (with additional logic), or
+    // if it's either an outgoing message or we've accepted the conversation
+    let shouldDownloadNow = false;
+    const attachments = this.get('attachments') || [];
+    const reduxState = window.reduxStore.getState();
+
+    if (isStory(this.attributes)) {
+      shouldDownloadNow = await shouldDownloadStory(conversation.attributes);
+    } else {
+      const isVisualMediaAndUserInCall =
+        isInCall(reduxState) && (isImage(attachments) || isVideo(attachments));
+
+      shouldDownloadNow =
+        this.hasAttachmentDownloads() &&
+        (conversation.getAccepted() || isOutgoing(this.attributes)) &&
+        !isVisualMediaAndUserInCall;
+    }
+
+    if (shouldDownloadNow) {
+      if (shouldUseAttachmentDownloadQueue()) {
+        addToAttachmentDownloadQueue(idLog, this);
+      } else {
+        await this.queueAttachmentDownloads();
+      }
+    }
+  }
+
   // This function is called twice - once from handleDataMessage, and then again from
   //    saveAndNotify, a function called at the end of handleDataMessage as a cleanup for
   //    any missed out-of-order events.
diff --git a/ts/services/backups/import.ts b/ts/services/backups/import.ts
index c8747e1bb0af..499a3150f418 100644
--- a/ts/services/backups/import.ts
+++ b/ts/services/backups/import.ts
@@ -96,6 +96,7 @@ export class BackupImportStream extends Writable {
         forceSave: true,
         ourAci,
       });
+      // TODO (DESKTOP-6845): after we save messages, queue their attachment downloads
     },
   });
   private ourConversation?: ConversationAttributesType;
@@ -626,6 +627,7 @@ export class BackupImportStream extends Writable {
   ): Partial<MessageAttributesType> {
     return {
       body: data.text?.body ?? '',
+      // TODO (DESKTOP-6845): add attachments
       reactions: data.reactions?.map(
         ({ emoji, authorId, sentTimestamp, receivedTimestamp }) => {
           strictAssert(emoji != null, 'reaction must have an emoji');
diff --git a/ts/sql/Client.ts b/ts/sql/Client.ts
index 02e058e202ab..b9085d4ae68b 100644
--- a/ts/sql/Client.ts
+++ b/ts/sql/Client.ts
@@ -35,7 +35,6 @@ import { ipcInvoke, doShutdown } from './channels';
 import type {
   AdjacentMessagesByConversationOptionsType,
   AllItemsType,
-  AttachmentDownloadJobType,
   ClientInterface,
   ClientExclusiveInterface,
   ClientSearchResultMessageType,
@@ -66,6 +65,7 @@ import { getMessageIdForLogging } from '../util/idForLogging';
 import type { MessageAttributesType } from '../model-types';
 import { incrementMessageCounter } from '../util/incrementMessageCounter';
 import { generateSnippetAroundMention } from '../util/search';
+import type { AttachmentDownloadJobType } from '../types/AttachmentDownload';
 
 const ERASE_SQL_KEY = 'erase-sql-key';
 const ERASE_ATTACHMENTS_KEY = 'erase-attachments';
diff --git a/ts/sql/Interface.ts b/ts/sql/Interface.ts
index 8df6e17cae1c..0023da5f75f7 100644
--- a/ts/sql/Interface.ts
+++ b/ts/sql/Interface.ts
@@ -10,7 +10,6 @@ import type { StoredJob } from '../jobs/types';
 import type { ReactionType, ReactionReadStatus } from '../types/Reactions';
 import type { ConversationColorType, CustomColorType } from '../types/Colors';
 import type { StorageAccessType } from '../types/Storage.d';
-import type { AttachmentType } from '../types/Attachment';
 import type { BytesToStrings } from '../types/Util';
 import type { QualifiedAddressStringType } from '../types/QualifiedAddress';
 import type { StoryDistributionIdString } from '../types/StoryDistributionId';
@@ -31,6 +30,7 @@ import type {
   CallHistoryPagination,
 } from '../types/CallDisposition';
 import type { CallLinkType, CallLinkRestrictions } from '../types/CallLink';
+import type { AttachmentDownloadJobType } from '../types/AttachmentDownload';
 
 export type AdjacentMessagesByConversationOptionsType = Readonly<{
   conversationId: string;
@@ -51,24 +51,6 @@ export type GetNearbyMessageFromDeletedSetOptionsType = Readonly<{
   includeStoryReplies: boolean;
 }>;
 
-export type AttachmentDownloadJobTypeType =
-  | 'long-message'
-  | 'attachment'
-  | 'preview'
-  | 'contact'
-  | 'quote'
-  | 'sticker';
-
-export type AttachmentDownloadJobType = {
-  attachment: AttachmentType;
-  attempts: number;
-  id: string;
-  index: number;
-  messageId: string;
-  pending: number;
-  timestamp: number;
-  type: AttachmentDownloadJobTypeType;
-};
 export type MessageMetricsType = {
   id: string;
   received_at: number;
@@ -741,21 +723,22 @@ export type DataInterface = {
   /** only for testing */
   removeAllUnprocessed: () => Promise<void>;
 
-  getAttachmentDownloadJobById: (
-    id: string
-  ) => Promise<AttachmentDownloadJobType | undefined>;
-  getNextAttachmentDownloadJobs: (
-    limit?: number,
-    options?: { timestamp?: number }
-  ) => Promise<Array<AttachmentDownloadJobType>>;
+  getAttachmentDownloadJob(
+    job: Pick<
+      AttachmentDownloadJobType,
+      'messageId' | 'attachmentType' | 'digest'
+    >
+  ): AttachmentDownloadJobType;
+  getNextAttachmentDownloadJobs: (options: {
+    limit: number;
+    prioritizeMessageIds?: Array<string>;
+    timestamp?: number;
+  }) => Promise<Array<AttachmentDownloadJobType>>;
   saveAttachmentDownloadJob: (job: AttachmentDownloadJobType) => Promise<void>;
-  resetAttachmentDownloadPending: () => Promise<void>;
-  setAttachmentDownloadJobPending: (
-    id: string,
-    pending: boolean
+  resetAttachmentDownloadActive: () => Promise<void>;
+  removeAttachmentDownloadJob: (
+    job: AttachmentDownloadJobType
   ) => Promise<void>;
-  removeAttachmentDownloadJob: (id: string) => Promise<number>;
-  removeAllAttachmentDownloadJobs: () => Promise<number>;
 
   createOrUpdateStickerPack: (pack: StickerPackType) => Promise<void>;
   updateStickerPackStatus: (
diff --git a/ts/sql/Server.ts b/ts/sql/Server.ts
index 050db60d5308..fc2e612e41d9 100644
--- a/ts/sql/Server.ts
+++ b/ts/sql/Server.ts
@@ -88,7 +88,6 @@ import { updateSchema } from './migrations';
 import type {
   AdjacentMessagesByConversationOptionsType,
   StoredAllItemsType,
-  AttachmentDownloadJobType,
   ConversationMetricsType,
   ConversationType,
   DeleteSentProtoRecipientOptionsType,
@@ -173,6 +172,10 @@ import {
   updateCallLinkState,
 } from './server/callLinks';
 import { CallMode } from '../types/Calling';
+import {
+  attachmentDownloadJobSchema,
+  type AttachmentDownloadJobType,
+} from '../types/AttachmentDownload';
 
 type ConversationRow = Readonly<{
   json: string;
@@ -353,13 +356,11 @@ const dataInterface: ServerInterface = {
   removeUnprocessed,
   removeAllUnprocessed,
 
-  getAttachmentDownloadJobById,
+  getAttachmentDownloadJob,
   getNextAttachmentDownloadJobs,
   saveAttachmentDownloadJob,
-  resetAttachmentDownloadPending,
-  setAttachmentDownloadJobPending,
+  resetAttachmentDownloadActive,
   removeAttachmentDownloadJob,
-  removeAllAttachmentDownloadJobs,
 
   createOrUpdateStickerPack,
   updateStickerPackStatus,
@@ -4403,127 +4404,184 @@ async function removeAllUnprocessed(): Promise<void> {
 
 // Attachment Downloads
 
-const ATTACHMENT_DOWNLOADS_TABLE = 'attachment_downloads';
-async function getAttachmentDownloadJobById(
-  id: string
-): Promise<AttachmentDownloadJobType | undefined> {
-  return getById(getReadonlyInstance(), ATTACHMENT_DOWNLOADS_TABLE, id);
+function getAttachmentDownloadJob(
+  job: Pick<
+    AttachmentDownloadJobType,
+    'messageId' | 'attachmentType' | 'digest'
+  >
+): AttachmentDownloadJobType {
+  const db = getReadonlyInstance();
+  const [query, params] = sql`
+    SELECT * FROM attachment_downloads
+    WHERE
+      messageId = ${job.messageId}
+    AND 
+      attachmentType = ${job.attachmentType}
+    AND 
+      digest = ${job.digest};
+  `;
+
+  return db.prepare(query).get(params);
 }
-async function getNextAttachmentDownloadJobs(
-  limit?: number,
-  options: { timestamp?: number } = {}
-): Promise<Array<AttachmentDownloadJobType>> {
+
+async function getNextAttachmentDownloadJobs({
+  limit = 3,
+  prioritizeMessageIds,
+  timestamp = Date.now(),
+  maxLastAttemptForPrioritizedMessages,
+}: {
+  limit: number;
+  prioritizeMessageIds?: Array<string>;
+  timestamp?: number;
+  maxLastAttemptForPrioritizedMessages?: number;
+}): Promise<Array<AttachmentDownloadJobType>> {
   const db = await getWritableInstance();
-  const timestamp =
-    options && options.timestamp ? options.timestamp : Date.now();
 
-  const rows: Array<{ json: string; id: string }> = db
-    .prepare<Query>(
-      `
-      SELECT id, json
-      FROM attachment_downloads
-      WHERE pending = 0 AND timestamp <= $timestamp
-      ORDER BY timestamp DESC
-      LIMIT $limit;
-      `
-    )
-    .all({
-      limit: limit || 3,
-      timestamp,
-    });
+  let priorityJobs = [];
 
-  const INNER_ERROR = 'jsonToObject error';
+  // First, try to get jobs for prioritized messages (e.g. those currently user-visible)
+  if (prioritizeMessageIds?.length) {
+    const [priorityQuery, priorityParams] = sql`
+      SELECT * FROM attachment_downloads
+      -- very few rows will match messageIds, so in this case we want to optimize
+      -- the WHERE clause rather than the ORDER BY
+      INDEXED BY attachment_downloads_active_messageId
+      WHERE
+        active = 0
+      AND
+        -- for priority messages, we want to retry based on the last attempt, rather than retryAfter
+        (lastAttemptTimestamp is NULL OR lastAttemptTimestamp <= ${
+          maxLastAttemptForPrioritizedMessages ?? timestamp - durations.HOUR
+        })
+      AND
+        messageId IN (${sqlJoin(prioritizeMessageIds)})
+      -- for priority messages, let's load them oldest first; this helps, e.g. for stories where we 
+      -- want the oldest one first
+      ORDER BY receivedAt ASC
+      LIMIT ${limit}
+    `;
+    priorityJobs = db.prepare(priorityQuery).all(priorityParams);
+  }
+
+  // Next, get any other jobs, sorted by receivedAt
+  const numJobsRemaining = limit - priorityJobs.length;
+  let standardJobs = [];
+  if (numJobsRemaining > 0) {
+    const [query, params] = sql`
+      SELECT * FROM attachment_downloads
+      WHERE
+        active = 0
+      AND
+        (retryAfter is NULL OR retryAfter <= ${timestamp})
+      ORDER BY receivedAt DESC
+      LIMIT ${numJobsRemaining}
+    `;
+
+    standardJobs = db.prepare(query).all(params);
+  }
+
+  const allJobs = priorityJobs.concat(standardJobs);
+  const INNER_ERROR = 'jsonToObject or SchemaParse error';
   try {
-    return rows.map(row => {
+    return allJobs.map(row => {
       try {
-        return jsonToObject(row.json);
+        return attachmentDownloadJobSchema.parse({
+          ...row,
+          active: Boolean(row.active),
+          attachment: jsonToObject(row.attachmentJson),
+        });
       } catch (error) {
         logger.error(
-          `getNextAttachmentDownloadJobs: Error with job '${row.id}', deleting. ` +
-            `JSON: '${row.json}' ` +
-            `Error: ${Errors.toLogFormat(error)}`
+          `getNextAttachmentDownloadJobs: Error with job for message ${row.messageId}, deleting.`
         );
-        removeAttachmentDownloadJobSync(db, row.id);
-        throw new Error(INNER_ERROR);
+
+        removeAttachmentDownloadJobSync(db, row);
+        throw new Error(error);
       }
     });
   } catch (error) {
     if ('message' in error && error.message === INNER_ERROR) {
-      return getNextAttachmentDownloadJobs(limit, { timestamp });
+      return getNextAttachmentDownloadJobs({
+        limit,
+        prioritizeMessageIds,
+        timestamp,
+        maxLastAttemptForPrioritizedMessages,
+      });
     }
     throw error;
   }
 }
+
 async function saveAttachmentDownloadJob(
   job: AttachmentDownloadJobType
 ): Promise<void> {
   const db = await getWritableInstance();
-  const { id, pending, timestamp } = job;
-  if (!id) {
-    throw new Error(
-      'saveAttachmentDownloadJob: Provided job did not have a truthy id'
-    );
-  }
 
-  db.prepare<Query>(
-    `
+  const [query, params] = sql`
     INSERT OR REPLACE INTO attachment_downloads (
-      id,
-      pending,
-      timestamp,
-      json
-    ) values (
-      $id,
-      $pending,
-      $timestamp,
-      $json
-    )
-    `
-  ).run({
-    id,
-    pending,
-    timestamp,
-    json: objectToJSON(job),
-  });
+      messageId,
+      attachmentType,
+      digest,
+      receivedAt,
+      sentAt,
+      contentType,
+      size,
+      active,
+      attempts,
+      retryAfter,
+      lastAttemptTimestamp,
+      attachmentJson
+    ) VALUES (
+      ${job.messageId},
+      ${job.attachmentType},
+      ${job.digest},
+      ${job.receivedAt},
+      ${job.sentAt},
+      ${job.contentType},
+      ${job.size},
+      ${job.active ? 1 : 0},
+      ${job.attempts},
+      ${job.retryAfter},
+      ${job.lastAttemptTimestamp},
+      ${objectToJSON(job.attachment)}
+    );
+  `;
+  db.prepare(query).run(params);
 }
-async function setAttachmentDownloadJobPending(
-  id: string,
-  pending: boolean
-): Promise<void> {
-  const db = await getWritableInstance();
-  db.prepare<Query>(
-    `
-    UPDATE attachment_downloads
-    SET pending = $pending
-    WHERE id = $id;
-    `
-  ).run({
-    id,
-    pending: pending ? 1 : 0,
-  });
-}
-async function resetAttachmentDownloadPending(): Promise<void> {
+
+async function resetAttachmentDownloadActive(): Promise<void> {
   const db = await getWritableInstance();
   db.prepare<EmptyQuery>(
     `
     UPDATE attachment_downloads
-    SET pending = 0
-    WHERE pending != 0;
+    SET active = 0
+    WHERE active != 0;
     `
   ).run();
 }
-function removeAttachmentDownloadJobSync(db: Database, id: string): number {
-  return removeById(db, ATTACHMENT_DOWNLOADS_TABLE, id);
+
+function removeAttachmentDownloadJobSync(
+  db: Database,
+  job: AttachmentDownloadJobType
+): void {
+  const [query, params] = sql`
+    DELETE FROM attachment_downloads
+    WHERE 
+      messageId = ${job.messageId}
+    AND
+      attachmentType = ${job.attachmentType} 
+    AND 
+      digest = ${job.digest};
+  `;
+
+  db.prepare(query).run(params);
 }
-async function removeAttachmentDownloadJob(id: string): Promise<number> {
+
+async function removeAttachmentDownloadJob(
+  job: AttachmentDownloadJobType
+): Promise<void> {
   const db = await getWritableInstance();
-  return removeAttachmentDownloadJobSync(db, id);
-}
-async function removeAllAttachmentDownloadJobs(): Promise<number> {
-  return removeAllFromTable(
-    await getWritableInstance(),
-    ATTACHMENT_DOWNLOADS_TABLE
-  );
+  return removeAttachmentDownloadJobSync(db, job);
 }
 
 // Stickers
diff --git a/ts/sql/migrations/1040-undownloaded-backed-up-media.ts b/ts/sql/migrations/1040-undownloaded-backed-up-media.ts
new file mode 100644
index 000000000000..77687e3cd0a4
--- /dev/null
+++ b/ts/sql/migrations/1040-undownloaded-backed-up-media.ts
@@ -0,0 +1,208 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+import type { Database } from '@signalapp/better-sqlite3';
+
+import type { LoggerType } from '../../types/Logging';
+import {
+  attachmentDownloadJobSchema,
+  type AttachmentDownloadJobType,
+  type AttachmentDownloadJobTypeType,
+} from '../../types/AttachmentDownload';
+import type { AttachmentType } from '../../types/Attachment';
+import { jsonToObject, objectToJSON, sql } from '../util';
+
+export const version = 1040;
+
+export type LegacyAttachmentDownloadJobType = {
+  attachment: AttachmentType;
+  attempts: number;
+  id: string;
+  index: number;
+  messageId: string;
+  pending: number;
+  timestamp: number;
+  type: AttachmentDownloadJobTypeType;
+};
+
+export function updateToSchemaVersion1040(
+  currentVersion: number,
+  db: Database,
+  logger: LoggerType
+): void {
+  if (currentVersion >= 1040) {
+    return;
+  }
+
+  db.transaction(() => {
+    // 1. Load all existing rows into memory (shouldn't be many)
+    const existingJobs: Array<{
+      id: string | null;
+      timestamp: number | null;
+      pending: number | null;
+      json: string | null;
+    }> = db
+      .prepare(
+        `
+          SELECT id, timestamp, pending, json from attachment_downloads
+        `
+      )
+      .all();
+    logger.info(
+      `updateToSchemaVersion1040: loaded ${existingJobs.length} existing jobs`
+    );
+
+    // 2. Create new temp table, with a couple new columns and stricter typing
+    db.exec(`
+        CREATE TABLE tmp_attachment_downloads (
+          messageId TEXT NOT NULL REFERENCES messages(id) ON DELETE CASCADE,
+          attachmentType TEXT NOT NULL,
+          digest TEXT NOT NULL,
+          receivedAt INTEGER NOT NULL,
+          sentAt INTEGER NOT NULL,
+          contentType TEXT NOT NULL,
+          size INTEGER NOT NULL,
+          attachmentJson TEXT NOT NULL,
+          active INTEGER NOT NULL,
+          attempts INTEGER NOT NULL,
+          retryAfter INTEGER,
+          lastAttemptTimestamp INTEGER,
+          
+          PRIMARY KEY (messageId, attachmentType, digest)
+        ) STRICT;
+    `);
+
+    // 3. Drop existing table
+    db.exec('DROP TABLE attachment_downloads;');
+
+    // 4. Rename temp table
+    db.exec(
+      'ALTER TABLE tmp_attachment_downloads RENAME TO attachment_downloads;'
+    );
+
+    // 5. Add new index on active & receivedAt. For most queries when there are lots of
+    //    jobs (like during backup restore), many jobs will match the the WHERE clause, so
+    //    the ORDER BY on receivedAt is probably the most expensive part.
+    db.exec(`      
+      CREATE INDEX attachment_downloads_active_receivedAt
+        ON attachment_downloads (
+          active, receivedAt
+      );
+    `);
+
+    // 6. Add new index on active & messageId. In order to prioritize visible messages,
+    //    we'll also query for rows with a matching messageId. For these, the messageId
+    //    matching is likely going to be the most expensive part.
+    db.exec(` 
+      CREATE INDEX attachment_downloads_active_messageId
+        ON attachment_downloads (
+          active, messageId
+      );
+    `);
+
+    // 7. Add new index just on messageId, for the ON DELETE CASCADE foreign key
+    //    constraint
+    db.exec(` 
+      CREATE INDEX attachment_downloads_messageId
+        ON attachment_downloads (
+          messageId
+      );
+    `);
+
+    // 8. Rewrite old rows to match new schema
+    const rowsToTransfer: Array<AttachmentDownloadJobType> = [];
+
+    for (const existingJob of existingJobs) {
+      try {
+        // Type this as partial in case there is missing data
+        const existingJobData: Partial<LegacyAttachmentDownloadJobType> =
+          jsonToObject(existingJob.json ?? '');
+
+        const updatedJob: Partial<AttachmentDownloadJobType> = {
+          messageId: existingJobData.messageId,
+          attachmentType: existingJobData.type,
+          attachment: existingJobData.attachment,
+          // The existing timestamp column works reasonably well in place of
+          // actually retrieving the message's receivedAt
+          receivedAt: existingJobData.timestamp ?? Date.now(),
+          sentAt: existingJobData.timestamp ?? Date.now(),
+          digest: existingJobData.attachment?.digest,
+          contentType: existingJobData.attachment?.contentType,
+          size: existingJobData.attachment?.size,
+          active: false, // all jobs are inactive on app start
+          attempts: existingJobData.attempts ?? 0,
+          retryAfter: null,
+          lastAttemptTimestamp: null,
+        };
+
+        const parsed = attachmentDownloadJobSchema.parse(updatedJob);
+
+        rowsToTransfer.push(parsed as AttachmentDownloadJobType);
+      } catch {
+        logger.warn(
+          `updateToSchemaVersion1040: unable to transfer job ${existingJob.id} to new table; invalid data`
+        );
+      }
+    }
+
+    let numTransferred = 0;
+    if (rowsToTransfer.length) {
+      logger.info(
+        `updateToSchemaVersion1040: transferring ${rowsToTransfer.length} rows`
+      );
+      for (const row of rowsToTransfer) {
+        const [insertQuery, insertParams] = sql`
+          INSERT INTO attachment_downloads
+            (
+              messageId,
+              attachmentType,
+              receivedAt, 
+              sentAt,
+              digest,
+              contentType,
+              size,
+              attachmentJson,
+              active, 
+              attempts,
+              retryAfter,
+              lastAttemptTimestamp
+            )
+          VALUES
+            (
+              ${row.messageId},
+              ${row.attachmentType},
+              ${row.receivedAt},
+              ${row.sentAt},
+              ${row.digest},
+              ${row.contentType},
+              ${row.size},
+              ${objectToJSON(row.attachment)},
+              ${row.active ? 1 : 0}, 
+              ${row.attempts},
+              ${row.retryAfter},
+              ${row.lastAttemptTimestamp}
+            );
+        `;
+        try {
+          db.prepare(insertQuery).run(insertParams);
+          numTransferred += 1;
+        } catch (error) {
+          logger.error(
+            'updateToSchemaVersion1040: error when transferring row',
+            error
+          );
+        }
+      }
+    }
+
+    logger.info(
+      `updateToSchemaVersion1040: transferred ${numTransferred} rows, removed ${
+        existingJobs.length - numTransferred
+      }`
+    );
+  })();
+
+  db.pragma('user_version = 1040');
+
+  logger.info('updateToSchemaVersion1040: success!');
+}
diff --git a/ts/sql/migrations/index.ts b/ts/sql/migrations/index.ts
index e37c5bec503d..06514b14e125 100644
--- a/ts/sql/migrations/index.ts
+++ b/ts/sql/migrations/index.ts
@@ -78,10 +78,11 @@ import { updateToSchemaVersion990 } from './990-phone-number-sharing';
 import { updateToSchemaVersion1000 } from './1000-mark-unread-call-history-messages-as-unseen';
 import { updateToSchemaVersion1010 } from './1010-call-links-table';
 import { updateToSchemaVersion1020 } from './1020-self-merges';
+import { updateToSchemaVersion1030 } from './1030-unblock-event';
 import {
+  updateToSchemaVersion1040,
   version as MAX_VERSION,
-  updateToSchemaVersion1030,
-} from './1030-unblock-event';
+} from './1040-undownloaded-backed-up-media';
 
 function updateToSchemaVersion1(
   currentVersion: number,
@@ -2027,6 +2028,7 @@ export const SCHEMA_VERSIONS = [
   updateToSchemaVersion1010,
   updateToSchemaVersion1020,
   updateToSchemaVersion1030,
+  updateToSchemaVersion1040,
 ];
 
 export class DBVersionFromFutureError extends Error {
diff --git a/ts/state/ducks/conversations.ts b/ts/state/ducks/conversations.ts
index 8a03a221e3a2..47fd0a56b335 100644
--- a/ts/state/ducks/conversations.ts
+++ b/ts/state/ducks/conversations.ts
@@ -183,6 +183,7 @@ import { getAddedByForOurPendingInvitation } from '../../util/getAddedByForOurPe
 import { getConversationIdForLogging } from '../../util/idForLogging';
 import { singleProtoJobQueue } from '../../jobs/singleProtoJobQueue';
 import MessageSender from '../../textsecure/SendMessage';
+import { AttachmentDownloadUrgency } from '../../jobs/AttachmentDownloadManager';
 
 // State
 
@@ -2174,7 +2175,9 @@ function kickOffAttachmentDownload(
         `kickOffAttachmentDownload: Message ${options.messageId} missing!`
       );
     }
-    const didUpdateValues = await message.queueAttachmentDownloads();
+    const didUpdateValues = await message.queueAttachmentDownloads(
+      AttachmentDownloadUrgency.IMMEDIATE
+    );
 
     if (didUpdateValues) {
       drop(
diff --git a/ts/state/ducks/stories.ts b/ts/state/ducks/stories.ts
index ecbb9b45074d..f36371051a67 100644
--- a/ts/state/ducks/stories.ts
+++ b/ts/state/ducks/stories.ts
@@ -512,10 +512,9 @@ function queueStoryDownload(
       return;
     }
 
-    // isDownloading checks for the downloadJobId which is set by
-    // queueAttachmentDownloads but we optimistically set story.startedDownload
-    // in redux to prevent race conditions from queuing up multiple attachment
-    // downloads before the attachment save takes place.
+    // isDownloading checks if the download is pending but we optimistically set
+    // story.startedDownload in redux to prevent race conditions from queuing up multiple
+    // attachment downloads before the attachment save takes place.
     if (isDownloading(attachment) || story.startedDownload) {
       return;
     }
diff --git a/ts/state/smart/Timeline.tsx b/ts/state/smart/Timeline.tsx
index 4f0621d2ad0f..b30403a18e54 100644
--- a/ts/state/smart/Timeline.tsx
+++ b/ts/state/smart/Timeline.tsx
@@ -42,6 +42,7 @@ import { SmartHeroRow } from './HeroRow';
 import { SmartMiniPlayer } from './MiniPlayer';
 import { SmartTimelineItem, type SmartTimelineItemProps } from './TimelineItem';
 import { SmartTypingBubble } from './TypingBubble';
+import { AttachmentDownloadManager } from '../../jobs/AttachmentDownloadManager';
 
 type ExternalProps = {
   id: string;
@@ -266,6 +267,9 @@ export const SmartTimeline = memo(function SmartTimeline({
       markMessageRead={markMessageRead}
       messageChangeCounter={messageChangeCounter}
       messageLoadingState={messageLoadingState}
+      updateVisibleMessages={
+        AttachmentDownloadManager.updateVisibleTimelineMessages
+      }
       oldestUnseenIndex={oldestUnseenIndex}
       peekGroupCallForTheFirstTime={peekGroupCallForTheFirstTime}
       peekGroupCallIfItHasMembers={peekGroupCallIfItHasMembers}
diff --git a/ts/test-both/util/exponentialBackoff_test.ts b/ts/test-both/util/exponentialBackoff_test.ts
index 674605262e2e..778df2567991 100644
--- a/ts/test-both/util/exponentialBackoff_test.ts
+++ b/ts/test-both/util/exponentialBackoff_test.ts
@@ -25,6 +25,21 @@ describe('exponential backoff utilities', () => {
         assert.strictEqual(exponentialBackoffSleepTime(attempt), maximum);
       }
     });
+
+    it('respects custom variables', () => {
+      const options = {
+        maxBackoffTime: 10000,
+        multiplier: 2,
+        firstBackoffTime: 1000,
+      };
+      assert.strictEqual(exponentialBackoffSleepTime(1, options), 0);
+      assert.strictEqual(exponentialBackoffSleepTime(2, options), 1000);
+      assert.strictEqual(exponentialBackoffSleepTime(3, options), 2000);
+      assert.strictEqual(exponentialBackoffSleepTime(4, options), 4000);
+      assert.strictEqual(exponentialBackoffSleepTime(5, options), 8000);
+      assert.strictEqual(exponentialBackoffSleepTime(6, options), 10000);
+      assert.strictEqual(exponentialBackoffSleepTime(7, options), 10000);
+    });
   });
 
   describe('exponentialBackoffMaxAttempts', () => {
diff --git a/ts/test-electron/services/AttachmentDownloadManager_test.ts b/ts/test-electron/services/AttachmentDownloadManager_test.ts
new file mode 100644
index 000000000000..bd3ba57af59e
--- /dev/null
+++ b/ts/test-electron/services/AttachmentDownloadManager_test.ts
@@ -0,0 +1,367 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+
+/* eslint-disable more/no-then */
+/* eslint-disable @typescript-eslint/no-floating-promises */
+import * as sinon from 'sinon';
+import { assert } from 'chai';
+import * as MIME from '../../types/MIME';
+
+import {
+  AttachmentDownloadManager,
+  AttachmentDownloadUrgency,
+  type NewAttachmentDownloadJobType,
+} from '../../jobs/AttachmentDownloadManager';
+import type { AttachmentDownloadJobType } from '../../types/AttachmentDownload';
+import dataInterface from '../../sql/Client';
+import { HOUR, MINUTE, SECOND } from '../../util/durations';
+import { type AciString } from '../../types/ServiceId';
+
+describe('AttachmentDownloadManager', () => {
+  let downloadManager: AttachmentDownloadManager | undefined;
+  let runJob: sinon.SinonStub;
+  let sandbox: sinon.SinonSandbox;
+  let clock: sinon.SinonFakeTimers;
+  let isInCall: sinon.SinonStub;
+
+  function composeJob({
+    messageId,
+    receivedAt,
+  }: Pick<
+    NewAttachmentDownloadJobType,
+    'messageId' | 'receivedAt'
+  >): AttachmentDownloadJobType {
+    const digest = `digestFor${messageId}`;
+    const size = 128;
+    const contentType = MIME.IMAGE_PNG;
+    return {
+      messageId,
+      receivedAt,
+      sentAt: receivedAt,
+      attachmentType: 'attachment',
+      digest,
+      size,
+      contentType,
+      active: false,
+      attempts: 0,
+      retryAfter: null,
+      lastAttemptTimestamp: null,
+      attachment: {
+        contentType,
+        size,
+        digest: `digestFor${messageId}`,
+      },
+    };
+  }
+
+  beforeEach(async () => {
+    await dataInterface.removeAll();
+
+    sandbox = sinon.createSandbox();
+    clock = sinon.useFakeTimers();
+
+    isInCall = sinon.stub().returns(false);
+    runJob = sinon.stub().callsFake(async () => {
+      return new Promise<{ status: 'finished' | 'retry' }>(resolve => {
+        Promise.resolve().then(() => {
+          resolve({ status: 'finished' });
+        });
+      });
+    });
+
+    downloadManager = new AttachmentDownloadManager({
+      ...AttachmentDownloadManager.defaultParams,
+      isInCall,
+      runJob,
+    });
+  });
+
+  afterEach(async () => {
+    sandbox.restore();
+    clock.restore();
+    await downloadManager?.stop();
+  });
+
+  async function addJob(
+    job: AttachmentDownloadJobType,
+    urgency: AttachmentDownloadUrgency
+  ) {
+    // Save message first to satisfy foreign key constraint
+    await dataInterface.saveMessage(
+      {
+        id: job.messageId,
+        type: 'incoming',
+        sent_at: job.sentAt,
+        timestamp: job.sentAt,
+        received_at: job.receivedAt + 1,
+        conversationId: 'convoId',
+      },
+      {
+        ourAci: 'ourAci' as AciString,
+        forceSave: true,
+      }
+    );
+    await downloadManager?.addJob({
+      ...job,
+      urgency,
+    });
+  }
+  async function addJobs(
+    num: number
+  ): Promise<Array<AttachmentDownloadJobType>> {
+    const jobs = new Array(num)
+      .fill(null)
+      .map((_, idx) =>
+        composeJob({ messageId: `message-${idx}`, receivedAt: idx })
+      );
+    for (const job of jobs) {
+      // eslint-disable-next-line no-await-in-loop
+      await addJob(job, AttachmentDownloadUrgency.STANDARD);
+    }
+    return jobs;
+  }
+
+  function waitForJobToBeStarted(job: AttachmentDownloadJobType) {
+    return downloadManager?.waitForJobToBeStarted(job);
+  }
+
+  function waitForJobToBeCompleted(job: AttachmentDownloadJobType) {
+    return downloadManager?.waitForJobToBeCompleted(job);
+  }
+
+  function assertRunJobCalledWith(jobs: Array<AttachmentDownloadJobType>) {
+    return assert.strictEqual(
+      JSON.stringify(
+        runJob
+          .getCalls()
+          .map(
+            call =>
+              `${call.args[0].messageId}${call.args[0].attachmentType}.${call.args[0].digest}`
+          )
+      ),
+      JSON.stringify(
+        jobs.map(job => `${job.messageId}${job.attachmentType}.${job.digest}`)
+      )
+    );
+  }
+
+  async function advanceTime(ms: number) {
+    // When advancing the timers, we want to make sure any DB operations are completed
+    // first. In cases like maybeStartJobs where we prevent re-entrancy, without this,
+    // prior (unfinished) invocations can prevent subsequent calls after the clock is
+    // ticked forward and make tests unreliable
+    await dataInterface.getAllItems();
+    await clock.tickAsync(ms);
+  }
+
+  function getPromisesForAttempts(
+    job: AttachmentDownloadJobType,
+    attempts: number
+  ) {
+    return new Array(attempts).fill(null).map((_, idx) => {
+      return {
+        started: waitForJobToBeStarted({ ...job, attempts: idx }),
+        completed: waitForJobToBeCompleted({ ...job, attempts: idx }),
+      };
+    });
+  }
+
+  it('runs 3 jobs at a time in descending receivedAt order', async () => {
+    const jobs = await addJobs(5);
+    // Confirm they are saved to DB
+    const allJobs = await dataInterface.getNextAttachmentDownloadJobs({
+      limit: 100,
+    });
+
+    assert.strictEqual(allJobs.length, 5);
+    assert.strictEqual(
+      JSON.stringify(allJobs.map(job => job.messageId)),
+      JSON.stringify([
+        'message-4',
+        'message-3',
+        'message-2',
+        'message-1',
+        'message-0',
+      ])
+    );
+
+    await downloadManager?.start();
+    await waitForJobToBeStarted(jobs[2]);
+
+    assert.strictEqual(runJob.callCount, 3);
+    assertRunJobCalledWith([jobs[4], jobs[3], jobs[2]]);
+
+    await waitForJobToBeStarted(jobs[0]);
+    assert.strictEqual(runJob.callCount, 5);
+    assertRunJobCalledWith([jobs[4], jobs[3], jobs[2], jobs[1], jobs[0]]);
+  });
+
+  it('runs a job immediately if urgency is IMMEDIATE', async () => {
+    const jobs = await addJobs(6);
+    await downloadManager?.start();
+
+    const urgentJobForOldMessage = composeJob({
+      messageId: 'message-urgent',
+      receivedAt: 0,
+    });
+
+    await addJob(urgentJobForOldMessage, AttachmentDownloadUrgency.IMMEDIATE);
+
+    await waitForJobToBeStarted(urgentJobForOldMessage);
+
+    assert.strictEqual(runJob.callCount, 4);
+    assertRunJobCalledWith([jobs[5], jobs[4], jobs[3], urgentJobForOldMessage]);
+
+    await waitForJobToBeStarted(jobs[0]);
+    assert.strictEqual(runJob.callCount, 7);
+    assertRunJobCalledWith([
+      jobs[5],
+      jobs[4],
+      jobs[3],
+      urgentJobForOldMessage,
+      jobs[2],
+      jobs[1],
+      jobs[0],
+    ]);
+  });
+
+  it('prefers jobs for visible messages', async () => {
+    const jobs = await addJobs(5);
+
+    downloadManager?.updateVisibleTimelineMessages(['message-0', 'message-1']);
+
+    await downloadManager?.start();
+
+    await waitForJobToBeStarted(jobs[4]);
+    assert.strictEqual(runJob.callCount, 3);
+    assertRunJobCalledWith([jobs[0], jobs[1], jobs[4]]);
+
+    await waitForJobToBeStarted(jobs[2]);
+    assert.strictEqual(runJob.callCount, 5);
+    assertRunJobCalledWith([jobs[0], jobs[1], jobs[4], jobs[3], jobs[2]]);
+  });
+
+  it("does not start a job if we're in a call", async () => {
+    const jobs = await addJobs(5);
+
+    isInCall.callsFake(() => true);
+
+    await downloadManager?.start();
+    await advanceTime(2 * MINUTE);
+    assert.strictEqual(runJob.callCount, 0);
+
+    isInCall.callsFake(() => false);
+
+    await advanceTime(2 * MINUTE);
+    await waitForJobToBeStarted(jobs[0]);
+    assert.strictEqual(runJob.callCount, 5);
+  });
+
+  it('handles retries for failed', async () => {
+    const jobs = await addJobs(2);
+    const job0Attempts = getPromisesForAttempts(jobs[0], 1);
+    const job1Attempts = getPromisesForAttempts(jobs[1], 5);
+
+    runJob.callsFake(async (job: AttachmentDownloadJobType) => {
+      return new Promise<{ status: 'finished' | 'retry' }>(resolve => {
+        Promise.resolve().then(() => {
+          if (job.messageId === jobs[0].messageId) {
+            resolve({ status: 'finished' });
+          } else {
+            resolve({ status: 'retry' });
+          }
+        });
+      });
+    });
+
+    await downloadManager?.start();
+
+    await job0Attempts[0].completed;
+    assert.strictEqual(runJob.callCount, 2);
+    assertRunJobCalledWith([jobs[1], jobs[0]]);
+
+    const retriedJob = await dataInterface.getAttachmentDownloadJob(jobs[1]);
+    const finishedJob = await dataInterface.getAttachmentDownloadJob(jobs[0]);
+
+    assert.isUndefined(finishedJob);
+    assert.strictEqual(retriedJob?.attempts, 1);
+    assert.isNumber(retriedJob?.retryAfter);
+
+    await advanceTime(30 * SECOND);
+    await job1Attempts[1].completed;
+    assert.strictEqual(runJob.callCount, 3);
+
+    await advanceTime(5 * MINUTE);
+    await job1Attempts[2].completed;
+    assert.strictEqual(runJob.callCount, 4);
+
+    await advanceTime(50 * MINUTE);
+    await job1Attempts[3].completed;
+    assert.strictEqual(runJob.callCount, 5);
+
+    await advanceTime(6 * HOUR);
+    await job1Attempts[4].completed;
+    assert.strictEqual(runJob.callCount, 6);
+    assertRunJobCalledWith([
+      jobs[1],
+      jobs[0],
+      jobs[1],
+      jobs[1],
+      jobs[1],
+      jobs[1],
+    ]);
+
+    // Ensure it's been removed after completed
+    assert.isUndefined(await dataInterface.getAttachmentDownloadJob(jobs[1]));
+  });
+
+  it('will reset attempts if addJob is called again', async () => {
+    const jobs = await addJobs(1);
+    runJob.callsFake(async () => {
+      return new Promise<{ status: 'finished' | 'retry' }>(resolve => {
+        Promise.resolve().then(() => {
+          resolve({ status: 'retry' });
+        });
+      });
+    });
+
+    let attempts = getPromisesForAttempts(jobs[0], 4);
+    await downloadManager?.start();
+
+    await attempts[0].completed;
+    assert.strictEqual(runJob.callCount, 1);
+
+    await advanceTime(30 * SECOND);
+    await attempts[1].completed;
+    assert.strictEqual(runJob.callCount, 2);
+
+    await advanceTime(5 * MINUTE);
+    await attempts[2].completed;
+    assert.strictEqual(runJob.callCount, 3);
+
+    // add the same job again and it should retry ASAP and reset attempts
+    attempts = getPromisesForAttempts(jobs[0], 4);
+    await downloadManager?.addJob(jobs[0]);
+    await attempts[0].completed;
+    assert.strictEqual(runJob.callCount, 4);
+
+    await advanceTime(30 * SECOND);
+    await attempts[1].completed;
+    assert.strictEqual(runJob.callCount, 5);
+
+    await advanceTime(5 * MINUTE);
+    await attempts[2].completed;
+    assert.strictEqual(runJob.callCount, 6);
+
+    await advanceTime(50 * MINUTE);
+    await attempts[3].completed;
+    assert.strictEqual(runJob.callCount, 7);
+
+    await advanceTime(6 * HOUR);
+    await attempts[3].completed;
+    assert.strictEqual(runJob.callCount, 8);
+
+    // Ensure it's been removed
+    assert.isUndefined(await dataInterface.getAttachmentDownloadJob(jobs[0]));
+  });
+});
diff --git a/ts/test-node/sql/migration_1040_test.ts b/ts/test-node/sql/migration_1040_test.ts
new file mode 100644
index 000000000000..71d2d8aa6a75
--- /dev/null
+++ b/ts/test-node/sql/migration_1040_test.ts
@@ -0,0 +1,484 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+import { omit } from 'lodash';
+import { assert } from 'chai';
+import type { Database } from '@signalapp/better-sqlite3';
+import SQL from '@signalapp/better-sqlite3';
+
+import { jsonToObject, objectToJSON, sql, sqlJoin } from '../../sql/util';
+import { updateToVersion } from './helpers';
+import type { LegacyAttachmentDownloadJobType } from '../../sql/migrations/1040-undownloaded-backed-up-media';
+import type { AttachmentType } from '../../types/Attachment';
+import type { AttachmentDownloadJobType } from '../../types/AttachmentDownload';
+import { IMAGE_JPEG } from '../../types/MIME';
+
+function getAttachmentDownloadJobs(db: Database) {
+  const [query] = sql`
+    SELECT * FROM attachment_downloads ORDER BY receivedAt DESC;
+  `;
+
+  return db
+    .prepare(query)
+    .all()
+    .map(job => ({
+      ...omit(job, 'attachmentJson'),
+      attachment: jsonToObject(job.attachmentJson),
+    }));
+}
+
+type UnflattenedAttachmentDownloadJobType = Omit<
+  AttachmentDownloadJobType,
+  'digest' | 'contentType' | 'size'
+>;
+function insertNewJob(
+  db: Database,
+  job: UnflattenedAttachmentDownloadJobType,
+  addMessageFirst: boolean = true
+): void {
+  if (addMessageFirst) {
+    try {
+      db.prepare('INSERT INTO messages (id) VALUES ($id)').run({
+        id: job.messageId,
+      });
+    } catch (e) {
+      // pass; message has already been inserted
+    }
+  }
+  const [query, params] = sql`
+  INSERT INTO attachment_downloads
+    (
+      messageId,
+      attachmentType,
+      attachmentJson,
+      digest,
+      contentType,
+      size,
+      receivedAt, 
+      sentAt,
+      active, 
+      attempts,
+      retryAfter,
+      lastAttemptTimestamp
+    )
+  VALUES
+    (
+      ${job.messageId},
+      ${job.attachmentType},
+      ${objectToJSON(job.attachment)},
+      ${job.attachment.digest},
+      ${job.attachment.contentType},
+      ${job.attachment.size},
+      ${job.receivedAt},
+      ${job.sentAt},
+      ${job.active ? 1 : 0},
+      ${job.attempts},
+      ${job.retryAfter},
+      ${job.lastAttemptTimestamp}
+    );
+`;
+
+  db.prepare(query).run(params);
+}
+
+describe('SQL/updateToSchemaVersion1040', () => {
+  describe('Storing of new attachment jobs', () => {
+    let db: Database;
+
+    beforeEach(() => {
+      db = new SQL(':memory:');
+      updateToVersion(db, 1040);
+    });
+
+    afterEach(() => {
+      db.close();
+    });
+
+    it('allows storing of new backup attachment jobs', () => {
+      insertNewJob(db, {
+        messageId: 'message1',
+        attachmentType: 'attachment',
+        attachment: {
+          digest: 'digest1',
+          contentType: IMAGE_JPEG,
+          size: 128,
+        },
+        receivedAt: 1970,
+        sentAt: 2070,
+        active: false,
+        retryAfter: null,
+        attempts: 0,
+        lastAttemptTimestamp: null,
+      });
+
+      insertNewJob(db, {
+        messageId: 'message2',
+        attachmentType: 'attachment',
+        attachment: {
+          digest: 'digest2',
+          contentType: IMAGE_JPEG,
+          size: 128,
+        },
+        receivedAt: 1971,
+        sentAt: 2071,
+        active: false,
+        retryAfter: 1204,
+        attempts: 0,
+        lastAttemptTimestamp: 1004,
+      });
+
+      const attachments = getAttachmentDownloadJobs(db);
+      assert.strictEqual(attachments.length, 2);
+      assert.deepEqual(attachments, [
+        {
+          messageId: 'message2',
+          attachmentType: 'attachment',
+          digest: 'digest2',
+          contentType: IMAGE_JPEG,
+          size: 128,
+          receivedAt: 1971,
+          sentAt: 2071,
+          active: 0,
+          retryAfter: 1204,
+          attempts: 0,
+          lastAttemptTimestamp: 1004,
+          attachment: {
+            digest: 'digest2',
+            contentType: IMAGE_JPEG,
+            size: 128,
+          },
+        },
+        {
+          messageId: 'message1',
+          attachmentType: 'attachment',
+          digest: 'digest1',
+          contentType: IMAGE_JPEG,
+          size: 128,
+          receivedAt: 1970,
+          sentAt: 2070,
+          active: 0,
+          retryAfter: null,
+          attempts: 0,
+          lastAttemptTimestamp: null,
+          attachment: {
+            digest: 'digest1',
+            contentType: IMAGE_JPEG,
+            size: 128,
+          },
+        },
+      ]);
+    });
+
+    it('Respects primary key constraint', () => {
+      const job: UnflattenedAttachmentDownloadJobType = {
+        messageId: 'message1',
+        attachmentType: 'attachment',
+        attachment: {
+          digest: 'digest1',
+          contentType: IMAGE_JPEG,
+          size: 128,
+        },
+        receivedAt: 1970,
+        sentAt: 2070,
+        active: false,
+        retryAfter: null,
+        attempts: 0,
+        lastAttemptTimestamp: null,
+      };
+      insertNewJob(db, job);
+      assert.throws(() => {
+        insertNewJob(db, { ...job, attempts: 1 });
+      });
+
+      const attachments = getAttachmentDownloadJobs(db);
+      assert.strictEqual(attachments.length, 1);
+      assert.strictEqual(attachments[0].attempts, 0);
+    });
+
+    it('uses indices searching for next job', () => {
+      const now = Date.now();
+
+      const job: UnflattenedAttachmentDownloadJobType = {
+        messageId: 'message1',
+        attachmentType: 'attachment',
+        attachment: {
+          digest: 'digest1',
+          contentType: IMAGE_JPEG,
+          size: 128,
+        },
+        receivedAt: 101,
+        sentAt: 101,
+        attempts: 0,
+        active: false,
+        retryAfter: null,
+        lastAttemptTimestamp: null,
+      };
+      insertNewJob(db, job);
+      insertNewJob(db, {
+        ...job,
+        messageId: 'message2',
+        receivedAt: 102,
+        sentAt: 102,
+        retryAfter: now + 1,
+        lastAttemptTimestamp: now - 10,
+      });
+      insertNewJob(db, {
+        ...job,
+        messageId: 'message3',
+        active: true,
+        receivedAt: 103,
+        sentAt: 103,
+      });
+      insertNewJob(db, {
+        ...job,
+        messageId: 'message4',
+        attachmentType: 'contact',
+        receivedAt: 104,
+        sentAt: 104,
+        retryAfter: now,
+        lastAttemptTimestamp: now - 1000,
+      });
+
+      {
+        const [query, params] = sql`
+          SELECT * FROM attachment_downloads
+          WHERE
+            active = 0
+          AND
+            (retryAfter is NULL OR retryAfter <= ${now})
+          ORDER BY receivedAt DESC
+          LIMIT 5
+        `;
+
+        const result = db.prepare(query).all(params);
+        assert.strictEqual(result.length, 2);
+        assert.deepStrictEqual(
+          result.map(res => res.messageId),
+          ['message4', 'message1']
+        );
+
+        const details = db
+          .prepare(`EXPLAIN QUERY PLAN ${query}`)
+          .all(params)
+          .map(step => step.detail)
+          .join(', ');
+        assert.include(
+          details,
+          'USING INDEX attachment_downloads_active_receivedAt'
+        );
+        assert.notInclude(details, 'TEMP B-TREE');
+        assert.notInclude(details, 'SCAN');
+      }
+      {
+        const messageIds = ['message1', 'message2', 'message4'];
+        const [query, params] = sql`
+        SELECT * FROM attachment_downloads
+        INDEXED BY attachment_downloads_active_messageId
+        WHERE
+          active = 0
+        AND
+          (lastAttemptTimestamp is NULL OR lastAttemptTimestamp <= ${now - 100})
+        AND
+          messageId IN (${sqlJoin(messageIds)})
+        ORDER BY receivedAt ASC
+        LIMIT 5
+        `;
+
+        const result = db.prepare(query).all(params);
+        assert.strictEqual(result.length, 2);
+        assert.deepStrictEqual(
+          result.map(res => res.messageId),
+          ['message1', 'message4']
+        );
+        const details = db
+          .prepare(`EXPLAIN QUERY PLAN ${query}`)
+          .all(params)
+          .map(step => step.detail)
+          .join(', ');
+
+        // This query _will_ use a temp b-tree for ordering, but the number of rows
+        // should be quite low.
+        assert.include(
+          details,
+          'USING INDEX attachment_downloads_active_messageId'
+        );
+      }
+    });
+
+    it('respects foreign key constraint on messageId', () => {
+      const job: AttachmentDownloadJobType = {
+        messageId: 'message1',
+        attachmentType: 'attachment',
+        attachment: {
+          digest: 'digest1',
+          contentType: IMAGE_JPEG,
+          size: 128,
+        },
+        receivedAt: 1970,
+        digest: 'digest1',
+        contentType: IMAGE_JPEG,
+        size: 128,
+        sentAt: 2070,
+        active: false,
+        retryAfter: null,
+        attempts: 0,
+        lastAttemptTimestamp: null,
+      };
+      // throws if we don't add the message first
+      assert.throws(() => insertNewJob(db, job, false));
+      insertNewJob(db, job, true);
+
+      assert.strictEqual(getAttachmentDownloadJobs(db).length, 1);
+
+      // Deletes the job when the message is deleted
+      db.prepare('DELETE FROM messages WHERE id = $id').run({
+        id: job.messageId,
+      });
+      assert.strictEqual(getAttachmentDownloadJobs(db).length, 0);
+    });
+  });
+
+  describe('existing jobs are transferred', () => {
+    let db: Database;
+
+    beforeEach(() => {
+      db = new SQL(':memory:');
+      updateToVersion(db, 1030);
+    });
+
+    afterEach(() => {
+      db.close();
+    });
+
+    it('existing rows are retained; invalid existing rows are removed', () => {
+      insertLegacyJob(db, {
+        id: 'id-1',
+        messageId: 'message-1',
+        timestamp: 1000,
+        attachment: {
+          size: 100,
+          contentType: 'image/png',
+          digest: 'digest1',
+          cdnKey: 'key1',
+        } as AttachmentType,
+        pending: 0,
+        index: 0,
+        type: 'attachment',
+      });
+      insertLegacyJob(db, {
+        id: 'invalid-1',
+      });
+      insertLegacyJob(db, {
+        id: 'id-2',
+        messageId: 'message-2',
+        timestamp: 1001,
+        attachment: {
+          size: 100,
+          contentType: 'image/jpeg',
+          digest: 'digest2',
+          cdnKey: 'key2',
+        } as AttachmentType,
+        pending: 1,
+        index: 2,
+        type: 'attachment',
+        attempts: 1,
+      });
+      insertLegacyJob(db, {
+        id: 'invalid-2',
+        timestamp: 1000,
+        attachment: { size: 100, contentType: 'image/jpeg' } as AttachmentType,
+        pending: 0,
+        index: 0,
+        type: 'attachment',
+      });
+      insertLegacyJob(db, {
+        id: 'invalid-3-no-content-type',
+        timestamp: 1000,
+        attachment: { size: 100 } as AttachmentType,
+        pending: 0,
+        index: 0,
+        type: 'attachment',
+      });
+      insertLegacyJob(db, {
+        id: 'duplicate-1',
+        messageId: 'message-1',
+        timestamp: 1000,
+        attachment: {
+          size: 100,
+          contentType: 'image/jpeg',
+          digest: 'digest1',
+        } as AttachmentType,
+        pending: 0,
+        index: 0,
+        type: 'attachment',
+      });
+
+      const legacyJobs = db.prepare('SELECT * FROM attachment_downloads').all();
+      assert.strictEqual(legacyJobs.length, 6);
+
+      updateToVersion(db, 1040);
+
+      const newJobs = getAttachmentDownloadJobs(db);
+      assert.strictEqual(newJobs.length, 2);
+      assert.deepEqual(newJobs[1], {
+        messageId: 'message-1',
+        receivedAt: 1000,
+        sentAt: 1000,
+        attachment: {
+          size: 100,
+          contentType: 'image/png',
+          digest: 'digest1',
+          cdnKey: 'key1',
+        },
+        size: 100,
+        contentType: 'image/png',
+        digest: 'digest1',
+        active: 0,
+        attempts: 0,
+        attachmentType: 'attachment',
+        lastAttemptTimestamp: null,
+        retryAfter: null,
+      });
+      assert.deepEqual(newJobs[0], {
+        messageId: 'message-2',
+        receivedAt: 1001,
+        sentAt: 1001,
+        attachment: {
+          size: 100,
+          contentType: 'image/jpeg',
+          digest: 'digest2',
+          cdnKey: 'key2',
+        },
+        size: 100,
+        contentType: 'image/jpeg',
+        digest: 'digest2',
+        active: 0,
+        attempts: 1,
+        attachmentType: 'attachment',
+        lastAttemptTimestamp: null,
+        retryAfter: null,
+      });
+    });
+  });
+});
+
+function insertLegacyJob(
+  db: Database,
+  job: Partial<LegacyAttachmentDownloadJobType>
+): void {
+  db.prepare('INSERT OR REPLACE INTO messages (id) VALUES ($id)').run({
+    id: job.messageId,
+  });
+  const [query, params] = sql`
+    INSERT INTO attachment_downloads
+      (id, timestamp, pending, json)
+    VALUES
+      (
+        ${job.id},
+        ${job.timestamp},
+        ${job.pending},
+        ${objectToJSON(job)}
+      );
+  `;
+
+  db.prepare(query).run(params);
+}
diff --git a/ts/textsecure/downloadAttachment.ts b/ts/textsecure/downloadAttachment.ts
index 347907ebe470..daf3ad3cd89f 100644
--- a/ts/textsecure/downloadAttachment.ts
+++ b/ts/textsecure/downloadAttachment.ts
@@ -96,6 +96,8 @@ export async function downloadAttachmentV2(
   strictAssert(key, `${logId}: missing key`);
   strictAssert(isNumber(size), `${logId}: missing size`);
 
+  // TODO (DESKTOP-6845): download attachments differentially based on their
+  // media tier (i.e. transit tier or backup tier)
   const downloadStream = await server.getAttachmentV2(
     cdn,
     dropNull(cdnNumber),
diff --git a/ts/types/Attachment.ts b/ts/types/Attachment.ts
index 656ea5373971..be93fced7c72 100644
--- a/ts/types/Attachment.ts
+++ b/ts/types/Attachment.ts
@@ -70,7 +70,6 @@ export type AttachmentType = {
   flags?: number;
   thumbnail?: ThumbnailType;
   isCorrupted?: boolean;
-  downloadJobId?: string;
   cdnNumber?: number;
   cdnId?: string;
   cdnKey?: string;
@@ -696,7 +695,7 @@ export function hasNotResolved(attachment?: AttachmentType): boolean {
 
 export function isDownloading(attachment?: AttachmentType): boolean {
   const resolved = resolveNestedAttachment(attachment);
-  return Boolean(resolved && resolved.downloadJobId && resolved.pending);
+  return Boolean(resolved && resolved.pending);
 }
 
 export function hasFailed(attachment?: AttachmentType): boolean {
diff --git a/ts/types/AttachmentDownload.ts b/ts/types/AttachmentDownload.ts
new file mode 100644
index 000000000000..f3b6a41a9300
--- /dev/null
+++ b/ts/types/AttachmentDownload.ts
@@ -0,0 +1,56 @@
+// Copyright 2024 Signal Messenger, LLC
+// SPDX-License-Identifier: AGPL-3.0-only
+import { z } from 'zod';
+import { MIMETypeSchema, type MIMEType } from './MIME';
+import type { AttachmentType } from './Attachment';
+
+export const attachmentDownloadTypeSchema = z.enum([
+  'long-message',
+  'attachment',
+  'preview',
+  'contact',
+  'quote',
+  'sticker',
+]);
+
+export type AttachmentDownloadJobTypeType = z.infer<
+  typeof attachmentDownloadTypeSchema
+>;
+
+export type AttachmentDownloadJobType = {
+  messageId: string;
+  receivedAt: number;
+  sentAt: number;
+  attachmentType: AttachmentDownloadJobTypeType;
+  attachment: AttachmentType;
+  attempts: number;
+  active: boolean;
+  retryAfter: number | null;
+  lastAttemptTimestamp: number | null;
+  digest: string;
+  contentType: MIMEType;
+  size: number;
+};
+
+export const attachmentDownloadJobSchema = z.object({
+  messageId: z.string(),
+  receivedAt: z.number(),
+  sentAt: z.number(),
+  attachmentType: attachmentDownloadTypeSchema,
+  attachment: z
+    .object({ size: z.number(), contentType: MIMETypeSchema })
+    .passthrough(),
+  attempts: z.number(),
+  active: z.boolean(),
+  retryAfter: z.number().nullable(),
+  lastAttemptTimestamp: z.number().nullable(),
+  digest: z.string(),
+  contentType: MIMETypeSchema,
+  size: z.number(),
+  messageIdForLogging: z.string().optional(),
+}) satisfies z.ZodType<
+  Omit<AttachmentDownloadJobType, 'attachment' | 'contentType'> & {
+    contentType: string;
+    attachment: Record<string, unknown>;
+  }
+>;
diff --git a/ts/types/MIME.ts b/ts/types/MIME.ts
index 04f77b2a19fc..b6bb0109e766 100644
--- a/ts/types/MIME.ts
+++ b/ts/types/MIME.ts
@@ -1,7 +1,9 @@
 // Copyright 2018 Signal Messenger, LLC
 // SPDX-License-Identifier: AGPL-3.0-only
+import { z } from 'zod';
 
-export type MIMEType = string & { _mimeTypeBrand: never };
+export const MIMETypeSchema = z.string().brand('mimeType');
+export type MIMEType = z.infer<typeof MIMETypeSchema>;
 
 export const stringToMIMEType = (value: string): MIMEType => {
   return value as MIMEType;
diff --git a/ts/util/downloadAttachment.ts b/ts/util/downloadAttachment.ts
index 7ab95e8c2f4a..e47363ee3637 100644
--- a/ts/util/downloadAttachment.ts
+++ b/ts/util/downloadAttachment.ts
@@ -4,9 +4,10 @@
 import type { AttachmentType } from '../types/Attachment';
 import { downloadAttachmentV2 as doDownloadAttachment } from '../textsecure/downloadAttachment';
 
+export class AttachmentNotFoundOnCdnError extends Error {}
 export async function downloadAttachment(
   attachmentData: AttachmentType
-): Promise<AttachmentType | null> {
+): Promise<AttachmentType> {
   let migratedAttachment: AttachmentType;
 
   const { server } = window.textsecure;
@@ -30,7 +31,7 @@ export async function downloadAttachment(
   } catch (error) {
     // Attachments on the server expire after 30 days, then start returning 404 or 403
     if (error && (error.code === 404 || error.code === 403)) {
-      return null;
+      throw new AttachmentNotFoundOnCdnError(error.code);
     }
 
     throw error;
diff --git a/ts/util/exponentialBackoff.ts b/ts/util/exponentialBackoff.ts
index 87f29c3ac31d..618d628117c9 100644
--- a/ts/util/exponentialBackoff.ts
+++ b/ts/util/exponentialBackoff.ts
@@ -5,6 +5,7 @@ import * as durations from './durations';
 
 const BACKOFF_FACTOR = 1.9;
 const MAX_BACKOFF = 15 * durations.MINUTE;
+const FIRST_BACKOFF = 100 * BACKOFF_FACTOR;
 
 /**
  * For a given attempt, how long should we sleep (in milliseconds)?
@@ -16,12 +17,29 @@ const MAX_BACKOFF = 15 * durations.MINUTE;
  *
  * [0]: https://github.com/signalapp/Signal-iOS/blob/6069741602421744edfb59923d2fb3a66b1b23c1/SignalServiceKit/src/Util/OWSOperation.swift
  */
-export function exponentialBackoffSleepTime(attempt: number): number {
-  const failureCount = attempt - 1;
-  if (failureCount === 0) {
+
+export type ExponentialBackoffOptionsType = {
+  maxBackoffTime: number;
+  multiplier: number;
+  firstBackoffTime: number;
+};
+export function exponentialBackoffSleepTime(
+  attempt: number,
+  options: ExponentialBackoffOptionsType = {
+    maxBackoffTime: MAX_BACKOFF,
+    multiplier: BACKOFF_FACTOR,
+    firstBackoffTime: FIRST_BACKOFF,
+  }
+): number {
+  if (attempt === 1) {
     return 0;
   }
-  return Math.min(MAX_BACKOFF, 100 * BACKOFF_FACTOR ** failureCount);
+
+  return Math.min(
+    options.maxBackoffTime,
+    (options.firstBackoffTime / options.multiplier) *
+      options.multiplier ** (attempt - 1)
+  );
 }
 
 /**
@@ -31,7 +49,8 @@ export function exponentialBackoffSleepTime(attempt: number): number {
  * `desiredDurationMs` should be at least 1.
  */
 export function exponentialBackoffMaxAttempts(
-  desiredDurationMs: number
+  desiredDurationMs: number,
+  options?: ExponentialBackoffOptionsType
 ): number {
   let attempts = 0;
   let total = 0;
@@ -39,7 +58,7 @@ export function exponentialBackoffMaxAttempts(
   //   fast even for giant numbers, and is typically called just once at startup.
   do {
     attempts += 1;
-    total += exponentialBackoffSleepTime(attempts);
+    total += exponentialBackoffSleepTime(attempts, options);
   } while (total < desiredDurationMs);
   return attempts;
 }
diff --git a/ts/util/privacy.ts b/ts/util/privacy.ts
index e1089cae9aa8..446b1466dcac 100644
--- a/ts/util/privacy.ts
+++ b/ts/util/privacy.ts
@@ -167,6 +167,10 @@ export const redactCdnKey = (cdnKey: string): string => {
   return `${REDACTION_PLACEHOLDER}${cdnKey.slice(-3)}`;
 };
 
+export const redactGenericText = (text: string): string => {
+  return `${REDACTION_PLACEHOLDER}${text.slice(-3)}`;
+};
+
 const createRedactSensitivePaths = (
   paths: ReadonlyArray<string>
 ): RedactFunction => {
diff --git a/ts/util/queueAttachmentDownloads.ts b/ts/util/queueAttachmentDownloads.ts
index aa657ad8ddaa..86df8281ab52 100644
--- a/ts/util/queueAttachmentDownloads.ts
+++ b/ts/util/queueAttachmentDownloads.ts
@@ -2,7 +2,6 @@
 // SPDX-License-Identifier: AGPL-3.0-only
 
 import { partition } from 'lodash';
-import * as AttachmentDownloads from '../messageModifiers/AttachmentDownloads';
 import * as log from '../logging/log';
 import { isLongMessage } from '../types/MIME';
 import { getMessageIdForLogging } from './idForLogging';
@@ -29,6 +28,10 @@ import {
 import type { StickerType } from '../types/Stickers';
 import type { LinkPreviewType } from '../types/message/LinkPreviews';
 import { isNotNil } from './isNotNil';
+import {
+  AttachmentDownloadManager,
+  AttachmentDownloadUrgency,
+} from '../jobs/AttachmentDownloadManager';
 
 export type MessageAttachmentsDownloadedType = {
   bodyAttachment?: AttachmentType;
@@ -58,7 +61,8 @@ function getAttachmentSignatureSafe(
 // NOTE: If you're changing any logic in this function that deals with the
 // count then you'll also have to modify ./hasAttachmentsDownloads
 export async function queueAttachmentDownloads(
-  message: MessageAttributesType
+  message: MessageAttributesType,
+  urgency: AttachmentDownloadUrgency = AttachmentDownloadUrgency.STANDARD
 ): Promise<MessageAttachmentsDownloadedType | undefined> {
   const attachmentsToQueue = message.attachments || [];
   const messageId = message.id;
@@ -82,9 +86,11 @@ export async function queueAttachmentDownloads(
     log.error(`${idLog}: Received more than one long message attachment`);
   }
 
-  log.info(
-    `${idLog}: Queueing ${longMessageAttachments.length} long message attachment downloads`
-  );
+  if (longMessageAttachments.length > 0) {
+    log.info(
+      `${idLog}: Queueing ${longMessageAttachments.length} long message attachment downloads`
+    );
+  }
 
   if (longMessageAttachments.length > 0) {
     count += 1;
@@ -96,54 +102,77 @@ export async function queueAttachmentDownloads(
   }
 
   if (bodyAttachment) {
-    await AttachmentDownloads.addJob(bodyAttachment, {
+    await AttachmentDownloadManager.addJob({
+      attachment: bodyAttachment,
       messageId,
-      type: 'long-message',
-      index: 0,
+      attachmentType: 'long-message',
+      receivedAt: message.received_at,
+      sentAt: message.sent_at,
+      urgency,
     });
   }
 
-  log.info(
-    `${idLog}: Queueing ${normalAttachments.length} normal attachment downloads`
-  );
+  if (normalAttachments.length > 0) {
+    log.info(
+      `${idLog}: Queueing ${normalAttachments.length} normal attachment downloads`
+    );
+  }
   const { attachments, count: attachmentsCount } = await queueNormalAttachments(
-    idLog,
-    messageId,
-    normalAttachments,
-    message.editHistory?.flatMap(x => x.attachments ?? [])
+    {
+      idLog,
+      messageId,
+      attachments: normalAttachments,
+      otherAttachments: message.editHistory?.flatMap(x => x.attachments ?? []),
+      receivedAt: message.received_at,
+      sentAt: message.sent_at,
+      urgency,
+    }
   );
   count += attachmentsCount;
 
   const previewsToQueue = message.preview || [];
-  log.info(
-    `${idLog}: Queueing ${previewsToQueue.length} preview attachment downloads`
-  );
-  const { preview, count: previewCount } = await queuePreviews(
+  if (previewsToQueue.length > 0) {
+    log.info(
+      `${idLog}: Queueing ${previewsToQueue.length} preview attachment downloads`
+    );
+  }
+  const { preview, count: previewCount } = await queuePreviews({
     idLog,
     messageId,
-    previewsToQueue,
-    message.editHistory?.flatMap(x => x.preview ?? [])
-  );
+    previews: previewsToQueue,
+    otherPreviews: message.editHistory?.flatMap(x => x.preview ?? []),
+    receivedAt: message.received_at,
+    sentAt: message.sent_at,
+    urgency,
+  });
   count += previewCount;
 
-  log.info(
-    `${idLog}: Queueing ${message.quote?.attachments?.length ?? 0} ` +
-      'quote attachment downloads'
-  );
-  const { quote, count: thumbnailCount } = await queueQuoteAttachments(
+  const numQuoteAttachments = message.quote?.attachments?.length ?? 0;
+  if (numQuoteAttachments > 0) {
+    log.info(
+      `${idLog}: Queueing ${numQuoteAttachments} ` +
+        'quote attachment downloads'
+    );
+  }
+  const { quote, count: thumbnailCount } = await queueQuoteAttachments({
     idLog,
     messageId,
-    message.quote,
-    message.editHistory?.map(x => x.quote).filter(isNotNil) ?? []
-  );
+    quote: message.quote,
+    otherQuotes: message.editHistory?.map(x => x.quote).filter(isNotNil) ?? [],
+    receivedAt: message.received_at,
+    sentAt: message.sent_at,
+    urgency,
+  });
   count += thumbnailCount;
 
   const contactsToQueue = message.contact || [];
-  log.info(
-    `${idLog}: Queueing ${contactsToQueue.length} contact attachment downloads`
-  );
+  if (contactsToQueue.length > 0) {
+    log.info(
+      `${idLog}: Queueing ${contactsToQueue.length} contact attachment downloads`
+    );
+  }
   const contact = await Promise.all(
-    contactsToQueue.map(async (item, index) => {
+    contactsToQueue.map(async item => {
       if (!item.avatar || !item.avatar.avatar) {
         return item;
       }
@@ -158,10 +187,13 @@ export async function queueAttachmentDownloads(
         ...item,
         avatar: {
           ...item.avatar,
-          avatar: await AttachmentDownloads.addJob(item.avatar.avatar, {
+          avatar: await AttachmentDownloadManager.addJob({
+            attachment: item.avatar.avatar,
             messageId,
-            type: 'contact',
-            index,
+            attachmentType: 'contact',
+            receivedAt: message.received_at,
+            sentAt: message.sent_at,
+            urgency,
           }),
         },
       };
@@ -191,10 +223,13 @@ export async function queueAttachmentDownloads(
     }
     if (!data) {
       if (sticker.data) {
-        data = await AttachmentDownloads.addJob(sticker.data, {
+        data = await AttachmentDownloadManager.addJob({
+          attachment: sticker.data,
           messageId,
-          type: 'sticker',
-          index: 0,
+          attachmentType: 'sticker',
+          receivedAt: message.received_at,
+          sentAt: message.sent_at,
+          urgency,
         });
       } else {
         log.error(`${idLog}: Sticker data was missing`);
@@ -224,12 +259,15 @@ export async function queueAttachmentDownloads(
     editHistory = await Promise.all(
       editHistory.map(async edit => {
         const { attachments: editAttachments, count: editAttachmentsCount } =
-          await queueNormalAttachments(
+          await queueNormalAttachments({
             idLog,
             messageId,
-            edit.attachments,
-            attachments
-          );
+            attachments: edit.attachments,
+            otherAttachments: attachments,
+            receivedAt: message.received_at,
+            sentAt: message.sent_at,
+            urgency,
+          });
         count += editAttachmentsCount;
         if (editAttachmentsCount !== 0) {
           log.info(
@@ -239,7 +277,15 @@ export async function queueAttachmentDownloads(
         }
 
         const { preview: editPreview, count: editPreviewCount } =
-          await queuePreviews(idLog, messageId, edit.preview, preview);
+          await queuePreviews({
+            idLog,
+            messageId,
+            previews: edit.preview,
+            otherPreviews: preview,
+            receivedAt: message.received_at,
+            sentAt: message.sent_at,
+            urgency,
+          });
         count += editPreviewCount;
         if (editPreviewCount !== 0) {
           log.info(
@@ -274,12 +320,23 @@ export async function queueAttachmentDownloads(
   };
 }
 
-async function queueNormalAttachments(
-  idLog: string,
-  messageId: string,
-  attachments: MessageAttributesType['attachments'] = [],
-  otherAttachments: MessageAttributesType['attachments']
-): Promise<{
+async function queueNormalAttachments({
+  idLog,
+  messageId,
+  attachments = [],
+  otherAttachments,
+  receivedAt,
+  sentAt,
+  urgency,
+}: {
+  idLog: string;
+  messageId: string;
+  attachments: MessageAttributesType['attachments'];
+  otherAttachments: MessageAttributesType['attachments'];
+  receivedAt: number;
+  sentAt: number;
+  urgency: AttachmentDownloadUrgency;
+}): Promise<{
   attachments: Array<AttachmentType>;
   count: number;
 }> {
@@ -299,7 +356,7 @@ async function queueNormalAttachments(
 
   let count = 0;
   const nextAttachments = await Promise.all(
-    attachments.map((attachment, index) => {
+    attachments.map(attachment => {
       if (!attachment) {
         return attachment;
       }
@@ -329,10 +386,13 @@ async function queueNormalAttachments(
 
       count += 1;
 
-      return AttachmentDownloads.addJob(attachment, {
+      return AttachmentDownloadManager.addJob({
+        attachment,
         messageId,
-        type: 'attachment',
-        index,
+        attachmentType: 'attachment',
+        receivedAt,
+        sentAt,
+        urgency,
       });
     })
   );
@@ -358,12 +418,23 @@ function getLinkPreviewSignature(preview: LinkPreviewType): string | undefined {
   return `<${url}>${signature}`;
 }
 
-async function queuePreviews(
-  idLog: string,
-  messageId: string,
-  previews: MessageAttributesType['preview'] = [],
-  otherPreviews: MessageAttributesType['preview']
-): Promise<{ preview: Array<LinkPreviewType>; count: number }> {
+async function queuePreviews({
+  idLog,
+  messageId,
+  previews = [],
+  otherPreviews,
+  receivedAt,
+  sentAt,
+  urgency,
+}: {
+  idLog: string;
+  messageId: string;
+  previews: MessageAttributesType['preview'];
+  otherPreviews: MessageAttributesType['preview'];
+  receivedAt: number;
+  sentAt: number;
+  urgency: AttachmentDownloadUrgency;
+}): Promise<{ preview: Array<LinkPreviewType>; count: number }> {
   // Similar to queueNormalAttachments' logic for detecting same attachments
   // except here we also pick by link preview URL.
   const previewSignatures: Map<string, LinkPreviewType> = new Map();
@@ -378,7 +449,7 @@ async function queuePreviews(
   let count = 0;
 
   const preview = await Promise.all(
-    previews.map(async (item, index) => {
+    previews.map(async item => {
       if (!item.image) {
         return item;
       }
@@ -407,10 +478,13 @@ async function queuePreviews(
       count += 1;
       return {
         ...item,
-        image: await AttachmentDownloads.addJob(item.image, {
+        image: await AttachmentDownloadManager.addJob({
+          attachment: item.image,
           messageId,
-          type: 'preview',
-          index,
+          attachmentType: 'preview',
+          receivedAt,
+          sentAt,
+          urgency,
         }),
       };
     })
@@ -436,12 +510,23 @@ function getQuoteThumbnailSignature(
   return `<${quote.id}>${signature}`;
 }
 
-async function queueQuoteAttachments(
-  idLog: string,
-  messageId: string,
-  quote: QuotedMessageType | undefined,
-  otherQuotes: ReadonlyArray<QuotedMessageType>
-): Promise<{ quote?: QuotedMessageType; count: number }> {
+async function queueQuoteAttachments({
+  idLog,
+  messageId,
+  quote,
+  otherQuotes,
+  receivedAt,
+  sentAt,
+  urgency,
+}: {
+  idLog: string;
+  messageId: string;
+  quote: QuotedMessageType | undefined;
+  otherQuotes: ReadonlyArray<QuotedMessageType>;
+  receivedAt: number;
+  sentAt: number;
+  urgency: AttachmentDownloadUrgency;
+}): Promise<{ quote?: QuotedMessageType; count: number }> {
   let count = 0;
   if (!quote) {
     return { quote, count };
@@ -473,7 +558,7 @@ async function queueQuoteAttachments(
     quote: {
       ...quote,
       attachments: await Promise.all(
-        quote.attachments.map(async (item, index) => {
+        quote.attachments.map(async item => {
           if (!item.thumbnail) {
             return item;
           }
@@ -508,10 +593,13 @@ async function queueQuoteAttachments(
           count += 1;
           return {
             ...item,
-            thumbnail: await AttachmentDownloads.addJob(item.thumbnail, {
+            thumbnail: await AttachmentDownloadManager.addJob({
+              attachment: item.thumbnail,
               messageId,
-              type: 'quote',
-              index,
+              attachmentType: 'quote',
+              receivedAt,
+              sentAt,
+              urgency,
             }),
           };
         })