diff --git a/keyserver/src/endpoints.js b/keyserver/src/endpoints.js
--- a/keyserver/src/endpoints.js
+++ b/keyserver/src/endpoints.js
@@ -42,6 +42,7 @@
   threadUpdateResponder,
   threadCreationResponder,
   threadJoinResponder,
+  threadFetchMediaResponder,
 } from './responders/thread-responders';
 import {
   userSubscriptionUpdateResponder,
@@ -133,6 +134,10 @@
     responder: messageFetchResponder,
     requiredPolicies: baseLegalPolicies,
   },
+  fetch_thread_media: {
+    responder: threadFetchMediaResponder,
+    requiredPolicies: baseLegalPolicies,
+  },
   get_session_public_keys: {
     responder: getSessionPublicKeysResponder,
     requiredPolicies: baseLegalPolicies,
diff --git a/keyserver/src/fetchers/upload-fetchers.js b/keyserver/src/fetchers/upload-fetchers.js
--- a/keyserver/src/fetchers/upload-fetchers.js
+++ b/keyserver/src/fetchers/upload-fetchers.js
@@ -5,6 +5,7 @@
 import type { Media } from 'lib/types/media-types';
 import type { MediaMessageServerDBContent } from 'lib/types/messages/media.js';
 import { getUploadIDsFromMediaMessageServerDBContents } from 'lib/types/messages/media.js';
+import type { ThreadFetchMediaResult } from 'lib/types/thread-types';
 import { ServerError } from 'lib/utils/errors';
 
 import { dbQuery, SQL } from '../database/database';
@@ -119,7 +120,7 @@
 async function fetchMediaForThread(
   threadID: string,
   limit?: number,
-): Promise<$ReadOnlyArray<Media>> {
+): Promise<ThreadFetchMediaResult> {
   const limitQuery = limit ? SQL`LIMIT ${limit}` : SQL``;
   const query = SQL`
     SELECT id AS uploadID, secret AS uploadSecret,
@@ -129,7 +130,9 @@
     ORDER BY creation_time DESC
   `.append(limitQuery);
   const [uploads] = await dbQuery(query);
-  return uploads.map(mediaFromRow);
+  return {
+    media: uploads.map(mediaFromRow),
+  };
 }
 
 async function fetchUploadsForMessage(
diff --git a/keyserver/src/responders/thread-responders.js b/keyserver/src/responders/thread-responders.js
--- a/keyserver/src/responders/thread-responders.js
+++ b/keyserver/src/responders/thread-responders.js
@@ -15,6 +15,8 @@
   type NewThreadResponse,
   type ServerThreadJoinRequest,
   type ThreadJoinResult,
+  type ThreadFetchMediaResult,
+  type ThreadFetchMediaRequest,
   threadTypes,
 } from 'lib/types/thread-types';
 import { values } from 'lib/utils/objects';
@@ -27,6 +29,7 @@
 
 import { createThread } from '../creators/thread-creator';
 import { deleteThread } from '../deleters/thread-deleters';
+import { fetchMediaForThread } from '../fetchers/upload-fetchers';
 import type { Viewer } from '../session/viewer';
 import {
   updateRole,
@@ -176,6 +179,19 @@
   return await joinThread(viewer, request);
 }
 
+const threadFetchMediaRequestInputValidator = tShape({
+  threadID: t.String,
+  limit: t.maybe(t.Number),
+});
+async function threadFetchMediaResponder(
+  viewer: Viewer,
+  input: any,
+): Promise<ThreadFetchMediaResult> {
+  const request: ThreadFetchMediaRequest = input;
+  await validateInput(viewer, threadFetchMediaRequestInputValidator, request);
+  return await fetchMediaForThread(request.threadID, request.limit);
+}
+
 export {
   threadDeletionResponder,
   roleUpdateResponder,
@@ -184,5 +200,6 @@
   threadUpdateResponder,
   threadCreationResponder,
   threadJoinResponder,
+  threadFetchMediaResponder,
   newThreadRequestInputValidator,
 };
diff --git a/lib/actions/thread-actions.js b/lib/actions/thread-actions.js
--- a/lib/actions/thread-actions.js
+++ b/lib/actions/thread-actions.js
@@ -2,6 +2,7 @@
 
 import invariant from 'invariant';
 
+import type { Media } from '../types/media-types';
 import type {
   ChangeThreadSettingsPayload,
   LeaveThreadPayload,
@@ -10,6 +11,7 @@
   NewThreadResult,
   ClientThreadJoinRequest,
   ThreadJoinPayload,
+  ThreadFetchMediaRequest,
 } from '../types/thread-types';
 import type { CallServerEndpoint } from '../utils/call-server-endpoint';
 import { values } from '../utils/objects';
@@ -162,6 +164,15 @@
   };
 };
 
+const fetchThreadMedia = (
+  callServerEndpoint: CallServerEndpoint,
+): ((
+  request: ThreadFetchMediaRequest,
+) => Promise<$ReadOnlyArray<Media>>) => async request => {
+  const response = await callServerEndpoint('fetch_thread_media', request);
+  return response.media;
+};
+
 export {
   deleteThreadActionTypes,
   deleteThread,
@@ -177,4 +188,5 @@
   joinThread,
   leaveThreadActionTypes,
   leaveThread,
+  fetchThreadMedia,
 };
diff --git a/lib/types/endpoints.js b/lib/types/endpoints.js
--- a/lib/types/endpoints.js
+++ b/lib/types/endpoints.js
@@ -61,6 +61,7 @@
   FETCH_ENTRY_REVISIONS: 'fetch_entry_revisions',
   FETCH_ERROR_REPORT_INFOS: 'fetch_error_report_infos',
   FETCH_MESSAGES: 'fetch_messages',
+  FETCH_THREAD_MEDIA: 'fetch_thread_media',
   GET_SESSION_PUBLIC_KEYS: 'get_session_public_keys',
   JOIN_THREAD: 'join_thread',
   LEAVE_THREAD: 'leave_thread',
diff --git a/lib/types/thread-types.js b/lib/types/thread-types.js
--- a/lib/types/thread-types.js
+++ b/lib/types/thread-types.js
@@ -4,6 +4,7 @@
 
 import type { Shape } from './core';
 import type { CalendarQuery, RawEntryInfo } from './entry-types';
+import type { Media } from './media-types';
 import type {
   RawMessageInfo,
   MessageTruncationStatuses,
@@ -434,6 +435,14 @@
   +userInfos: $ReadOnlyArray<UserInfo>,
 };
 
+export type ThreadFetchMediaResult = {
+  +media: $ReadOnlyArray<Media>,
+};
+export type ThreadFetchMediaRequest = {
+  +threadID: string,
+  +limit?: number,
+};
+
 export type SidebarInfo = {
   +threadInfo: ThreadInfo,
   +lastUpdatedTime: number,