diff --git a/public/openapi/write.yaml b/public/openapi/write.yaml
index f62d1faca0..63c52430b8 100644
--- a/public/openapi/write.yaml
+++ b/public/openapi/write.yaml
@@ -118,6 +118,8 @@ paths:
     $ref: 'write/categories/cid/posts.yaml'
   /categories/{cid}/children:
     $ref: 'write/categories/cid/children.yaml'
+  /categories/{cid}/topics:
+    $ref: 'write/categories/cid/topics.yaml'
   /categories/{cid}/watch:
     $ref: 'write/categories/cid/watch.yaml'
   /categories/{cid}/privileges:
diff --git a/public/openapi/write/categories/cid/topics.yaml b/public/openapi/write/categories/cid/topics.yaml
new file mode 100644
index 0000000000..a14664b20c
--- /dev/null
+++ b/public/openapi/write/categories/cid/topics.yaml
@@ -0,0 +1,75 @@
+get:
+  tags:
+    - categories
+  summary: get topics
+  description: |
+    This operation returns a set of topics in the requested category.
+
+    The number of topics returned is defined by the "Topics per Page" (`topicsPerPage`) setting under ACP > Settings > Pagination.
+  parameters:
+    - in: path
+      name: cid
+      schema:
+        type: string
+      required: true
+      description: a valid category id, `0` for global privileges, `admin` for admin privileges
+      example: 1
+    - in: query
+      name: 'query'
+      schema:
+        type: string
+      required: false
+      description: Likely unused — a URI-encoded JSON string containing values that are passed to `getCategoryTopics`.
+      example: ''
+    - in: query
+      name: 'after'
+      schema:
+        type: string
+      required: false
+      description: The index to start at when querying for the next set of topics. This parameter would be more aptly named `start`.
+      example: '0'
+    - in: query
+      name: 'sort'
+      schema:
+        type: string
+      required: false
+      description: Likely deprecated — the sorting method of topics (use `categoryTopicSort` instead.)
+      example: ''
+    - in: query
+      name: 'categoryTopicSort'
+      schema:
+        type: string
+      required: false
+      description: The sorting method of topics
+      example: 'newest_to_oldest'
+    - in: query
+      name: 'direction'
+      schema:
+        type: string
+      required: false
+      description: The sorting of returned results (if you scroll up you want the topics reversed). Set to "-1" for reversed results.
+      example: '1'
+  responses:
+    '200':
+      description: categories topics successfully retrieved
+      content:
+        application/json:
+          schema:
+            type: object
+            properties:
+              status:
+                $ref: ../../../components/schemas/Status.yaml#/Status
+              response:
+                type: object
+                properties:
+                  topics:
+                    type: array
+                    items:
+                      $ref: ../../../components/schemas/TopicObject.yaml#/TopicObject
+                  nextStart:
+                    type: number
+                  privileges:
+                    type: object
+                    additionalProperties:
+                      type: boolean
+                      description: A set of privileges with either true or false
\ No newline at end of file
diff --git a/public/src/client/category.js b/public/src/client/category.js
index b14a80d0c9..e1ab97431f 100644
--- a/public/src/client/category.js
+++ b/public/src/client/category.js
@@ -123,7 +123,7 @@ define('forum/category', [
 
 		hooks.fire('action:topics.loading');
 		const params = utils.params();
-		infinitescroll.loadMore('categories.loadMore', {
+		infinitescroll.loadMore(`/categories/${ajaxify.data.cid}/topics`, {
 			cid: ajaxify.data.cid,
 			after: after,
 			direction: direction,
diff --git a/public/src/client/infinitescroll.js b/public/src/client/infinitescroll.js
index bd6f98d178..838f164f32 100644
--- a/public/src/client/infinitescroll.js
+++ b/public/src/client/infinitescroll.js
@@ -1,7 +1,7 @@
 'use strict';
 
 
-define('forum/infinitescroll', ['hooks', 'alerts'], function (hooks, alerts) {
+define('forum/infinitescroll', ['hooks', 'alerts', 'api'], function (hooks, alerts, api) {
 	const scroll = {};
 	let callback;
 	let previousScrollTop = 0;
@@ -72,7 +72,9 @@ define('forum/infinitescroll', ['hooks', 'alerts'], function (hooks, alerts) {
 		const hookData = { method: method, data: data };
 		hooks.fire('action:infinitescroll.loadmore', hookData);
 
-		socket.emit(hookData.method, hookData.data, function (err, data) {
+		const call = hookData.method.startsWith('/') ? api.get : socket.emit;
+
+		call(hookData.method, hookData.data, function (err, data) {
 			if (err) {
 				loadingMore = false;
 				return alerts.error(err);
diff --git a/src/api/categories.js b/src/api/categories.js
index 7cb7a17f69..774091fd61 100644
--- a/src/api/categories.js
+++ b/src/api/categories.js
@@ -1,5 +1,6 @@
 'use strict';
 
+const meta = require('../meta');
 const categories = require('../categories');
 const topics = require('../topics');
 const events = require('../events');
@@ -106,6 +107,47 @@ categoriesAPI.getChildren = async (caller, { cid, start }) => {
 	return { categories: payload };
 };
 
+categoriesAPI.getTopics = async (caller, data) => {
+	data.query = data.query || {};
+	const [userPrivileges, settings, targetUid] = await Promise.all([
+		privileges.categories.get(data.cid, caller.uid),
+		user.getSettings(caller.uid),
+		user.getUidByUserslug(data.query.author),
+	]);
+
+	if (!userPrivileges.read) {
+		throw new Error('[[error:no-privileges]]');
+	}
+
+	const infScrollTopicsPerPage = 20;
+	const sort = data.sort || data.categoryTopicSort || meta.config.categoryTopicSort || 'newest_to_oldest';
+
+	let start = Math.max(0, parseInt(data.after || 0, 10));
+
+	if (data.direction === -1) {
+		start -= infScrollTopicsPerPage;
+	}
+
+	let stop = start + infScrollTopicsPerPage - 1;
+
+	start = Math.max(0, start);
+	stop = Math.max(0, stop);
+	const result = await categories.getCategoryTopics({
+		uid: caller.uid,
+		cid: data.cid,
+		start,
+		stop,
+		sort,
+		settings,
+		query: data.query,
+		tag: data.query.tag,
+		targetUid,
+	});
+	categories.modifyTopicsByPrivilege(result.topics, userPrivileges);
+
+	return { ...result, privileges: userPrivileges };
+};
+
 categoriesAPI.setWatchState = async (caller, { cid, state, uid }) => {
 	let targetUid = caller.uid;
 	const cids = Array.isArray(cid) ? cid.map(cid => parseInt(cid, 10)) : [parseInt(cid, 10)];
diff --git a/src/controllers/write/categories.js b/src/controllers/write/categories.js
index 133ec2c055..80ee961fbf 100644
--- a/src/controllers/write/categories.js
+++ b/src/controllers/write/categories.js
@@ -51,6 +51,13 @@ Categories.getChildren = async (req, res) => {
 	helpers.formatApiResponse(200, res, await api.categories.getChildren(req, { cid, start }));
 };
 
+Categories.getTopics = async (req, res) => {
+	const { cid } = req.params;
+	const result = await api.categories.getTopics(req, { ...req.query, cid });
+
+	helpers.formatApiResponse(200, res, result);
+};
+
 Categories.setWatchState = async (req, res) => {
 	const { cid } = req.params;
 	let { uid, state } = req.body;
diff --git a/src/routes/write/categories.js b/src/routes/write/categories.js
index 9121ee9a7f..ca149a54da 100644
--- a/src/routes/write/categories.js
+++ b/src/routes/write/categories.js
@@ -19,6 +19,7 @@ module.exports = function () {
 	setupApiRoute(router, 'get', '/:cid/count', [...middlewares, middleware.assert.category], controllers.write.categories.getTopicCount);
 	setupApiRoute(router, 'get', '/:cid/posts', [...middlewares, middleware.assert.category], controllers.write.categories.getPosts);
 	setupApiRoute(router, 'get', '/:cid/children', [...middlewares, middleware.assert.category], controllers.write.categories.getChildren);
+	setupApiRoute(router, 'get', '/:cid/topics', [...middlewares, middleware.assert.category], controllers.write.categories.getTopics);
 
 	setupApiRoute(router, 'put', '/:cid/watch', [...middlewares, middleware.assert.category], controllers.write.categories.setWatchState);
 	setupApiRoute(router, 'delete', '/:cid/watch', [...middlewares, middleware.assert.category], controllers.write.categories.setWatchState);
diff --git a/src/socket.io/categories.js b/src/socket.io/categories.js
index a62d55edfe..934defaeac 100644
--- a/src/socket.io/categories.js
+++ b/src/socket.io/categories.js
@@ -1,7 +1,6 @@
 'use strict';
 
 const categories = require('../categories');
-const privileges = require('../privileges');
 const user = require('../user');
 const topics = require('../topics');
 const api = require('../api');
@@ -38,47 +37,15 @@ SocketCategories.loadMore = async function (socket, data) {
 		throw new Error('[[error:invalid-data]]');
 	}
 	data.query = data.query || {};
-	const [userPrivileges, settings, targetUid] = await Promise.all([
-		privileges.categories.get(data.cid, socket.uid),
-		user.getSettings(socket.uid),
-		user.getUidByUserslug(data.query.author),
-	]);
 
-	if (!userPrivileges.read) {
-		throw new Error('[[error:no-privileges]]');
-	}
+	const result = await api.categories.getTopics(socket, data);
 
-	const infScrollTopicsPerPage = 20;
-	const sort = data.sort || data.categoryTopicSort;
-
-	let start = Math.max(0, parseInt(data.after, 10));
-
-	if (data.direction === -1) {
-		start -= infScrollTopicsPerPage;
-	}
-
-	let stop = start + infScrollTopicsPerPage - 1;
-
-	start = Math.max(0, start);
-	stop = Math.max(0, stop);
-	const result = await categories.getCategoryTopics({
-		uid: socket.uid,
-		cid: data.cid,
-		start: start,
-		stop: stop,
-		sort: sort,
-		settings: settings,
-		query: data.query,
-		tag: data.query.tag,
-		targetUid: targetUid,
-	});
-	categories.modifyTopicsByPrivilege(result.topics, userPrivileges);
-
-	result.privileges = userPrivileges;
+	// Backwards compatibility — unsure of current usage.
 	result.template = {
 		category: true,
 		name: 'category',
 	};
+
 	return result;
 };