diff --git a/app/models/request-group.js b/app/models/request-group.js
index 0e4887062..dba1b8f76 100644
--- a/app/models/request-group.js
+++ b/app/models/request-group.js
@@ -1,10 +1,21 @@
+// @flow
 import * as db from '../common/database';
+import type {BaseModel} from './index';
 
 export const name = 'Folder';
 export const type = 'RequestGroup';
 export const prefix = 'fld';
 export const canDuplicate = true;
 
+type BaseRequestGroup = {
+  name: string,
+  description: string,
+  environment: Object,
+  metaSortKey: number
+};
+
+export type RequestGroup = BaseModel & BaseRequestGroup;
+
 export function init () {
   return {
     name: 'New Folder',
@@ -14,39 +25,39 @@ export function init () {
   };
 }
 
-export function migrate (doc) {
+export function migrate (doc: RequestGroup) {
   return doc;
 }
 
-export function create (patch = {}) {
+export function create (patch: Object = {}): Promise<RequestGroup> {
   if (!patch.parentId) {
-    throw new Error('New Requests missing `parentId`', patch);
+    throw new Error('New RequestGroup missing `parentId`: ' + JSON.stringify(patch));
   }
 
   return db.docCreate(type, patch);
 }
 
-export function update (requestGroup, patch) {
+export function update (requestGroup: RequestGroup, patch: Object = {}): Promise<RequestGroup> {
   return db.docUpdate(requestGroup, patch);
 }
 
-export function getById (id) {
+export function getById (id: string): Promise<RequestGroup | null> {
   return db.get(type, id);
 }
 
-export function findByParentId (parentId) {
+export function findByParentId (parentId: string): Promise<Array<RequestGroup>> {
   return db.find(type, {parentId});
 }
 
-export function remove (requestGroup) {
+export function remove (requestGroup: RequestGroup): Promise<void> {
   return db.remove(requestGroup);
 }
 
-export function all () {
+export function all (): Promise<Array<RequestGroup>> {
   return db.all(type);
 }
 
-export async function duplicate (requestGroup) {
+export async function duplicate (requestGroup: RequestGroup): Promise<RequestGroup> {
   const name = `${requestGroup.name} (Copy)`;
 
   // Get sort key of next request
diff --git a/app/ui/components/sidebar/sidebar-children.js b/app/ui/components/sidebar/sidebar-children.js
index d6aa307fc..7d68994c3 100644
--- a/app/ui/components/sidebar/sidebar-children.js
+++ b/app/ui/components/sidebar/sidebar-children.js
@@ -1,11 +1,40 @@
-import React, {PureComponent} from 'react';
-import PropTypes from 'prop-types';
+// @flow
+import React from 'react';
 import SidebarRequestRow from './sidebar-request-row';
 import SidebarRequestGroupRow from './sidebar-request-group-row';
 import * as models from '../../../models/index';
+import type {RequestGroup} from '../../../models/request-group';
+import type {Workspace} from '../../../models/workspace';
+import type {Request} from '../../../models/request';
 
-class SidebarChildren extends PureComponent {
-  _renderChildren (children) {
+type Child = {
+  doc: Request | RequestGroup,
+  children: Array<Child>,
+  collapsed: boolean
+};
+
+type Props = {
+  // Required
+  handleActivateRequest: Function,
+  handleCreateRequest: Function,
+  handleCreateRequestGroup: Function,
+  handleSetRequestGroupCollapsed: Function,
+  handleDuplicateRequest: Function,
+  handleDuplicateRequestGroup: Function,
+  handleGenerateCode: Function,
+  handleCopyAsCurl: Function,
+  moveDoc: Function,
+  childObjects: Array<Child>,
+  workspace: Workspace,
+
+  // Optional
+  activeRequest?: Request
+};
+
+class SidebarChildren extends React.PureComponent {
+  props: Props;
+
+  _renderChildren (children: Array<Child>) {
     const {
       handleCreateRequest,
       handleCreateRequestGroup,
@@ -95,22 +124,4 @@ class SidebarChildren extends PureComponent {
   }
 }
 
-SidebarChildren.propTypes = {
-  // Required
-  handleActivateRequest: PropTypes.func.isRequired,
-  handleCreateRequest: PropTypes.func.isRequired,
-  handleCreateRequestGroup: PropTypes.func.isRequired,
-  handleSetRequestGroupCollapsed: PropTypes.func.isRequired,
-  handleDuplicateRequest: PropTypes.func.isRequired,
-  handleDuplicateRequestGroup: PropTypes.func.isRequired,
-  handleGenerateCode: PropTypes.func.isRequired,
-  handleCopyAsCurl: PropTypes.func.isRequired,
-  moveDoc: PropTypes.func.isRequired,
-  childObjects: PropTypes.arrayOf(PropTypes.object).isRequired,
-  workspace: PropTypes.object.isRequired,
-
-  // Optional
-  activeRequest: PropTypes.object
-};
-
 export default SidebarChildren;