Modal Support for Apps/Extensions

When working with extensions, mainly custom fields, there are a few situations where we might need to open some pop-ups or modals. You can use "window.open" to launch a new browser window to address these use cases. Although the use case is handled by this method, the modal that is opened is not all-inclusive. You can use the "venus-components" to open a modal within apps and extensions to display additional information, collect additional inputs from users, or draw attention to a specific feature (or features) on a page, etc.

Integrating Venus Components With App/Extension

Following are the prerequisites and steps to create and add a modal for apps/extension.


The Contentstack Venus Component Library best works with React version >= 16.8.0

Required Packages:

  • @contentstack/app-sdk (1.1.1 or higher)
  • @contentstack/venus-components (1.0.4 or higher)


  1. Import CSS from `@contentstack/venus-components`
  2. import "@contentstack/venus-components/build/main.css";
  3. Link a DOM Element for the snapshot:
    The snapshot of referenced DOM Element will be rendered in-place of the custom field when the modal is opened.
  4. window.iframeRef = document.getElementById('root');
  5. Link post-robot connection to handle events:
  6. window.postRobot = sdk.postRobot

When everything is set up, the 'cbModal' component from '@contentstack/venus-components' may be used to open the modal.

Code Snippet for the Modal

App Component

import { useEffect, useRef } from "react";
import ContentstackAppSDK from "@contentstack/app-sdk";
import { Button, cbModal } from "@contentstack/venus-components";
import "@contentstack/venus-components/build/main.css";
import SelectModal from "./components/SelectAsset";

import "./styles.css"; 

function App() {
 const ref = useRef(null);
 useEffect(() => {
   ContentstackAppSDK.init().then((sdk) => {
     // The snapshot of referenced DOM Element will render in-place of custom field when modal is opened
     const iframeWrapperRef = ref.current
     // or
     // const iframeWrapperRef = document.getElementById('root')
     window.iframeRef = iframeWrapperRef;
     window.postRobot = sdk.postRobot
 }, []);
 const handleClick = (e) => {
     component: (props) => (<SelectModal {...props} />),
     modalProps: {
       size: "max"
 return (
   <div ref={ref} className="extension-wrapper">
     <div className="btn-wrapper">
       <Button buttonType="tertiary-outline" onClick={handleClick}>
         Choose a file
       <span className="text">
       <span onClick={() => {}}
         Upload a new File
export default App;

Modal Component

import React from "react"
import { ModalFooter, ModalBody, ModalHeader, ButtonGroup, Button } from "@contentstack/venus-components"
const SelectModal = (props) => {
   return (
           <ModalHeader title={"Select Asset"} closeModal={props.closeModal} />
           <ModalBody className="modalBodyCustomClass">
               <div className="dummy-body">
                   Contenstack Asset Picker
                   <Button onClick={props.closeModal} buttonType="light">
                   <Button onClick={props.closeModal} icon="SaveWhite" disabled>
                       Add Selected Asset
export default SelectModal;


.text {
 font-family: Inter;
 padding: 0 0.65rem;
 font-size: 14px;

.upload-btn {
 font-family: Inter;
 cursor: pointer;
 font-size: 14px;

.upload-btn:hover {
 color: #6c5ce7;

.btn-wrapper {
 margin: 10px 0 2px 10px;

.dummy-body {
 height: 330px;
 width: 100%;
 display: flex;
 align-items: center;
 justify-content: center;
 font-family: Inter;



Additional Resource: For a comprehensive collection of Contentstack’s UI components which can be used to build UI Extensions and Contentstack-based applications, please refer to the Contentstack Venus Component Library and the App SDK documentation.

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