Introduction to Atlassian Connect

To an end-user, your add-on should appear as a fully integrated part of the Atlassian application. Once your add-on is registered with the application, features are delivered from the UI and workflows of the host application. This deep level of integration is part of what makes Atlassian Connect add-ons so powerful. (This content and diagram have been taken from the Atlassian Connect Documentation Guide: –

Here, I am going to introduce you to the Atlassian Connect add-ons development.

How to create your first add-on for Jira On Demand?

For developing your first add-on you need to install the Node.js, SDK and ACE (Atlassian Connect Express) toolkit.
For developing your first add-on you need to create your developing environment which is also called your local environment, where you will perform your add-on development.

There could be three environments for your Add-on:-

1- Local Environment
2- Test Environment
3- Production Environment

Configuring Development Environment

Local (Development) Environment Setup

1- For Jira On Demand we first need SDK in our machine. After setting up the SDK check atlas-version for your
confirmation by typing Atlassian-version command on CMD.
2- Now download and install Node.js by clicking on the link https://nodejs.org/en/
3- Open CMD & Install ACE by using this command npm install -g atlas-connect
4- Create your ACE project by using the given command
Atlas-connect new project name
5. Change directory by typing cd project name
6- Install all dependencies for your project by typing npm install command on cmd in your project directory.
Note: – You can add or install node modules by using npm install node module name command.
7- Change your port to 8000 for your npm server in config.json.
8- As well as you can do all configuration in your config.json. For example: – you can change your port, and other
required URL according to your requirement.
9- Start your Jira On Demand instance by using the given command
atlas-run-standalone –product Jira –version 7.0.0-OD-04-018 –bundled-plugins com.atlassian.bundles:json-schema-validator-atlassian-bundle:1.0.4,com.atlassian.webhooks:atlassian-webhooks-plugin:2.0.0,com.atlassian.jwt:jwt-plugin:1.2.2,com.atlassian.upm:atlassian-universal-plugin-manager-plugin:2.19.4-D20150819T002936,com.atlassian.plugins:atlassian-connect-plugin:1.1.48 –jvmargs -Datlassian.upm.on.demand=true
After which you can access your Jira in cloud mode by going to this URL:-

Now you can login in to Jira Cloud by using these credentials.
Username:admin
Password:admin
10- Start your local server by using the command node app.js
11- You can confirm your files by visiting this kind of a URL 
12- For uploading(manually) the add-on on your local environment use the following process:
Go to Add-ons (right-hand side of your Jira and click on * icon) and select Manage add-ons.
Now click on upload add-on and type the given URL for uploading your add-on on your local environment if you
want to upload it(add-on) manually, otherwise, it will automatically upload in your local environment.
Example of Add-on URL for Uploading in your local environment