I have built a REST api that connects the hubspot api and some additional functionality with the hubspot data.
I need to display these additional functionalities into an hubspot frontend app(or package) , unfortunately i havent seen any frontend framework that helps me directly interact with the REST api and also be able to install the App(frontend) package into the Hubspot account.
Lets say for example my rest api interacts with contacts using the hubspot api , i add an extra field called description using my rest api to the contacts object.
i need to display the description field in hubspot as a package that i own/develop/deploy , integrating with the hubspot account such that other ppl can also install the package i own.
I need :
1) A frontend framework that helps me develop My App
2) Docs Related to the framework
3) any github repo’s that has an example of such app if possible
Thank you very much
Hey, @DigvijayNarayan 
Thanks for your question. If you are looking for something similar to a full custom page framework, that is not currently possible. Your best bet in working with HubSpot will be UI Extensions via Custom Cards. Note, this type of customization is for object record pages and is not something that creates a standalone page within HubSpot.
Resources:
- Create UI extensions with React (BETA)
- Create a project (BETA)
- UI extensions SDK reference
- Quickstart guide
- Other sample projects
Best,
Jaycee
Hey @DigvijayNarayan ,
As @Jaycee_Lewis explained, if you are looking for something similar to a full custom page framework, that is not currently possible.
You’re describing a scenario that perfectly aligns with building a HubSpot Custom CRM Card + Custom UI Extension using the HubSpot CRM Development Tools.
This allows you to:
- Build a frontend app (React/Next.js supported)
- Interact with your custom REST API
Example GitHub Repos :
Here is a custom CRM card that was developed by my team to easily download Deal line‑items from HubSpot as a CSV file, right from the record sidebar.
References to follow: Hubspot CRM Cards Documentation
Regards,
Kosala.
That’s awesome, @kosalaindrasiri 
Thank you very much for sharing! — Jaycee
Thank you for your response , HubSpot CRM Development Tools are a part of a paid plan or do they come with the free developer account?
@DigvijayNarayan Features like custom CRM cards and UI extensions are part of a beta program that requires a Sales Hub Enterprise or Service Hub Enterprise subscription.
HubSpot also offers developer test accounts, which are free and provide access to a 90-day trial of many enterprise features. These accounts are ideal for testing and development purposes, but come with certain limitations.
- Kosala