What does the developer platform update do?

Develop, Build & Integrate CMS Development
1

I am planning to move to the new developer platform. It asks me to update the current account to unlock the features. There is also a popup shows thisupdate can’t be undo. What I am concerning is that the impact on the existing apps in this account. If I click upgrade, what would happen next? Can I continue use existing features like workflow, extensions and integration? Will the UI be changed dramatically?

Below is the information shown when I try to update to the new developer platform:

Projects are now part of the new developer platform

Update this account to unlock our reinvented development tools

2

Hey there, @JZhao -
Tagging in a few of our CMS API experts here to lend a hand as well: @Bortami, @eburnaman, and @nickdeckerdevs1 - do you all have any additional insights or experiences to share regarding the migration to the new developer platform?

The good news is that updating your account to the new platform does not automatically break or change your legacy apps.

Your current apps will be moved to a section called Legacy Apps in the left-hand navigation.

They will continue to function exactly as they do now. Your existing access tokens, webhooks, and extensions remain available.

You are not required to rewrite your code immediately. You can continue to maintain these “Legacy” apps, though new features are designed for the new Projects framework.

The interface of your developer account will change to the new Developer Overview.

Instead of the old dashboard, you will see a new sidebar with sections for Overview, Projects, and Legacy Apps.

Projects is the new file-based framework (often used with the HubSpot CLI), while your existing work will live under Legacy Apps.

As the popup warns, once you convert your developer account to the new platform experience, you cannot revert to the old UI. However, since your existing apps are preserved as “Legacy Apps,” this is primarily a change in how you access them rather than a change to the apps themselves.

HubSpot Developer Documentation: Developer Platform Overview

Migration Guide: Migrating existing apps to Projects

Let us know if you have any other questions as you explore the new view! Hope this helps.

3

Thanks for explainning. Can I confirm that the impact only on developer account? Is there any impact on the real customer dashboard after making this update?

4

Hi @JZhao , good follow-up question, and it’s an important distinction to clarify.

Yes, the impact is only on the developer account itself, not on any connected customer portals. When you upgrade to the new developer platform, you’re changing how you manage apps, projects, and tooling inside the developer account. Nothing changes in end-user HubSpot portals, CRM UI, workflows, or customer-facing dashboards.

To be very explicit: existing customer accounts that have your apps installed will not see any UI changes, feature removals, or behavior differences as a result of this upgrade. Tokens, extensions, webhooks, workflows, and integrations keep working exactly as they do today.

What changes is mainly organizational and tooling-related on the developer side. Your legacy apps get grouped under “Legacy Apps,” and the new Projects framework becomes available for building and managing newer apps going forward. This is about how code, configs, and assets are structured and deployed, not about runtime behavior in customer portals.

The “can’t be undone” warning is really about the developer UI and account structure. HubSpot doesn’t offer a way to revert to the old developer dashboard once you opt into the new one, but there’s no irreversible impact on production usage or customer data.

In short: safe to upgrade from a customer-impact perspective. You can continue running existing apps as-is, and adopt Projects only when you’re ready. Hope that puts your mind at ease.