Legacy Public App Creation Sunset

Written by Hannah Seligson | Apr 23, 2026 1:12:02 PM

Beginning May 26, 2026, the ability to create new legacy public apps via the Developer Platform UI will be permanently disabled. New public app development should use the Projects-based app platform.

What's changing?

The Developer Platform UI will no longer allow the creation of new legacy public apps. The rollout occurs on two timelines based on account creation date:

New accounts (created on or after May 26, 2026): Legacy public app creation is disabled as of May 26, 2026.
Existing accounts (created before May 26, 2026): Legacy public app creation is disabled as of June 23, 2026.

Existing legacy public apps are not affected by this change. They will continue to function as-is. Existing or new legacy private apps are also not affected at this time. A separate migration initiative, with its own timeline and tooling, will address the migration of existing legacy public apps to the Projects-based platform.

How it works

To create apps intended for listing in the Marketplace, use the HubSpot CLI with Projects-based tooling. Project-based apps support CLI-based workflows, UI extensions, app cards, and dedicated deployment tooling. Follow the developer documentation to set up your environment and create your first project-based app.

Key dates and next steps:

May 26, 2026: Legacy public app creation is disabled for all accounts created on or after this date.
June 23, 2026: Legacy public app creation is disabled for all accounts created before May 26, 2026.

To get ready:

If you are building a new app intended for the Marketplace, begin using the Projects-based platform now.
Review the HubSpot CLI and Projects documentation to set up your development environment.
No action is required to maintain existing legacy public apps — they continue to function without interruption.

Helpful resources:

Questions or concerns? Join us in the Developer Community Forum for a peer-to-peer discussion.

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