Previously, HubSpot released a beta allowing users to utilize private apps and projects to build a custom card with JSON-based components for UI extensibility within the CRM development tools.
However, a new custom card UI extension with React components will replace the JSON custom cards within the CRM development tools. This change results from the feedback and use cases end users shared from the CRM development tools public beta that helped define this new chapter for custom cards and UI extensibility at HubSpot.
Starting September 2023, no new HubSpot accounts can create custom card extensions with JSON. Any existing cards with JSON-based components will continue to work and not break; however, any new beta enrollment for CRM development tools will be React only by default, and any new JSON cards uploaded will be blocked. In addition, all supporting documentation and code samples for JSON have been replaced with React-based custom cards.
Note: Any public apps built via an app developer account, which includes Marketplace Apps will not be affected.
What does this mean for developers?
The recent React custom card UI extension change will offer more flexibility and interactivity through an enhanced front end. This will allow developers to achieve better development results while also enabling more complex customizations. Previously, the system relied solely on backend and serverless-driven approaches. However, with the introduction of UI extensions, developers can now create front-end experiences using React while still being able to use HubSpot’s serverless functions when necessary. This approach provides developers access to the active ecosystem and open-source tooling that React is known for.