HubSpot is sunsetting serverless functions built in the design manager, and Node.js 20 and earlier for workflow custom code actions. All of these run on runtime versions that no longer receive security updates. To keep your website features and workflows working, move your design manager serverless functions to developer projects, and update your custom code actions to Node.js 24. To make migration easier we've provided an AI prompt for design manager functions and a Breeze Assistant powered update capability for custom code actions.
What's changing
Design manager serverless functions
Serverless functions uploaded to the design manager and served from /_hcms/api/ run on Node.js 18 or 20, which HubSpot can't upgrade. HubSpot is sunsetting them in three stages:
- Starting November 3, 2026, you can no longer create new design manager serverless functions. You can still edit existing functions until November 17.
- Starting November 17, 2026, you can no longer edit existing design manager serverless functions, including staging and deploying serverless packages through the design manager private beta. Existing functions keep running.
- Starting February 1, 2027, design manager serverless functions stop running, and requests to
/_hcms/api/endpoints fail.
HubSpot can't migrate your functions automatically, because each function's code and the pages that call it are unique to your site. Migrating means rebuilding each function in a developer project, where it's served from /hs/serverless/ instead of /_hcms/api/, and updating the templates, modules, and settings that call it.
The design manager serverless functions migration guide walks you through the process, from finding every function and every page that calls it to switching over one function at a time with a tested rollback path. It also includes a prompt you can give to an AI coding agent to carry out the migration with your approval at each step.
Which developer projects platform version to use
Functions in developer projects run on the Node.js version set by the project's platformVersion, and they get Node.js security updates automatically. Build new projects on the current platform version, 2026.09. Projects already on 2026.03 and 2026.09 run Node.js 24 and don't need to be migrated at this time. See developer platform versioning.
If you already have serverless functions in a developer project on platform version 2023.1, 2023.2, or 2025.1, those functions run on Node.js 18 or 20 and don't get security updates. Upgrade the project with hs project migrate, then redeploy it. Builds and deploys on those versions are already blocked. Learn how to migrate an app to the latest platform version.
Workflow custom code actions
Custom code actions in workflows can now use Node.js 24, which receives security updates. Existing custom code actions that use Node.js 16 or 20 keep running. Node.js 16 is already deprecated, so you can't save changes to a Node.js 16 action until you switch it to a newer version.
- Starting November 3, 2026, you can no longer create new Node.js 20 custom code actions.
- Starting November 17, 2026, you can't save changes to existing Node.js 20 actions either.
Upgrading isn't only a runtime change. Node.js 24 doesn't support callback-style handlers, and the libraries available to your code have new versions, so you'll need to update and test each action. Breeze can update the custom code actions in a workflow for you.
The guide to upgrading custom code actions to Node.js 24 walks you through finding the workflows that use them, updating and testing your code, checking library changes, and rolling back if you need to.
When is it happening?
- Now (November 3, 2026): you can no longer create new design manager serverless functions or new Node.js 20 custom code actions. Node.js 24 is available for custom code actions, and both migration guides are live.
- November 17, 2026: you can no longer edit existing design manager serverless functions or existing custom code actions that use Node.js 20, as is already the case for Node.js 16. Existing functions and actions keep running.
- February 1, 2027: design manager serverless functions stop running.
Questions or comments? Join us in the developer forums.