Auto-Attach Custom Form to Documents

correct. I usually attach through fusion.

Correct. Workfront doesn't have a native auto-attach for custom forms on documents the way it does for projects, tasks, and issues through queue setup or project preferences.

That said, Fusion bridges this gap cleanly. You can build a scenario that:

1. Triggers on a Document created event (Watch Events→ DOCU object type, "created")

2. Filters by the parent object type if needed (e.g., only documents added to tasks)

3. Makes an API call to attach your custom form to the document using the objectCategories endpoint

The call is essentially a POST to attach the category (form) ID to the newly created document ID. Once it's running, it's invisible to users, the form just appears on every document automatically.

The only caveat: there's a brief delay between upload and form attachment since Fusion is event-driven, so users may see a moment without the form before it populates. If that's a concern, a webhook-based trigger (rather than polling) tightens that window considerably. I have a scenario that does exactly this. Thanks

In addition to Fusion, if you have the newest version of business rules, you can do it with business rules.

https://experienceleague.adobe.com/en/docs/workfront/using/administration-and-setup/set-up-wf/configure-system-defaults/business-rules#scenarios-for-business-rule-automation