Attributes

Custom element

<formbuilder-form form="…" lang="nl" isolate="shadow"></formbuilder-form>

Attribute	Default	Meaning
form	required	Form id. The uuid, not the slug, so a pasted snippet survives a rename
lang	the form’s base	Render a specific translation
api	the script’s origin	Endpoints on a different host
isolate	auto	shadow seals the form from page CSS

Object values are properties, not attributes:

el.prefill = { email: 'ada@example.com' };

Loader

Everything is data-fb-*, on the container for inline mode or on the script tag for overlay modes.

Attribute	Default	Meaning
data-fb-form	required	Form id
data-fb-mode	inline	inline, popup, drawer, button
data-fb-isolate	auto	shadow, iframe, none
data-fb-lang	the form’s base	Translation
data-fb-api	the script’s origin	Endpoints elsewhere
data-fb-field-<name>	none	Prefill a field
data-fb-prefill-url	1	Read prefills from the page query string
data-fb-height	auto	Fixed iframe height
data-fb-trigger	click	click, load, delay, scroll, exit
data-fb-trigger-selector	none	What to bind the trigger to
data-fb-delay	5000	ms, for delay
data-fb-scroll	50	percent, for scroll
data-fb-once	session	session, forever, never
data-fb-position	right	Drawer side
data-fb-size	md	Overlay width

data-fb-api is only needed when the bundle and the endpoints are on different hosts. Otherwise the loader takes the origin of its own src, which is right in every ordinary deployment.