Querystring variables

Query parameters are appended to your FlowIframeEmbed Site URL (iframe src). The Visualforce page reads them and starts the flow in Lightning Runtime.

The base path is https://your-site.force.com/site-prefix/apex/three_levers__FlowIframeEmbed (namespaced page three_levers__FlowIframeEmbed from the three_levers package, not /FlowIframeEmbed).

Reserved parameters

Parameter	Required	Description
flow	Yes	Flow API Developer Name (for example Check_In_Dispatch).
endUrl	No	Absolute URL. When flow status is FINISHED, the parent window navigates here.
inputVars	No	Comma-separated allowlist of param names to pass into flow as String inputs. If omitted, no URL params are passed.
bg	No	Color of the iframe page body. Set this in the JavaScript widget or WordPress settings. It is not a flow input.
padding	No	Space around the flow on the iframe page body. Set this in the JavaScript widget or WordPress settings. It is not a flow input.
primary	No	Color of Next and Finish buttons. Set this in the JavaScript widget or WordPress settings. It is not a flow input. Blank keeps rust #C75B39.
primaryHover	No	Hover color of those buttons. When blank, a darker mix of primary is used. It is not a flow input.
secondary	No	Text and border of Previous buttons. When blank, dark text and a gray border stay. It is not a flow input.

scrollOffset is not in this table. It stays on the WordPress setting or the JavaScript widget. Putting it on the Site URL does nothing. Next and Previous already scroll the parent page to the top of the flow. Other buttons do not.

Those style keys change the page color, the space around the flow, and the Next, Finish, and Previous buttons. Type, field borders, and error color stay in the style block on the FlowIframeEmbed Visualforce page.

Flow input parameters

Any other query parameter is passed to the flow only if its name appears in inputVars.

Example:

https://your-site.force.com/site-prefix/apex/three_levers__FlowIframeEmbed?flow=New_Customer_Flow&inputVars=recordId,source&recordId=001xxx&source=homepage&debug=1

• recordId and source are passed.
• debug is ignored (not in inputVars).

Flow input variable API names must match parameter names case-sensitively.

Using the JavaScript widget

Set inputVars and params on window.tlFlowEmbed:

window.tlFlowEmbed = {
  embedUrl: 'https://your-site.force.com/site-prefix/apex/three_levers__FlowIframeEmbed',
  flow: 'New_Customer_Flow',
  inputVars: ['recordId', 'source'],
  params: { recordId: '001xxx', source: 'homepage' }
};

Security note

The allowlist prevents arbitrary query params from becoming flow inputs. Validate values in Flow or Apex before using them.

Legacy behavior

Older widget behavior appended all parent query params into iframe URL. That behavior is not supported on FlowIframeEmbed. List each input explicitly in inputVars.