What's New: An Improved Flow Guided Start

September 23, 2026   |  Joe Bottigliero

Starting a Globus Flow from the web application can be done one of two ways: using the Advanced raw payload editor, or using a rendered form — the Guided start. This form is rendered from a JSON Schema provided by the flow author (learn more in: How to Create an Input Schema). In order to accurately render the full range of what JSON Schema can express, we’ve rebuilt the Guided start form from the ground up.

Accurate Schema Rendering

One of the first things you may notice is that the form now more accurately reflects what the flow’s input schema describes. The Legacy form sometimes accommodated schemas that were incomplete or had errors, silently hiding issues or presenting fields in a way that didn’t match the schema’s intent. If you notice that a flow’s Guided Start looks different than it used to, that’s likely why: the new implementation renders the schema correctly, and the old one didn’t.

More Input Types

The Legacy form handled the basics, but the new implementation better understands and supports the full range of what JSON Schema can express, as examples:

  • Booleans render as a toggle or checkbox.
  • Numbers and integers get numeric inputs with appropriate constraints.
  • Arrays and objects render as structured, interactive fields.
  • Nullable fields (fields that accept a value or nothing) are handled gracefully, with a clear way to leave them empty.

If a flow author declares that a field can be one of several types — say, a string or a number — the form lets you choose which type to provide and adjusts the input accordingly.

New Standard Formats

JSON Schema supports a format keyword that hints at what kind of value a field expects, beyond just its type. The new form renders dedicated inputs with user-friendly control for the following identified format values:

Format What you get
date A date picker
time A time picker
date-time A combined date and time picker
email An email-optimized input
uri A URL-optimized input
data-url A file upload widget

Enhancing Globus-Specific Formats

The form has always supported custom Globus fields — like collection and principal (identity/group) search — the user experience of these fields has been improved and we’ve added additional formats.

  • Improved
    • Collection (globus-collection)
      • Added ability to filter results by entity type and scope.
      • Improved file browser user experience.
  • New
    • Compute Endpoint Search (globus-compute-endpoint)

Validation as You Go

The form validates your inputs in real time as you fill it out. If a field has an issue, you’ll see the error immediately, before you click Start Run.

Improved Identification of Hidden Errors

In addition to inline validation, we’ve included a way to view all input errors associated with the form. This can help identify properties set in the input schema that are not rendered to UI controls that are preventing the submission. More often than not, this is an error in the schema definition itself, but could also be intentional if you don’t expect users to start the flow from the web application.

Tag Suggestions

When labeling a run, the tags field now suggests tags you’ve used recently and your most used tags, making it easier to keep your runs organized consistently.

Optional Label

We’ve updated the label field to be optional, this better reflects the requirements of the Flows service and opens up new usage paths.

Pre-Fill from the URL

The Guided form now supports using URL parameters to pre-fill form inputs . If someone shares a link to a flow with specific inputs already set, the form will open with those values filled in — useful for sharing a common configuration or building guided workflows.

Flows IDE Integration

The Flows IDE Input Schema UI now uses the same form rendering code that we use in the web application, so the schema preview now more accurately reflects the Guided start experience.

Deprecating the Legacy Form

The improvements outlined above support our decision to deprecate what is now the Legacy form and we will no longer be addressing issues in the Legacy form as of 9/23/2026. We recognize that more strict adherence to JSON Schema may cause issues with existing flows. To allow authors time to address issues, without fully disrupting user workflows, the Legacy form will be available until January 1st 2027.


We hope these updates make running flows a smoother experience and as always, feel free to reach out to support@globus.org if you have any questions.