WebMCP in TrialStack Studio

WebMCP gives a compatible browser agent structured tools for the TrialStack Studio page you are viewing. It helps the agent understand the page and work with visible forms more reliably than interpreting buttons and fields from the page layout alone.

TrialStack provides WebMCP as a progressive enhancement. Studio works as usual when the browser does not support WebMCP.

WebMCP and Catalyst MCP

WebMCP complements the Model Context Protocol (MCP) connection provided by TrialStack Catalyst. They serve different contexts:

Interface	Context	Authority
WebMCP	The current signed-in Studio page in a compatible browser	Can describe and navigate the visible view. It can draft or validate a visible form, but it cannot save it.
Catalyst MCP	A supported AI app connected to TrialStack through the Catalyst service	Can read organization-scoped data and prepare permitted changes. Applying a change requires a separate approval.

WebMCP uses your existing Studio session. It does not create a separate remote connection or give the browser agent broader TrialStack access.

Requirements

To use the tools:

• Open TrialStack Studio in a browser that supports WebMCP.
• Sign in and open the view you want the agent to work with.
• Use a browser agent or inspection tool that can discover WebMCP tools.

WebMCP is currently an experimental web platform capability. Chrome provides it through an origin trial and a local testing flag. See Chrome’s WebMCP documentation for current browser availability.

Available tools

The tools change with the current route and visible content.

Tool	What it does	What it cannot do
describe_current_view	Summarizes the page title, breadcrumbs, visible sections, form capabilities, and canonical destinations.	Return entered form values or record identifiers.
navigate_workspace	Opens a destination from TrialStack’s canonical workspace navigation.	Navigate to an arbitrary URL.
focus_view_section	Scrolls to and focuses a visible section with a stable anchor.	Focus a hidden or unavailable section.
draft_form_changes	Applies partial changes to the active visible schema-driven form.	Submit or persist the form.
validate_form	Runs the form’s existing validation and returns bounded issue summaries based on field labels.	Weaken or replace TrialStack validation.
open_form_review	Opens the existing review and justification dialog when the form supports that step.	Confirm the dialog, submit changes, or persist data.

Form tools are available only when a supported form is visible. A visible modal or drawer form takes priority over the main page form. Hidden, disabled, read-only, or unmounted fields are not exposed.

Draft and review a form

A typical browser-agent workflow keeps the final decision with you:

1. Ask the agent to describe the current view.
2. Ask it to draft specific changes in the visible form.
3. Ask it to validate the draft.
4. Review the visible values and validation messages in Studio.
5. Ask it to open the review dialog when that tool is available.
6. Check the justification and submit the change yourself.

For example:

Describe this TrialStack view. Draft the milestone details from our discussion,
then validate the form. Do not submit or persist anything.

Drafting updates only the browser’s local form state. Existing React Hook Form and schema validation remain authoritative. TrialStack’s normal save, review, permission, versioning, and audit behavior still applies when you submit.

How form fields are described

TrialStack derives the WebMCP input contract from the same metadata used to render the form. The contract can include field labels, descriptions, placeholders, allowed options, nested fields, conditional visibility, and array-table definitions.

The draft contract accepts partial input so the agent can change only the fields you requested. Unknown, hidden, and read-only fields are rejected. The complete form must still pass its existing validation before review.

Safety boundaries

• Tools are registered only on signed-in Studio routes. Public and authentication routes expose none.
• Tools are limited to the same origin. TrialStack does not enable cross-origin iframe access.
• Route changes and unmounts remove stale tools before the next view registers its tools.
• No WebMCP tool can save, approve, or persist a form.
• Tool telemetry requires analytics consent. It records lifecycle status, duration, tool name, and route family. It does not record arguments, field values, record identifiers, or validation contents.

AI output remains a proposal until you review and submit it through the relevant TrialStack workflow.

Troubleshooting

No tools are available

Confirm that you are signed in to Studio and that the browser currently supports WebMCP. Reload the page after enabling a browser flag or installing an updated browser build.

Form tools are missing

Open the form you want to edit. Some views have no schema-driven form. Create forms or direct-submit forms may expose drafting and validation without the review tool because they do not have a separate review-only step.

A drafted field is rejected

Ask the agent to describe the current view again. The field may be hidden, read-only, conditionally unavailable, or outside the active modal or drawer.

Tools changed after navigation

This is expected. WebMCP reflects the current visible route and form rather than retaining tools from a previous page.