en How to Add HTML Output to a Tool

How to Add HTML Output to a Tool

Turn a tool's raw JSON response into a rendered HTML view, for AI clients that can display rich output instead of plain data.

Prerequisites: a tool that already returns a working JSON response — test it once before adding a template.

Steps

1. Open the server and go to its Tools tab, then open the tool you want to add HTML output to.

   Open the capture server to document Add HTML Output to a Tool.

   

2. Find the HTML output template section and enable it.

3. Fill in test argument values and run "Test & map response" — Arthur calls the real endpoint and shows you the actual response.

   Open the Tools tab, which contains the interface used by this procedure.

   

4. Click "Use response schema" to auto-extract the fields from that response as template variables — scalar fields become {{field}}, list fields become {{#each items}}...{{/each}} blocks.

5. Write your HTML in the editor, using the extracted variables. Switch to the Preview tab to see it rendered live against your test data.

6. Save.

   Bring the New tool panel into the screenshot viewport.

   

Confirm it worked

The Preview tab shows your real data rendered as HTML, not raw JSON. When the tool is called by an AI client, its output is now the rendered HTML instead of the plain JSON body.

Good to know

• The editor has a full-screen mode if you're writing a longer template.
• The same Handlebars templating approach is used for dynamic Resources — if you've built one HTML template, the other works the same way.

Related

• Dynamic Tools
• How to Test a Tool