Add toolbox playground support for viewing MCP Apps UI resources
Author: pjmsmithgoogleCreated Sep 16, 2026Updated Sep 17, 2026
Labelstype: feature requestpriority: p2
Prerequisites
- Search the current open issues
What are you trying to do that currently feels hard or impossible?
MCP Apps support was recently added to mcp-toolbox but currently the playground does not support displaying the UI resource in a sandboxed iframe.
Suggested Solution(s)
Add support for initializing and communicating with a MCP Apps (SEP-1865) compliant, sandboxed iframe. Indicate via a badge that a tool supports returning UI resources.
Alternatives Considered
No response
Additional Details
No response
Source: googleapis/mcp-toolbox