WebMCP User Interaction (Human-in-the-Loop)

Before writing code

Fetch live docs:

1. Fetch https://webmachinelearning.github.io/webmcp/ for the ModelContextClient and requestUserInteraction specification
2. Web-search webmcp requestUserInteraction ModelContextClient specification for the callback API
3. Web-search site:developer.chrome.com webmcp user interaction confirmation for Chrome implementation guidance
4. Web-search webmcp human-in-the-loop agent confirmation for community patterns

Conceptual Architecture

What requestUserInteraction Does

client.requestUserInteraction(callback) is a method on the ModelContextClient object passed to every tool's execute callback. It pauses tool execution, hands control to the user (via a site-provided UI), and resumes when the user responds.

This is the primary mechanism for human-in-the-loop approval in WebMCP.

Why It Matters