Choice - Fastmcp — ContextQMD

import { VersionBadge } from '/snippets/version-badge.mdx'

Choice lets the LLM present a set of options as clickable buttons instead of asking the user to type a response. The selection flows back into the conversation as a message, giving the LLM clean structured input.

python

from fastmcp import FastMCP
from fastmcp.apps.choice import Choice

mcp = FastMCP("My Server")
mcp.add_provider(Choice())

This registers a single tool:

Tool	Visibility	Purpose
`choose`	Model	Shows a card with clickable options, sends the selection back as a message

The LLM calls choose with a prompt and a list of options. The user sees a card with one button per option. Clicking one sends a message back into the conversation:

"Which deployment strategy?" — I selected: Blue-green

<Note> This is an advisory interaction, not an enforcement mechanism. The conversation isn't blocked while the card is open — the user can keep typing, and the LLM could proceed without waiting. The tool description instructs the LLM to stop and wait for the "I selected:" response, but for hard enforcement, implement selection logic server-side. </Note>

Configuration

The constructor sets defaults; the LLM can override title per-call.

python

Choice(
    name="Choice",             # App name
    title="Choose an Option",  # Default card heading
    variant="outline",         # Button style for all options
)

The LLM provides the options per-call:

python

choose(
    prompt="What should we have for lunch?",
    options=["Pizza", "Tacos", "Ramen", "Salad"],
    title="The Important Questions",
)

How it works

Each option renders as a full-width button in a vertical stack. When the user clicks one:

SendMessage pushes the selection into the conversation as a user message
SetState("decided", True) replaces the buttons with "Response sent."

The tool description instructs the LLM to stop and wait for the "I selected:" message before proceeding with whatever the user chose.