---
title: approval
sidebarTitle: approval
---

# `fastmcp.apps.approval`


Approval — a Provider that adds human-in-the-loop approval to any server.

The LLM presents a summary of what it's about to do, and the user
approves or rejects via buttons. The result is sent back into the
conversation as a message, prompting the LLM's next turn.

Requires ``fastmcp[apps]`` (prefab-ui).

Usage::

    from fastmcp import FastMCP
    from fastmcp.apps.approval import Approval

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


## Classes

### `Approval` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/apps/approval.py#L49" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A Provider that adds human-in-the-loop approval to a server.

The LLM calls the ``request_approval`` tool with a summary and
optional details. The user sees an approval card with Approve and
Reject buttons. Clicking either sends a message back into the
conversation (via ``SendMessage``), triggering the LLM's next turn.

The message appears as if the user sent it, so the LLM sees
something like ``'"Deploy v3.2 to production" is APPROVED'``.

Example::

    from fastmcp import FastMCP
    from fastmcp.apps.approval import Approval

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

Customized::

    Approval(
        title="Deploy Gate",
        approve_text="Ship it",
        approve_variant="default",
        reject_text="Abort",
        reject_variant="destructive",
    )

