---
title: form
sidebarTitle: form
---

# `fastmcp.apps.form`


FormInput — a Provider that collects structured input from the user.

Define a Pydantic model for the data you need, and ``FormInput``
generates a form UI. The user fills it out, the submission is
validated, and an optional callback processes the result.

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

Usage::

    from pydantic import BaseModel
    from fastmcp import FastMCP
    from fastmcp.apps.form import FormInput

    class ShippingAddress(BaseModel):
        street: str
        city: str
        state: str
        zip_code: str

    mcp = FastMCP("My Server")
    mcp.add_provider(FormInput(model=ShippingAddress))


## Classes

### `FormInput` <sup><a href="https://github.com/PrefectHQ/fastmcp/blob/main/fastmcp_slim/fastmcp/apps/form.py#L88" target="_blank"><Icon icon="github" style="width: 14px; height: 14px;" /></a></sup>


A Provider that collects structured input via a Pydantic model.

Define a model for the data you need, and ``FormInput`` generates
a form from it using ``Form.from_model()``. Field types, labels,
descriptions, and validation are all derived from the model.

Optionally provide an ``on_submit`` callback to process the
validated data. The callback receives a model instance and returns
a string that goes back to the LLM. Without a callback, the
validated JSON is sent directly.

Example::

    from pydantic import BaseModel
    from fastmcp import FastMCP
    from fastmcp.apps.form import FormInput

    class Contact(BaseModel):
        name: str
        email: str

    mcp = FastMCP("My Server")
    mcp.add_provider(FormInput(model=Contact))

With a callback::

    def save_contact(contact: Contact) -> str:
        db.insert(contact.model_dump())
        return f"Saved {contact.name}"

    mcp.add_provider(FormInput(model=Contact, on_submit=save_contact))

