<form action method>: the request your backend receives

Three attributes shape the HTTP request

<form action="/api/signup" method="post" enctype="application/x-www-form-urlencoded">
  <input name="email" type="email" />
  <input name="password" type="password" />
  <button type="submit">Sign up</button>
</form>

• `action` — where the form POSTs. Relative or absolute URL. Defaults to the current page.
• `method` — get (default, params in URL) or post (body). For mutations, use post. For searches, use get.
• `enctype` — only matters for POST:

- application/x-www-form-urlencoded (default) — email=anna%40example.com&password=…

- multipart/form-data — required when one or more inputs are <input type="file">

- text/plain — never use this, it's only for debugging

What FastAPI sees

For <form method="post"><input name="email" value="anna@example.com"></form>, your FastAPI endpoint:

@app.post("/api/signup")
async def signup(email: str = Form()):
    return {"got": email}

The name="email" is the Pydantic field name. If you change name="user_email" on the input, FastAPI's Form(alias="user_email") is what catches it.

GET vs POST visibility

get puts data in the URL (/search?q=python) — bookmarkable, sharable, in browser history. post puts data in the body — invisible in URL, not in history, not bookmarked. Passwords ALWAYS POST.