Yes — use an autoresponder with a confirmation link, or forward via webhook to your ESP.

Do I need the json-enc extension?

Yes, to send a JSON body. Without it htmx sends form-urlencoded, which FormLoom also accepts.

How do I show the response?

Use `hx-swap` to replace the form (or a target) with FormLoom's response.

htmx newsletter signup form

A single-field email capture for your mailing list.

Recommended fields

Field	Type	Required
email	email	Yes

The code

Use `hx-post`, `hx-ext="json-enc"`, and an `hx-headers` attribute for `Accept: application/json`. Swap the response into the page.

htmx (hx-post + json-enc)

contact.html

<!-- Include htmx + the json-enc extension -->
<form
  hx-post="https://formloom.vercel.app/api/submit/YOUR_ACCESS_KEY"
  hx-ext="json-enc"
  hx-swap="outerHTML"
  hx-headers='{"Accept": "application/json"}'
>
  <label>
    Email
    <input type="email" name="email" required />
  </label>
  <!-- honeypot: bots fill this, humans don't see it -->
  <input type="checkbox" name="botcheck" style="display:none" tabindex="-1" autocomplete="off" />
  <button type="submit">Send</button>
</form>

Plain HTML (no JavaScript)

contact.html

<form action="https://formloom.vercel.app/api/submit/YOUR_ACCESS_KEY" method="POST">
  <label>
    Email
    <input type="email" name="email" required />
  </label>
  <!-- honeypot: bots fill this, humans don't see it -->
  <input type="checkbox" name="botcheck" style="display:none" tabindex="-1" autocomplete="off" />
  <button type="submit">Send</button>
</form>

@formloom/client (typed SDK)

submit.ts

// npm i @formloom/client
import { createForm } from "@formloom/client";

type Contact = {
  email: string;
};

const form = createForm<Contact>("YOUR_ACCESS_KEY");

// End-to-end typed: TS errors if you send the wrong shape.
const { success, message } = await form.submit({
  email: form.email.value,
});

Tips

Keep it to one field — email only — for the highest conversion.
Wire an autoresponder to send a welcome / double-opt-in email.

FAQ

Usually not — email-only forms convert best. Collect the name later in your welcome email if you need it.