How to add a contact form to Gatsby

import { useState, type FormEvent } from "react";

const ENDPOINT = "https://formsubmit.app/f/YOUR_FORM_ID";

export default function ContactForm() {
  const [status, setStatus] = useState<"idle" | "sending" | "success" | "error">("idle");
  const [error, setError] = useState("");
  const [renderedAt] = useState(() => Date.now());

  async function onSubmit(e: FormEvent<HTMLFormElement>) {
    e.preventDefault();
    setStatus("sending");
    const data = new FormData(e.currentTarget);
    data.set("_ts", String(renderedAt)); // helps FormSubmit's time-based spam check
    try {
      const res = await fetch(ENDPOINT, {
        method: "POST",
        body: data,
        headers: { Accept: "application/json" },
      });
      const json = await res.json();
      if (!res.ok || !json.ok) throw new Error(json.error?.message ?? "Something went wrong");
      setStatus("success");
      e.currentTarget.reset();
    } catch (err) {
      setError((err as Error).message);
      setStatus("error");
    }
  }

  if (status === "success") {
    return <p className="text-green-700">Thanks! We'll be in touch soon.</p>;
  }

  return (
    <form onSubmit={onSubmit} className="mx-auto max-w-lg space-y-5">
      <div className="space-y-1.5">
        <label htmlFor="fs-name" className="block text-sm font-medium text-gray-900">Name</label>
        <input id="fs-name" type="text" name="name" placeholder="Jane Doe" required className="block w-full rounded-lg border border-gray-300 px-3 py-2 text-sm shadow-sm focus:border-indigo-500 focus:outline-none focus:ring-2 focus:ring-indigo-500/20" />
      </div>
      <div className="space-y-1.5">
        <label htmlFor="fs-email" className="block text-sm font-medium text-gray-900">Email</label>
        <input id="fs-email" type="email" name="email" placeholder="jane@example.com" required className="block w-full rounded-lg border border-gray-300 px-3 py-2 text-sm shadow-sm focus:border-indigo-500 focus:outline-none focus:ring-2 focus:ring-indigo-500/20" />
      </div>
      <div className="space-y-1.5">
        <label htmlFor="fs-message" className="block text-sm font-medium text-gray-900">Message</label>
        <textarea id="fs-message" name="message" rows={5} placeholder="How can we help?" required className="block w-full rounded-lg border border-gray-300 px-3 py-2 text-sm shadow-sm focus:border-indigo-500 focus:outline-none focus:ring-2 focus:ring-indigo-500/20"></textarea>
      </div>
      {/* Honeypot: bots fill this in, humans never see it */}
      <input type="text" name="_gotcha" tabIndex={-1} autoComplete="off" style={{ display: "none" }} />
      {status === "error" && <p className="text-sm text-red-600">{error}</p>}
      <button type="submit" disabled={status === "sending"} className="inline-flex w-full items-center justify-center rounded-lg bg-gray-900 px-4 py-2.5 text-sm font-medium text-white hover:bg-gray-800 disabled:opacity-50">
        {status === "sending" ? "Sending…" : "Send"}
      </button>
    </form>
  );
}

import * as React from "react";
import ContactForm from "../components/ContactForm";

export default function ContactPage() {
  return (
    <main style={{ maxWidth: 560, margin: "0 auto", padding: "4rem 1rem" }}>
      <h1>Contact</h1>
      <ContactForm />
    </main>
  );
}

export const Head = () => <title>Contact</title>;