Enviar desde tu servidor

Tu formulario HTML  →  tu servidor (/api/brein)  →  Brein (POST …/responses)

curl -X POST https://api.trybrein.com/api/v1/forms/frm_AbC123dEf4/responses \
  -H "Authorization: Bearer $BREIN_FORM_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"answers":{"correo":"ana@empresa.com"},"consent":{"privacy":true}}'

{ "id": "8f1c…", "status": "received" }

BREIN_FORM_KEY=frm_sk_…

<form action="/api/brein" method="post">
  <input type="text" name="nombre" placeholder="Tu nombre" />
  <input type="email" name="correo" placeholder="Tu correo de trabajo" required />
  <label>
    <input type="checkbox" name="privacy" required />
    Acepto el <a href="/privacidad">aviso de privacidad</a>
  </label>
  <button type="submit">Enviar</button>
</form>

// app/api/brein/route.ts
import { NextResponse } from 'next/server'

const BREIN_RESPONSES_URL = 'https://api.trybrein.com/api/v1/forms/frm_AbC123dEf4/responses'

export async function POST(request: Request) {
  const data = await request.formData()

  const response = await fetch(BREIN_RESPONSES_URL, {
    method: 'POST',
    headers: {
      Authorization: `Bearer ${process.env.BREIN_FORM_KEY}`,
      'Content-Type': 'application/json',
    },
    body: JSON.stringify({
      answers: {
        nombre: String(data.get('nombre') ?? ''),
        correo: String(data.get('correo') ?? ''),
      },
      consent: { privacy: data.get('privacy') === 'on' },
    }),
  })

  if (!response.ok) {
    return NextResponse.json(await response.json(), { status: response.status })
  }
  return NextResponse.redirect(new URL('/gracias', request.url), 303)
}