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Fetch the complete documentation index at: https://docs.formbase.dev/llms.txt

Use this file to discover all available pages before exploring further.

Formbase stores every submission, but sometimes you want the values immediately after submit to personalize the next screen. You can do this in two ways:
  • Use the existing form data in the browser
  • Submit from the server and use the JSON response
1

Client-side data (fastest)

Use the values you already have in the browser and redirect with state or query params.
const formData = new FormData(formElement);

const response = await fetch('https://formbase.dev/s/YOUR_FORM_ID', {
  method: 'POST',
  body: formData,
  redirect: 'manual',
});

if (response.status === 303 || response.ok) {
  sessionStorage.setItem('lastSubmission', JSON.stringify({
    email: formData.get('email'),
  }));
  window.location.href = '/thanks';
}
On your thank-you page, read sessionStorage and render a personalized message.
2

Server-side data (structured)

Submit from your server and return the JSON payload to your client.
const response = await fetch('https://formbase.dev/s/YOUR_FORM_ID', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({ email: '[email protected]' }),
});

const result = await response.json();
// result.data contains the submitted object
This is the best option when you need a reliable JSON response.
Browser requests receive a redirect instead of JSON. Use a server action or API route if you need the response body.