What you receive

Before you wire formbuild.io into your backend, here's exactly what reaches your server — by webhook, and by API. Every field name below is the field's name attribute, so a form with email and message fields produces data.email and data.message.

The webhook payload

When someone submits your form, we send an HTTP POST to each configured webhook URL with this JSON body:

{
  "event": "form.submission",
  "formName": "Contact form",
  "submittedAt": "2026-05-30T12:34:56.789Z",
  "data": {
    "email": "jordan@acme.com",
    "message": "Loved the demo — can we get SSO?"
  }
}

Request headers

We send Content-Type: application/json and User-Agent: formbuild.io/1.0. When a signing secret is configured, we also send an X-Formbuild-Signature header so you can confirm the request is genuinely from us. See Webhook signing and delivery for the header table and a copy-paste verification example — no need to duplicate it here.

A schema for your form

From your form's Installation tab, the What you'll receive panel shows this same sample payload built from your live fields, plus a downloadable JSON Schema you can pipe straight into your own validation or type generation. Required fields, email formats, and select options are all reflected in the schema.

Reading responses over the API

Prefer to pull responses instead of receiving them? Authenticate with an API key (Authorization: Bearer formbuild_live_...) and call:

GET /api/v1/forms/{id}/submissions

The response is paginated:

{
  "data": [
    {
      "id": "sub_...",
      "data": { "email": "jordan@acme.com", "message": "..." },
      "isSpam": false,
      "createdAt": "2026-05-30T12:34:56.789Z"
    }
  ],
  "meta": { "total": 128, "limit": 50, "offset": 0, "hasMore": true }
}

Use limit (max 100) and offset query parameters to page through results. See API and submissions for the full endpoint reference.