Embedding forms

Point a website form at a capture hook URL so submissions become leads automatically.

By the end of this page your website form will post straight into SmileLine — no backend code on your side.

Before you start

You need a capture hook and its endpoint URL. Create one under Settings → Capture hooks and copy the URL from the list — it looks like https://api.smileline.io/capture/YOUR_TOKEN. See Capture hooks.

The endpoint accepts application/json, application/x-www-form-urlencoded and multipart/form-data. URL query parameters are merged underneath the body, so pixel-style integrations can ride the query string alone. File uploads are ignored.

Point your form at the hook

A classic form post. The browser navigates to the endpoint's raw JSON response, so prefer the fetch variant to keep visitors on your page:

<form action="https://api.smileline.io/capture/YOUR_TOKEN" method="POST">
  <input name="first_name" placeholder="First name" />
  <input name="last_name" placeholder="Last name" />
  <input name="email" type="email" placeholder="Email" required />
  <input name="phone" type="tel" placeholder="Mobile" />
  <input name="treatment" type="hidden" value="invisalign" />
  <textarea name="message" placeholder="How can we help?"></textarea>
  <button type="submit">Request a consultation</button>
</form>

Submit in the background and show your own thank-you message. The endpoint allows cross-origin requests, so this works from any website:

const form = document.querySelector("#enquiry-form");
form.addEventListener("submit", async (event) => {
  event.preventDefault();
  const response = await fetch(
    "https://api.smileline.io/capture/YOUR_TOKEN",
    {
      method: "POST",
      headers: { "Content-Type": "application/json" },
      body: JSON.stringify({
        first_name: form.first_name.value,
        last_name: form.last_name.value,
        email: form.email.value,
        phone: form.phone.value,
        treatment: "invisalign",
        message: form.message.value,
      }),
    },
  );
  if (response.ok) showThankYou();
});

Test from the command line before wiring up the website:

curl -X POST "https://api.smileline.io/capture/YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"first_name":"Amelia","email":"amelia@example.co.uk","phone":"+447700900123"}'

A successful capture answers 201 with {"ok":true} — and the lead appears on the Today page in real time.

Which fields are understood

Field names are set per hook in its Field mapping — the left column below shows the defaults a new hook starts with. Rename them in the hook to match whatever your form already sends.

Default field name	Fills
`first_name`	Patient first name
`last_name`	Patient last name
`email`	Patient email
`phone`	Patient mobile number
`treatment`	Matched against a treatment's slug (see Settings → Treatments); unknown values fall back to the hook's Default treatment
`location`	Matched against a location id, then a case-insensitive location name; unknown values fall back to the hook's Location — one form can serve every site
`message`	Saved as a note on the patient timeline

Rules worth knowing:

A valid email or phone is required. A submission with neither (after mapping) is rejected with 400.
Nothing is thrown away. Fields that aren't mapped are kept verbatim on the lead's capture record and shown under Additional information on the lead panel.
Bad values degrade, they don't fail. An unparseable email or phone is kept in the raw capture record while the other contact detail carries the lead.
Duplicates attach, they don't multiply. If the email or phone matches an existing patient, the enquiry is attached to them instead of creating a duplicate.

Attribution is automatic

Do not map marketing parameters — they're extracted automatically into the lead's attribution record: utm_* parameters, ad-platform click ids (gclid, fbclid, msclkid, ttclid and many more), landing_url, referrer and user_agent. Just make sure your form forwards the page's query parameters (or posts them alongside the fields). See Attribution.

Rich integrations (e.g. Zapier or a custom tracking script) can also post a structured _sl envelope with visitor context and an event_id idempotency key — re-posting the same event_id never creates a duplicate. The full envelope shape is documented in the API reference under the Capture group at /reference.

Responses

Status	Meaning
`201`	Captured — body is `{"ok":true}`
`400`	Invalid body, or no valid email/phone after mapping
`404`	Unknown, paused or archived token
`429`	Rate limited — retry after the number of seconds in the `Retry-After` header

A 404 from a URL that used to work usually means the hook was paused, archived, or its token was regenerated. Check Settings → Capture hooks.