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Special fields start with _ and control form behavior. They are not stored in submission data.

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_next - Redirect URL

Redirect users after successful submission: 
<input type="hidden" name="_next" value="https://yoursite.com/thanks">
This overrides the redirect URL set in form settings.

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_subject - Email Subject

Customize the notification email subject: 
<input type="hidden" name="_subject" value="New inquiry from website">

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With Variables

Include form data in the subject: 
<input type="hidden" name="_subject" value="Contact from {{ name }}">

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_replyto - Reply-To Address

Set the Reply-To header for notification emails: 
<input type="hidden" name="_replyto" value="[email protected]">
Or use a form field: 
<input type="email" name="_replyto" placeholder="Your email" required>
If you have a field named email, it’s automatically used as Reply-To. Use _replyto to override this.

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_gotcha - Honeypot

Built-in honeypot field for spam protection: 
<input type="text" name="_gotcha" style="display:none" tabindex="-1" autocomplete="off">
If this field has a value, the submission is marked as spam.

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_cc - Carbon Copy

Send a copy of the notification to additional emails: 
<input type="hidden" name="_cc" value="[email protected],[email protected]">

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Example: Complete Form

<form action="https://spike.ac/api/f/YOUR_FORM_SLUG" method="POST">
  <!-- Special fields -->
  <input type="hidden" name="_next" value="https://yoursite.com/thanks">
  <input type="hidden" name="_subject" value="New contact from {{ name }}">
  <input type="text" name="_gotcha" style="display:none" tabindex="-1">
  
  <!-- Regular fields -->
  <input type="text" name="name" placeholder="Name" required>
  <input type="email" name="email" placeholder="Email" required>
  <textarea name="message" placeholder="Message" required></textarea>
  
  <button type="submit">Send</button>
</form>

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Field Reference

FieldTypeDescription
_nextURLRedirect URL after submission
_subjectStringEmail subject (supports {{ variables }})
_replytoEmailReply-To address for notifications
_gotchaStringHoneypot field (should be empty)
_ccEmailsAdditional notification recipients
_optinBooleanMarketing opt-in flag

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Notes

  • Special fields are not stored in submission data
  • They only affect form behavior
  • Field names are case-sensitive
  • You can use hidden inputs or regular inputs