This is an example data format for a new custom event that is received and a POST request as JSON sent to your Webhook URL.

{
  "trigger": "new",
  "lead_id": 153928,
  "user_id": "51497-af17340d-62b8-3044-423f-3dc754e621c2",
  "lead_type": "Custom Event",
  "lead_status": "Unique",
  "lead_analysis": {  
   "Keyword Detection": "buy,quote,test",  
   "Lead Summary": "The customer was looking to purchase call tracking services. The agent assisted them with setting up an account.",  
   "Intent Detection": "The customer wanted to purchase services.",  
   "Sentiment Detection": "Positive",  
   "Topic Detection": "call tracking,purchase,sign up"  
  },
  "last_updated": "2016-01-25T17:18:20Z",
  "date_created": "2016-02-01T14:09:01Z",
  "quotable": "Not Set",
  "quote_value": null,
  "sales_value": 50,
  "spotted_keywords": "buy,quote",
  "lead_score": 50,
  "lead_state": "Completed",
  "profile": "My Profile",
  "profile_id": 51497,
  "account": "My Account",
  "account_id": 27313,
  "lead_url": "https://www.whatconverts.com/contact",
  "landing_url": "https://www.whatconverts.com/",
  "operating_system": "iOS 12",
  "browser": "Chrome Mobile 71",
  "device_type": "Smartphone",
  "device_make": "Apple iPhone",
  "event_category": "Lead",
  "event_action": "New Signup",
  "event_label": "Click",
  "additional_fields": {
    "full_name": "John Doe",
    "email_address": "hello@whatconverts.com"
  },
  "lead_source": "google",
  "lead_medium": "cpc",
  "lead_campaign": "lead generation",
  "lead_content": "new ad",
  "lead_keyword": "generating leads",
  "ip_address": "107.210.21.188",
  "notes": "This is a new lead!",
  "contact_name": "Jeremy Helms",
  "contact_company_name": "Call Tracking Company",
  "contact_email_address": "hello@whatconverts.com",
  "contact_phone_number": "+17044695324",
  "email_address": "hello@whatconverts.com",
  "phone_number": "+17044695324",
  "city": "Charlotte",
  "state": "NC",
  "zip": "28226",
  "country": "US",
  "field_mappings": {
    "Company Name": "Call Tracking Company",
    "Contact Person": "Jeremy Helms",
    "Email": "hello@whatconverts.com",
    "Phone Number": "(704) 469-5324"
  },
  "gclid": "CLibmtmqpNICFcSfGwodQbUAvg",
  "msclkid": "25d83debf85f146b8f1d66a754c6a56c",
  "unbounce_page_id": "f8e32bbc-e1a1-2c5b-b4d3-c6289c8e33b",
  "unbounce_variant_id": "b",
  "unbounce_visitor_id": "107.210.21.1881565955056416071",
  "salesforce_user_id": "15228103840",
  "roistat_visit_id": "wqeOuWjfeIUQdd122casdLK",
  "hubspot_visitor_id": "5a72d290d2d21865a693f14bcf710fed",
  "facebook_browser_id": "fb.1.1621529626600.927228660",
  "facebook_click_id": "fb.1.1621529626598.IwAR1yDeb6_5RRDGD3fTthh9cPoaqhLYYyDFLN-LolvQwaMAPMhGRljDj-POc",
  "google_analytics_client_id": "1017418163.1594157791",
  "vwo_account_id": "512835",
  "vwo_experiment_id": "2",
  "vwo_variant_id": "2",
  "vwo_user_id": "D4A14C3EFD6DB2A51749E1A931BE96B44",
  "duplicate": false,
  "spam": false
}

For additional information on setting up webhooks see Webhooks.