{
  "$comment": "Declare every channel once. utm_source and utm_medium are never invented at call time.",
  "channels": {
    "newsletter": { "utm_source": "newsletter", "utm_medium": "email" },
    "x": { "utm_source": "x", "utm_medium": "social" },
    "youtube": { "utm_source": "youtube", "utm_medium": "video" },
    "github": { "utm_source": "github", "utm_medium": "referral" },
    "organic_search": { "utm_source": "google", "utm_medium": "organic" }
  },
  "owned_domains": ["example.com"],
  "checkout_hosts": ["buy.stripe.com", "payhip.com", "gumroad.com"]
}