{
  "type": "string",
  "description": "Source of an agent credit grant (fiat-only, no on-chain deposits)",
  "enum": [
    "fiat_purchase",
    "signup_bonus",
    "payment_method_bonus",
    "daily_claim",
    "referral_reward",
    "admin_grant",
    "promo_code",
    "tier_bonus",
    "refund",
    "publisher_payout"
  ]
}