curl "https://app.talkover.ai/api/v1/credits/balance" \
  -H "Authorization: Bearer your_user_session_token"

{
  "success": true,
  "data": {
    "balance": 250.00,
    "currency": "USD",
    "auto_topup_enabled": true,
    "as_of": "2024-01-15T19:30:00Z"
  }
}