curl https://api.stablegenius.co/v1/transactions/txn_def456 \
  -H "Authorization: Bearer sk_test_abc123"

{
  "id": "txn_def456",
  "object": "transaction",
  "payment_intent_id": "pi_xyz789",
  "merchant_id": "mer_abc123",
  "status": "confirmed",
  "amount": 4.50,
  "currency": "usd",
  "net_amount": 4.455,
  "fee": 0.045,
  "fee_rate": 0.01,
  "chain": "base",
  "token": "USDC",
  "tx_hash": "0xabc123def456789012345678901234567890abcdef",
  "block_number": 12345678,
  "sender_address": "0x9876543210fedcba9876543210fedcba98765432",
  "payment_address": "0x1a2b3c4d5e6f7890abcdef1234567890abcdef12",
  "settlement_status": "pending",
  "confirmed_at": "2026-04-01T20:00:12Z",
  "metadata": {
    "order_id": "order_456",
    "terminal_id": "pos_01"
  }
}