curl --request GET \
  --url https://api.example.com/v1/opportunities/{opportunity_id}

{
  "data": {
    "id": "opp_abc123",
    "account_id": "acc_def456",
    "name": "Acme Corp - Enterprise License",
    "owner": {
      "id": "usr_abc123",
      "first_name": "Jane",
      "last_name": "Smith"
    },
    "stage": "negotiation",
    "estimated_value": {
      "currency_code": "USD",
      "amount": 5000000
    },
    "estimated_close_date": "2025-09-30",
    "summary": "Enterprise deal with strong champion. Procurement review in progress.",
    "risks": [
      "Budget constraints",
      "Competing vendor evaluation"
    ],
    "tags": [
      "High Priority"
    ],
    "last_activity_at": "2025-08-20T14:30:00Z",
    "created_at": "2025-06-01T09:00:00Z",
    "custom_field_550e8400-e29b-41d4-a716-446655440001": "outbound",
    "custom_field_6ba7b810-9dad-11d1-80b4-00c04fd430c8": "commit",
    "custom_field_f47ac10b-58cc-4372-a567-0e02b2c3d479": "Initech"
  },
  "meta": {
    "timestamp": "2026-04-21T12:00:00Z"
  }
}