{
  "fields": [
    {"name": "first_name",   "dtype": "string",  "required": true,  "aliases": ["First Name", "fname"]},
    {"name": "last_name",    "dtype": "string",  "required": true,  "aliases": ["Last Name", "lname"]},
    {"name": "email",        "dtype": "string",  "required": true,  "aliases": ["EmailAddr", "Email", "email_address"]},
    {"name": "phone",        "dtype": "string",  "aliases": ["Phone", "phone_number"]},
    {"name": "account_name", "dtype": "string",  "aliases": ["Company", "Account"]},
    {"name": "annual_rev",   "dtype": "integer", "aliases": ["Annual Revenue", "revenue"]},
    {"name": "lead_source",  "dtype": "category","aliases": ["Lead Source", "source"]},
    {"name": "created_date", "dtype": "date",    "aliases": ["Created", "create_date"]},
    {"name": "owner",        "dtype": "string",  "default": "unassigned"}
  ]
}