Three-letter ISO 4217 currency code
{ "$schema": "http://json-schema.org/draft-07/schema#", "$id": "https://raw.githubusercontent.com/api-evangelist/fastforex/main/json-schema/currency.json", "title": "Currency", "description": "Three-letter ISO 4217 currency code", "type": "string", "pattern": "[A-Z]{3}" }