Convex

{
  "type": "object",
  "required": ["address"],
  "properties": {
                  "address": {
                               "type": "string",
                               "description": "Account address to check (e.g. '#13')"
                             },
                  "token": {
                             "type": "string",
                             "description": "Token actor address for fungible token balance (e.g. '#128'). Omit or nil for native CVM coin."
                           }
                }
}

{
  "type": "object",
  "properties": {
                  "address": {
                               "type": "number",
                               "description": "Account address queried"
                             },
                  "balance": {
                               "description": "Balance amount (copper for CVM, token units for fungible tokens)"
                             },
                  "token": {
                             "description": "Token address if a fungible token was queried, null for CVM"
                           }
                }
}