Endpoint: /portfolio/balance
Method:
GET

Request Parameters:
user_id: (Required) The unique ID of the user.
Response:
A JSON object containing the balance of all cryptocurrencies in the user’s portfolio.

{
“status”: “success”,
“data”: {
“BTC”: “0.5”,
“ETH”: “10”
}
}

Errors:
400 Bad Request: If the user_id is missing or invalid.
500 Internal Server Error: If there’s an issue processing the request.