Calculate minimal rent exemption balance for a Solana account

calc_rent_exemption.py

"""
A simple cmd line script to calculate the minimal rent exemption balance
of a Solana account.

Usage:

    python calc_rent_exemption.py ACCONUT_ADDRESS

"""


import base64
import sys
import requests


RPC_URL = "https://api.mainnet-beta.solana.com"


def calc_rent_exemption(address: str) -> int:
    get_account_info = {
        "jsonrpc": "2.0",
        "id": 1,
        "method": "getAccountInfo",
        "params": [address, {"encoding": "base64"}]
    }
    resp = requests.post(RPC_URL, json=get_account_info)

    account_info = resp.json()
    data = account_info["result"]["value"]["data"][0]
    data_size = len(base64.b64decode(data))

    get_rent_exempt_balance = {
        "jsonrpc": "2.0",
        "id": 2,
        "method": "getMinimumBalanceForRentExemption",
        "params": [data_size]
    }
    resp = requests.post(RPC_URL, json=get_rent_exempt_balance)
    return resp.json()["result"]


if __name__ == "__main__":
    address = sys.argv[1]
    rent_exemption = calc_rent_exemption(address)
    print(f"{(rent_exemption * 1e-9):.9} SOL")