$ curl http://localhost:8899 -s -X POST -H "Content-Type: application/json" -d '
{"jsonrpc": "2.0", "id": 1, "method": "getTokenAccountBalance", "params": ["2uuvxpnEKw52aTqNerHiQ3WeSqZriCMNVt8LhWfrkbPk"]}' | jq .

{
  "jsonrpc": "2.0",
  "result": {
    "context": {
      "apiVersion": "2.2.14",
      "slot": 381130751
    },
    "value": {
      "amount": "10000000",
      "decimals": 6,
      "uiAmount": 20.0,
      "uiAmountString": "20"
    }
  },
  "id": 1
}

$ curl http://localhost:8899 -s -X POST -H "Content-Type: application/json" -d '
{"jsonrpc": "2.0", "id": 1, "method": "getAccountInfo", "params": ["2uuvxpnEKw52aTqNerHiQ3WeSqZriCMNVt8LhWfrkbPk", {"encoding": "jsonParsed"}]}' | jq .

{
  "jsonrpc": "2.0",
  "result": {
    "context": {
      "apiVersion": "2.2.14",
      "slot": 381131001
    },
    "value": {
      "data": {
        "parsed": {
          "info": {
            "extensions": [
              {
                "extension": "immutableOwner"
              },
              {
                "extension": "pausableAccount"
              }
            ],
            "isNative": false,
            "mint": "BZCd6HfTbb5ZYJ8hQsm8282tG4QzLyeqFR6tdgQA9EAG",
            "owner": "G7ARQSUCwNrfvTDUCZvM5xdiRdBJiN3qVw2PryD8Wnib",
            "state": "initialized",
            "tokenAmount": {
              "amount": "10000000",
              "decimals": 6,
              "uiAmount": 20.0,
              "uiAmountString": "20"
            }
          },
          "type": "account"
        },
        "program": "spl-token-2022",
        "space": 174
      },
      "executable": false,
      "lamports": 2101920,
      "owner": "TokenzQdBNbLqP5VEhdkAS6EPFLC1PHnBqCXEpPxuEb",
      "rentEpoch": 18446744073709551615,
      "space": 174
    }
  },
  "id": 1
}

import { address, createSolanaRpc } from "@solana/kit";

const rpc_url = "https://api.devnet.solana.com";
const rpc = createSolanaRpc(rpc_url);

const publicKey = address("BZCd6HfTbb5ZYJ8hQsm8282tG4QzLyeqFR6tdgQA9EAG");
const accountInfo = await rpc
  .getAccountInfo(publicKey, { encoding: "jsonParsed" })
  .send();

const mintData = accountInfo.value?.data as Readonly<{
  parsed: {
    info?: {
      extensions: {
        extension: string;
        state: object;
      }[];
    };
    type: string;
  };
  program: string;
  space: bigint;
}>;

const scaledUiAmountConfig = mintData.parsed.info?.extensions?.find(
  (extension) => extension.extension === "scaledUiAmountConfig"
) as Readonly<{
  state: {
    newMultiplierEffectiveTimestamp: number;
    newMultiplier: number;
    multiplier: number;
  };
}>;

const currentMultiplier =
  scaledUiAmountConfig?.state &&
  Date.now() / 1000 >=
    scaledUiAmountConfig.state.newMultiplierEffectiveTimestamp
    ? scaledUiAmountConfig.state.newMultiplier
    : scaledUiAmountConfig.state.multiplier;

console.log("Scaled UI Amount Config:", scaledUiAmountConfig);
console.log("Current Multiplier:", currentMultiplier);
/*
Scaled UI Amount Config: {
  extension: 'scaledUiAmountConfig',
  state: {
    authority: 'G7ARQSUCwNrfvTDUCZvM5xdiRdBJiN3qVw2PryD8Wnib',
    multiplier: '2',
    newMultiplier: '2',
    newMultiplierEffectiveTimestamp: 1743000000n
  }
}
Current Multiplier: 2
*/