Algorand TPS (defaults to 100 rounds)

index.js

import algosdk from 'algosdk';

const BLOCKRANGE = 100;
const blocks = [];

const algod = new algosdk.Algodv2(
	'',
	'https://mainnet-api.algonode.cloud',
	443
);

// Recursively count transactions. Including transactions created by smart contracts.
function countTransactions(txns) {
	let n = 0;

	for (const txn of txns) {
		if ('dt' in txn && 'itx' in txn['dt']) {
			n += countTransactions(txn['dt']['itx']);
		}
		n++;
	}

	return n;
}

const start = await algod.status().do();
let lastRound = start['last-round'];

console.log("Algorand TPS");
console.log("Waiting for next block...");

while (true) {
	const status = await algod.statusAfterBlock(lastRound).do();
	lastRound = status['last-round'];

	const block = await algod.block(lastRound).do();
	blocks.push({
		timestamp: block['block']['ts'],
		round: block['block']['rnd'],
		transactions: countTransactions(block['block']['txns'])
	});
	if (blocks.length > BLOCKRANGE) blocks.shift();

	const newBlock = blocks.length - 1;
	const duration = blocks[newBlock]['timestamp'] - blocks[0]['timestamp'];
	const totalTxns = blocks.reduce((sum, blk) => { return sum + blk['transactions']; }, 0);
	const tps = duration ? totalTxns / duration : totalTxns;

	console.log(`[${new Date(blocks[newBlock]['timestamp'] * 1000).toLocaleString()}] Round: ${blocks[newBlock]['round']} Txns: ${blocks[newBlock]['transactions'].toString().padEnd(5)} (${tps.toFixed(2)} tx/s)`);
}

I'd recommend instead of recursively looping through counting transactions you could instead use the 'tc' property of the block. This is the raw transaction counter. ie: Block 100, tc: 5,000,000. Block 101, tc: 5,001,235. From that alone you know that 235 transactions occurred in that block. Track across blocks and can get averages.

Comment from the block header code:
// TxnCounter is the number of the next transaction that will be
// committed after this block. Genesis blocks can start at either
// 0 or 1000, depending on a consensus parameter (AppForbidLowResources).
TxnCounter uint64 codec:"tc"