Tempo

{
  "asOf": "2026-10-11T14:26:15.047Z",
  "barMs": 2000,
  "beatsPerBar": 4,
  "bpm": 120,
  "degraded": false,
  "delayTimes": {
    "dottedEighth": 375,
    "eighth": 250,
    "eighthTriplet": 166.67,
    "note": "delay times in ms for the common divisions",
    "quarter": 500,
    "sixteenth": 125
  },
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "notChecked": [
    "swing, groove or human timing",
    "whether the taps were meant as quarter notes (a half-time or double-time feel gives half or double the BPM)",
    "…1 more"
  ],
  "noteValues": [
    {
      "beats": 4,
      "dottedMs": 3000,
      "note": "whole",
      "straightHz": 0.5,
      "straightMs": 2000,
      "tripletMs": 1333.33
    },
    {
      "beats": 2,
      "dottedMs": 1500,
      "note": "half",
      "straightHz": 1,
      "straightMs": 1000,
      "tripletMs": 666.67
    }
  ],
  "quarterNoteMs": 500,
  "reasons": [
    "Quarter note = 60000 / BPM milliseconds; dotted = x1.5, triplet = x2/3 of the straight value."
  ],
  "source": "computed locally",
  "summary": "120 BPM: quarter 500 ms, eighth 250 ms, dotted eighth 375 ms, sixteenth 125 ms; bar of 4 = 2000 ms.",
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://music-theory.x402tookit.com/tempo?bpm=120'

# x402 v2 sends the challenge base64-encoded in the PAYMENT-REQUIRED header (v1 sends it in the body).
# To read the header:
curl -sS -g -o /dev/null -D - 'https://music-theory.x402tookit.com/tempo?bpm=120' \
  | grep -i '^payment-required:' | cut -d' ' -f2 | tr -d '\r' | base64 --decode

// npm i @x402/fetch @x402/evm viem
import { wrapFetchWithPayment, x402Client } from "@x402/fetch";
import { registerExactEvmScheme } from "@x402/evm/exact/client";
import { privateKeyToAccount } from "viem/accounts";

// Pays at most $0.02 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.02" });
registerExactEvmScheme(client, { signer: privateKeyToAccount(process.env.EVM_PRIVATE_KEY) });
const pay = wrapFetchWithPayment(fetch, client);

// Not sure it's safe to pay? ToolVet checks it first for $0.005. Pay for that from a separate
// client: this one is capped at $0.02 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Fmusic-theory.x402tookit.com%2Ftempo
const res = await pay("https://music-theory.x402tookit.com/tempo?bpm=120");
console.log(res.status, await res.text());

# pip install "x402[requests,evm]"
import os
from eth_account import Account
from x402 import x402ClientSync
from x402.http.clients import x402_requests
from x402.mechanisms.evm import EthAccountSigner
from x402.mechanisms.evm.exact.register import register_exact_evm_client

# Pays at most $0.02 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.02"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://music-theory.x402tookit.com/tempo?bpm=120")
    print(res.status_code, res.text)