Delay Tail

{
  "asOf": "2026-10-12T01:46:27.817Z",
  "dbPerRepeat": -6.0206,
  "decayTargetDb": 60,
  "degraded": false,
  "delayMs": 500,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "feedbackPercent": 50,
  "feedbackRatio": 0.5,
  "firstRepeatLevels": [
    {
      "levelDb": -6.02,
      "repeat": 1,
      "timeMs": 500
    },
    {
      "levelDb": -12.04,
      "repeat": 2,
      "timeMs": 1000
    }
  ],
  "notChecked": [
    "filters, saturation or ducking in the feedback path, which change the decay",
    "the very first (dry plus first repeat) level, which depends on the wet/dry mix",
    "…1 more"
  ],
  "reasons": [
    "Each repeat is feedback x the previous one, so after n repeats the level is f^n, or n x 20 x log10(f) dB.",
    "Repeats are rounded up to the first one at or below the target."
  ],
  "repeatsToTarget": 10,
  "source": "computed locally (each repeat is scaled by f: dB per repeat = 20 x log10 f; repeats = decay dB / dB per repeat, rounded up)",
  "summary": "50% feedback loses 6.021 dB per repeat: 10 repeats (5000 ms) to fall 60 dB.",
  "tailMs": 5000,
  "tailSeconds": 5,
  "verdict": "COMPUTED"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://music-production-calc.x402tookit.com/delay-tail?delayMs=500&feedbackPercent=50'

# 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-production-calc.x402tookit.com/delay-tail?delayMs=500&feedbackPercent=50' \
  | 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-production-calc.x402tookit.com%2Fdelay-tail
const res = await pay("https://music-production-calc.x402tookit.com/delay-tail?delayMs=500&feedbackPercent=50");
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-production-calc.x402tookit.com/delay-tail?delayMs=500&feedbackPercent=50")
    print(res.status_code, res.text)