Camelot Key

{
  "asOf": "2026-10-12T01:46:27.551Z",
  "camelotCode": "8A",
  "camelotLetter": "A",
  "camelotNumber": 8,
  "compatible": true,
  "compatibleKeys": [
    {
      "code": "8A",
      "key": "A minor",
      "relation": "same key"
    },
    {
      "code": "9A",
      "key": "E minor",
      "relation": "one step up the wheel (a fifth above)"
    }
  ],
  "degraded": false,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "mixWithCode": "8B",
  "mixWithKey": "C major",
  "notChecked": [
    "tempo difference and energy, which matter as much as key when mixing",
    "tracks whose detected key is wrong or that change key partway",
    "…1 more"
  ],
  "reasons": [
    "Adjacent numbers on the same letter are a fifth apart; the same number on the other letter is the relative key.",
    "Number 1 follows 12, so the wheel wraps.",
    "…1 more"
  ],
  "source": "computed locally (Camelot numbering: 8B = C major, 8A = A minor; one step round the wheel = one fifth)",
  "standardKeyName": "A minor",
  "summary": "A minor is 8A on the Camelot wheel; it mixes with 9A, 7A, 8B. C major is 8B: compatible (1 step).",
  "verdict": "COMPATIBLE",
  "wheelSteps": 1
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://music-production-calc.x402tookit.com/camelot-key?key=Am&mixWith=C'

# 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/camelot-key?key=Am&mixWith=C' \
  | 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%2Fcamelot-key
const res = await pay("https://music-production-calc.x402tookit.com/camelot-key?key=Am&mixWith=C");
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/camelot-key?key=Am&mixWith=C")
    print(res.status_code, res.text)