Diamond Weight

{
  "asOf": "2026-10-12T01:40:58.737Z",
  "degraded": false,
  "depthMm": 3.965,
  "depthPercent": 61,
  "disclaimer": "Screening signal computed from the named public source. Not financial, legal or investment advice; provided as is. Verify at the source before acting.",
  "estimatedCarats": 1.022,
  "estimatedGrams": 0.204,
  "estimatedPoints": 102,
  "factor": 0.0061,
  "lengthMm": 6.5,
  "notChecked": [
    "the actual cut, girdle thickness and proportions, which move the weight by 10% or more",
    "gem density: factors assume diamond (other gems of the same size weigh differently)",
    "…1 more"
  ],
  "reasons": [
    "carat = 6.5 x 6.5 x 3.97 x 0.0061 (round factor).",
    "Treat this as an estimate within about 10%."
  ],
  "shape": "round",
  "source": "computed locally (carat = length x width x depth x shape factor; factors are common published approximations)",
  "summary": "6.5 mm round at 61% depth is about 1.02 ct.",
  "verdict": "COMPUTED",
  "widthMm": 6.5
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://jewelry-calc.x402tookit.com/diamond-weight?lengthMm=6.5&shape=round'

# 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://jewelry-calc.x402tookit.com/diamond-weight?lengthMm=6.5&shape=round' \
  | 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%2Fjewelry-calc.x402tookit.com%2Fdiamond-weight
const res = await pay("https://jewelry-calc.x402tookit.com/diamond-weight?lengthMm=6.5&shape=round");
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://jewelry-calc.x402tookit.com/diamond-weight?lengthMm=6.5&shape=round")
    print(res.status_code, res.text)