Deck Calc

{
  "areaSqFt": 192,
  "asOf": "2026-10-11T14:25:12.645Z",
  "boardLinearFt": 416,
  "boardRows": 26,
  "boardsPerRow": 1,
  "boardsWithWaste": 29,
  "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.",
  "joistLengthFt": 12,
  "joists": 13,
  "notChecked": [
    "structural design: joist size and span, beams, posts, footings and ledger connections need a span table or engineer and local permits",
    "stairs, railings, picture-frame borders and diagonal layouts",
    "…2 more"
  ],
  "reasons": [
    "Board rows = width / (board width + gap), rounded up; boards run along the length and across the joists.",
    "1 board per row at 16 ft stock.",
    "…1 more"
  ],
  "screwsApprox": 710,
  "source": "computed locally",
  "stockLengthFt": 16,
  "summary": "192 sq ft deck: 26 board rows, 29 boards of 16 ft (10% waste), 13 joists 12 ft long at 16 in centres, about 710 screws.",
  "verdict": "ESTIMATE"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://construction-calc.x402tookit.com/deck-calc?boardWidthIn=5.5&gapIn=0.125&joistSpacingIn=16&lengthFt=16&stockLengthFt=16&widthFt=12'

# 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://construction-calc.x402tookit.com/deck-calc?boardWidthIn=5.5&gapIn=0.125&joistSpacingIn=16&lengthFt=16&stockLengthFt=16&widthFt=12' \
  | 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%2Fconstruction-calc.x402tookit.com%2Fdeck-calc
const res = await pay("https://construction-calc.x402tookit.com/deck-calc?boardWidthIn=5.5&gapIn=0.125&joistSpacingIn=16&lengthFt=16&stockLengthFt=16&widthFt=12");
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://construction-calc.x402tookit.com/deck-calc?boardWidthIn=5.5&gapIn=0.125&joistSpacingIn=16&lengthFt=16&stockLengthFt=16&widthFt=12")
    print(res.status_code, res.text)