Food Compare

{
  "a": {
    "barcode": "3017620422003",
    "brands": "Nutella, Ferrero",
    "dataQuality": {
      "completeness": 89,
      "hasIngredients": true,
      "lastModified": "2026-10-10"
    },
    "name": "Nutella",
    "novaGroup": 4,
    "nutriScore": "E",
    "quantity": "400 g e"
  },
  "asOf": "2026-10-11T05:19:24.404Z",
  "attribution": "Data: Open Food Facts contributors (ODbL).",
  "b": {
    "barcode": "5449000000996",
    "brands": "COCA-COLA SERVICES SA/NV",
    "dataQuality": {
      "completeness": 89,
      "hasIngredients": true,
      "lastModified": "2026-10-10"
    },
    "name": "Coca-Cola Original",
    "novaGroup": 4,
    "nutriScore": "E",
    "quantity": "330 ml"
  },
  "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.",
  "notChecked": [
    "serving sizes (comparison is per 100 g, not per portion)",
    "ingredients quality beyond the numbers",
    "…1 more"
  ],
  "per100g": [
    {
      "a": 539,
      "b": 42.4,
      "difference": 496.6,
      "nutrient": "energy (kcal)"
    },
    {
      "a": 56.3,
      "b": 10.6,
      "difference": 45.7,
      "nutrient": "sugars (g)"
    }
  ],
  "reasons": [
    "Nutri-Score A is best, E worst; it rates the nutrient profile only, not the whole diet.",
    "Missing numbers are unknown, not zero.",
    "…1 more"
  ],
  "source": "Open Food Facts",
  "sourceUrl": "https://world.openfoodfacts.org",
  "summary": "Nutella (Nutri-Score E) vs Coca-Cola Original (E). Per 100 g sugars 56.3 vs 10.6 g, salt 0.107 vs 0 g.",
  "verdict": "SAME_NUTRISCORE"
}

# bash or zsh: see the payment challenge. Nothing is charged.
curl -sS -g -i 'https://food-barcode.x402tookit.com/food-compare?barcode=3017620422003&other=5449000000996'

# 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://food-barcode.x402tookit.com/food-compare?barcode=3017620422003&other=5449000000996' \
  | 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 $0.05 per call.
const client = new x402Client().setSpendControls({ maxAmountPerPayment: "$0.05" });
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 $0.05 per payment. GET https://toolvet.app/api/v1/check?url=https%3A%2F%2Ffood-barcode.x402tookit.com%2Ffood-compare
const res = await pay("https://food-barcode.x402tookit.com/food-compare?barcode=3017620422003&other=5449000000996");
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 $0.05 per call.
client = x402ClientSync().set_spend_controls({"max_amount_per_payment": "$0.05"})
register_exact_evm_client(client, EthAccountSigner(Account.from_key(os.environ["EVM_PRIVATE_KEY"])))

with x402_requests(client) as session:
    res = session.get("https://food-barcode.x402tookit.com/food-compare?barcode=3017620422003&other=5449000000996")
    print(res.status_code, res.text)