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GOLD: --
Karatology Metal Price API

The metal price API built for jewelers and developers

Live gold, silver, platinum and palladium prices, plus karat, fineness and melt-value endpoints that return the numbers a jewelry counter actually uses. Per gram, pennyweight or tola, with a timestamp on every response.

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Free plan: 10 calls a month to every endpoint. No card required. Paid plans from $15 a month.

GET /v1/karat?unit=g

Request
curl "https://api.karatology.com/v1/karat?unit=g" \
  -H "X-API-Key: kt_live_YOUR_KEY"
Example response
{
  "success": true,
  "timestamp": "2026-11-10T01:04:07.389Z",
  "age_seconds": 2040,
  "stale": false,
  "currency": "USD",
  "unit": "g",
  "metal": "gold",
  "spot_price_toz": 4130.4,
  "karats": [
    { "karat": "24K", "purity": 0.999, "fineness": 999, "price": 132.6623 },
    { "karat": "22K", "purity": 0.9167, "fineness": 916.7, "price": 121.7329 },
    { "karat": "18K", "purity": 0.75, "fineness": 750, "price": 99.5963 },
    { "karat": "14K", "purity": 0.5833, "fineness": 583.3, "price": 77.4594 },
    ...
  ]
}

Trimmed to 4 of 12 karats. Illustrative values, not current prices.

  • 4metals

    Gold, silver, platinum and palladium

  • 5units

    Troy ounce, gram, kilogram, pennyweight (dwt) and tola

  • 12karat grades

    From 24K down to 8K, priced per unit

  • Everyresponse timestamped

    With its age in seconds and a stale flag

Endpoints

Seven endpoints, one consistent response

Every price endpoint returns the same envelope: success, timestamp, age_seconds, stale, currency and unit, with the endpoint's own fields alongside. Most take a unit parameter: toz, g, kg, dwt or tola.

Why Karatology

Built by people who explain gold purity for a living

Karatology publishes guides on karats, hallmarks and melt value. The API returns those same numbers in a form your software can use.

  • Jeweler-ready numbers in every plan

    Karat, fineness and melt-value endpoints are part of every plan, including Free. They are not an add-on you have to upgrade for.

  • Transparent timestamps

    Every response says when its price was collected and how old it is. A stale flag turns true if a price is more than 2 hours old, so you never show an old number by accident.

  • Browser-ready CORS

    Call the API straight from front-end code. CORS headers and preflights are handled on every endpoint, including errors.

  • Failed calls never count

    Only successful price responses count toward your quota. Errors, usage checks, reference data and preflight requests are free.

  • Simple keys you can roll

    Create, name, roll and revoke keys from your dashboard. Keys are shown once and stored only as a secure hash.

  • Docs connected to real gold education

    Not sure what 585 or 750 means, or why 22K is 0.9167 pure? Our gold karat chart and hallmark guides explain the numbers behind every endpoint.

Use cases

From the jewelry counter to the codebase

The same prices serve a shop owner who wants a price board and a developer building a pricing engine.

  • Jewelry store price boards

    Show today's gold price per gram for 24K, 22K, 18K and 14K on a counter screen or your website, with the time each price was collected.

    Endpoints used:/karat/latest

  • Scrap and pawn buyers

    Enter the weight and karat of a piece and get its melt value, plus your payout at the percent of melt you pay, in a single call.

    Endpoints used:/melt

  • Shopify, WooCommerce and custom sites

    Pull live metal prices into a storefront theme, a product page widget or a backend job that updates prices for items sold by metal weight.

    Endpoints used:/latest/karat

  • Apps and calculators

    Power gold calculators, scrap estimators and portfolio trackers with prices in grams, pennyweights, tolas or troy ounces.

    Endpoints used:/spot/melt/fineness

  • Newsletters and dashboards

    Build daily price snapshots with the change from the previous close, plus the gold to silver ratio your readers watch.

    Endpoints used:/latest/ratios

  • Building something else? The API reference covers every parameter, error code and response header.

How it works

Live prices in three steps

  1. Step 1: Create a free account

    Sign up with your email. The Free plan includes 10 calls a month to every endpoint, and no card is required.

  2. Step 2: Generate an API key

    Create a key in your dashboard and give it a name. It is shown once, so store it somewhere safe, such as an environment variable.

  3. Step 3: Call the API

    Send the key in the X-API-Key header and get JSON back with a timestamp, plus your remaining quota in the response headers.

Create a free accountRead the quick start
Pricing

Start free, upgrade when you need volume

Plans differ by calls a month, speed, keys and support. Every plan, including Free, gets every endpoint.

  • Free

    $0/month

    10 calls a month

    Try every endpoint before you buy.

  • Starter

    $15/month

    500 calls a month

    For a single shop showing live prices.

  • Basic

    $29/month

    5,000 calls a month

    For busy storefronts and price boards.

  • Recommended

    Pro

    $59/month

    25,000 calls a month

    For apps, buyers and multi-store jewelers.

  • Business

    $149/month

    100,000 calls a month

    For platforms serving many merchants.

Every plan includes every endpoint. Yearly billing gets 2 months free. Need more than 100,000 calls a month? Enterprise plans offer custom volume and invoice billing.

Compare all plans
Questions

Frequently asked questions

Every call fetches current prices at request time; Karatology does not serve prices from a stored copy. New prices are collected hourly, and every response includes a timestamp showing when its price was collected, an age_seconds value, and a stale flag that turns true if a price is more than 2 hours old.
Gold, silver, platinum and palladium (the symbols XAU, XAG, XPT and XPD also work). Prices are available per troy ounce, gram, kilogram, pennyweight (dwt) and tola. All prices are in US dollars.
Yes. Every plan, including Free, gets every endpoint: latest, spot, karat, fineness, melt, ratios and usage. Paid plans add monthly volume, a higher per-minute limit, more keys and support, not extra features.
Only successful responses from price endpoints count toward your monthly quota. Errors, usage checks, reference data and browser preflight requests are never counted. A /latest call returns all four metals and counts as one call.
The Free plan stops at 10 calls a month. Paid plans include a 10% grace above the included calls, then calls pause with a quota_exceeded response until the quota resets at 00:00 UTC on the 1st of the month or you upgrade. There are no overage bills.
Yes. CORS is enabled on every endpoint, so front-end code can call the API directly. A key used in browser code is visible to visitors, so we recommend calling from your server, or using a dedicated key you can roll from the dashboard.
No. Melt value is the pure metal content of a piece multiplied by the current spot price. It does not include labor, design, stones, refining costs or a dealer margin, and it is not an appraisal, an offer to buy, or a guaranteed value. All prices are indicative; see the API terms for details.
Yes. Cancel from the billing page in your dashboard and your plan stays active until the end of the period you paid for. After that, your account moves to the Free plan.

Something else? Read the API terms or see plan details.

Get started

Put live karat prices to work today

Create a free account, generate a key and make your first call in minutes. Upgrade only when you need more volume.

Start freeView pricing