Query real-time stock prices and market data using the Stock Prices API. Responses are in TOON format—decode with @toon-format/toon. Use when fetching stock quotes, analyzing market data, or working with symbols like AAPL, NVDA, GOOGL, or any ticker symbols.
This skill helps you work with the Stock Prices API to fetch real-time market data and stock quotes.
Base URL: https://stock-prices.on99.app
Primary Endpoint: /quotes?symbols={SYMBOLS}
Fetch stock quotes for one or more symbols (responses are in TOON format):
curl "https://stock-prices.on99.app/quotes?symbols=NVDA"
curl "https://stock-prices.on99.app/quotes?symbols=AAPL,GOOGL,MSFT"
Install the TOON decoder for parsing: pnpm add @toon-format/toon
The API returns TOON (Token-Oriented Object Notation) format—a compact, human-readable encoding that uses ~40% fewer tokens than JSON. This makes it ideal for LLM prompts and streaming.
quotes[1]{symbol,currentPrice,change,percentChange,highPrice,lowPrice,openPrice,previousClosePrice,preMarketPrice,preMarketChange,preMarketTime,preMarketChangePercent,...}:
NVDA,188.54,-1.5,-0.789308,192.48,188.12,191.405,190.04,191.8799,3.3399048,2026-02-11T13:49:16.000Z,1.771457,...
Use @toon-format/toon to parse responses back to JavaScript/JSON:
import { decode } from "@toon-format/toon";
const response = await fetch("https://stock-prices.on99.app/quotes?symbols=NVDA");
const toonText = await response.text();
const data = decode(toonText);
// data.quotes is an array of quote objects
const quote = data.quotes[0];
console.log(`${quote.symbol}: $${quote.currentPrice}`);
The decoded structure matches JSON—same objects, arrays, and primitives.
| Field | Type | Description |
|---|---|---|
symbol | string | Stock ticker symbol |
currentPrice | number | Current trading price |
change | number | Price change from previous close |
percentChange | number | Percentage change from previous close |
highPrice | number | Day's high price |
lowPrice | number | Day's low price |
openPrice | number | Opening price |
previousClosePrice | number | Previous day's closing price |
preMarketPrice | number | Pre-market trading price |
preMarketChange | number | Pre-market price change |
preMarketTime | string (ISO 8601) | Pre-market data timestamp |
preMarketChangePercent | number | Pre-market percentage change |
Query multiple stocks by separating symbols with commas (max 50):
curl "https://stock-prices.on99.app/quotes?symbols=AAPL,GOOGL,MSFT,TSLA,AMZN"
Always check for valid responses. Decode TOON before accessing data:
import { decode } from "@toon-format/toon";
const response = await fetch("https://stock-prices.on99.app/quotes?symbols=NVDA");
const data = decode(await response.text());
if (data.quotes && data.quotes.length > 0) {
const quote = data.quotes[0];
console.log(`${quote.symbol}: $${quote.currentPrice}`);
}
Calculate common metrics:
// Determine if stock is up or down
const isUp = quote.change > 0;
const direction = isUp ? "📈" : "📉";
// Calculate day's range percentage
const rangePct = ((quote.highPrice - quote.lowPrice) / quote.lowPrice) * 100;
// Compare current to open
const vsOpen = quote.currentPrice - quote.openPrice;
import { decode } from "@toon-format/toon";
async function checkPrice(symbol: string) {
const res = await fetch(`https://stock-prices.on99.app/quotes?symbols=${symbol}`);
const data = decode(await res.text());
const quote = data.quotes[0];
return {
price: quote.currentPrice,
change: quote.change,
changePercent: quote.percentChange,
};
}
import { decode } from "@toon-format/toon";
async function getPortfolio(symbols: string[]) {
const symbolString = symbols.join(",");
const res = await fetch(`https://stock-prices.on99.app/quotes?symbols=${symbolString}`);
const data = decode(await res.text());
return data.quotes.map(q => ({
symbol: q.symbol,
value: q.currentPrice,
dailyChange: q.percentChange,
}));
}
import { decode } from "@toon-format/toon";
async function marketSummary(symbols: string[]) {
const res = await fetch(`https://stock-prices.on99.app/quotes?symbols=${symbols.join(",")}`);
const data = decode(await res.text());
const gainers = data.quotes.filter(q => q.change > 0);
const losers = data.quotes.filter(q => q.change < 0);
return {
totalStocks: data.quotes.length,
gainers: gainers.length,
losers: losers.length,
avgChange: data.quotes.reduce((sum, q) => sum + q.percentChange, 0) / data.quotes.length,
};
}
AAPL - AppleGOOGL - Alphabet (Google)META - Meta (Facebook)AMZN - AmazonNFLX - NetflixMSFT - MicrosoftNVDA - NVIDIATSLA - TeslaAMD - Advanced Micro DevicesINTC - IntelORCL - Oracle^GSPC - S&P 500^DJI - Dow Jones^IXIC - NASDAQdecode() from @toon-format/toon to parse.