Trading apps live or die by fast, reliable price data. Charts, alerts, watchlists and order tickets all need accurate, sub-second updates.
Building a trading app is mostly a data engineering problem disguised as a UI project. Your charts, watchlists, alerts, screeners, and order tickets all depend on one thing: fast, accurate, and continuously updating prices.
Choosing and integrating a real-time market data API is one of the most critical early decisions you will make. This guide provides a practical, step-by-step approach using Real Market API β a developer-friendly service offering real-time data via REST, WebSocket, built-in technical indicators, and AI-native MCP access.
Youβll learn how to define requirements, connect to live streams, normalize symbols, handle reconnects gracefully, manage rate limits, cache efficiently, and ship a reliable production-grade integration.
βReal-timeβ means different things depending on the asset class and user expectations. For most trading applications, it includes:
The goal: a user opens a watchlist and immediately sees accurate prices, then watches smooth continuous updates without freezing, drifting values, or silent disconnections.
Real Market API provides three main access channels:
| Channel | Base URL | Best For |
|---|---|---|
| β‘ REST API | https://api.realmarketapi.com | Snapshots, historical data, indicators, queries |
| π WebSocket | wss://api.realmarketapi.com | Continuous live price & candle streams |
| π€ MCP Server | https://ai.realmarketapi.com/mcp | AI agents (Claude, Cursor, custom tools) |
Start with use cases, not endpoints. List the screens and features planned for your first release β they determine exactly what data you need.
Instruments & coverage Real Market API supports 23+ symbols across 6 asset classes:
| Asset Class | Symbols |
|---|---|
| π₯ Metals | XAUUSD, XAGUSD |
| π± Forex | EURUSD, GBPUSD, USDJPY, GBPJPY, USDVND, AUDUSD |
| βΏ Crypto | BTCUSD, ETHUSD, XRPUSD |
| π’οΈ Commodities | USOIL, UKOIL, XNGUSD |
| π Indices | US500, US30 |
| π Stocks | AAPL, TSLA, NFLX, MSFT, AMZN, AMD, NVDA |
Timeframes β M1, M5, M15, H1, H4, D1
Data types β OHLCV candles, Bid/Ask quotes, volume, technical indicators
Latency β sub-150 ms average REST, sub-second WebSocket
Document these requirements first β it prevents costly rework later in caching, symbol mapping, and backfill logic.
Many teams begin by connecting WebSocket directly from the browser β great for prototypes, bad for production.
| Pattern | Pros | Cons |
|---|---|---|
| Client β Provider | Fastest to prototype | Exposes API keys, no caching, hard to scale |
| Server β Provider β Client | Secure keys, caching, deduplication, alerts | Requires backend infrastructure |
| Edge Gateway | Lowest possible latency for global users | More complex deployment |
π‘ Server-side aggregator is usually the best choice if your app includes watchlists, alerts, or notifications. Real Market API also lets you offload indicator calculations entirely to the server.
Authentication is simple: append apiKey as a query parameter (same across REST, WebSocket, and MCP).
Examples:
text
REST: https://api.realmarketapi.com/api/v1/price?apiKey=YOUR_KEY&symbolCode=XAUUSD&timeFrame=M1
WebSocket: wss://api.realmarketapi.com/price?apiKey=YOUR_KEY&symbolCode=XAUUSD&timeFrame=M1
Never rely only on streaming updates for initial render β users hate blank screens.
Recommended flow:
JavaScript
// 1. Get snapshot
const res = await fetch(
`https://api.realmarketapi.com/api/v1/price?apiKey=${API_KEY}&symbolCode=XAUUSD&timeFrame=M1`
);
const snapshot = await res.json();
// Render UI with snapshot...
// 2. Then connect to live stream
const ws = new WebSocket(
`wss://api.realmarketapi.com/price?apiKey=${API_KEY}&symbolCode=XAUUSD&timeFrame=M1`
);
ws.onmessage = (event) => {
const update = JSON.parse(event.data);
// Update UI (same data shape as REST)
};
This pattern makes the app feel instant, even on slow networks.
WebSocket delivers continuous OHLCV + bid/ask updates (available on Pro plan and above).
Connection example:
text
wss://api.realmarketapi.com/price?apiKey=YOUR_KEY&symbolCode=XAUUSD&timeFrame=M1
Each message contains a complete candle object.
Networks are unreliable β especially on mobile. Assume disconnection is normal.
Key practices:
JavaScript
// Simplified reconnect example
let reconnectAttempts = 0;
const maxDelay = 30000;
function connect() {
const ws = new WebSocket(url);
ws.onclose = () => {
const delay = Math.min(1000 * Math.pow(2, reconnectAttempts) + Math.random() * 1000, maxDelay);
setTimeout(connect, delay);
reconnectAttempts++;
};
ws.onopen = () => {
reconnectAttempts = 0;
// Fetch snapshot to backfill any gap
};
}
Use clean internal symbol format (e.g. XAUUSD, AAPL).
Fetch the full supported symbol list:
text
GET https://api.realmarketapi.com/api/v1/symbols?apiKey=YOUR_KEY
Standardize your internal quote/candle model so every part of the app (charts, alerts, watchlists) uses the same structure.
Caching reduces costs, improves speed, and helps survive short outages.
| Layer | What to cache | Typical TTL |
|---|---|---|
| In-memory | Latest quote per symbol | Until next tick |
| Redis / shared | Latest quotes, recent candles, indicators | 5β60 seconds |
| Time-series DB | Historical candles for charts & backtesting | Permanent |
Flow for stable charts:
No need to calculate indicators locally (Pro+ plans):
Central server:
Combine with indicator endpoints for complex conditions.
Plan comparison (simplified):
| Feature | Free | Starter | Pro | Business | Enterprise |
|---|---|---|---|---|---|
| REST API | β | β | β | β | β |
| WebSocket | β | β | β | β | β |
| Indicators | β | β | β |
Optimization techniques:
Must-have tests:
Pro+ plans include MCP server β natural language access for AI agents (Claude, Cursor, custom).
Example tools: get_price, get_rsi, get_support_resistance, get_history.
Follow this flow and youβll have a robust, production-ready real-time market data integration.
Ready to get started? Create a free account β (no credit card required)
Full documentation: https://realmarketapi.com/docs
Historical depth β 30 days (Starter) β 1 year (Pro) β 10 years (Business)
Scale β concurrent users, symbols per user, peak load during market open
Compliance β data retention, storage location, redistribution rules
| β |
| β |
| Historical depth | β | 30 days | 1 year | 10 years | Custom |
| Monthly requests | 5k | 10k | 100k | 500k | Unlimited |