Real-Time Data API via Websockets: US Stocks, Forex pairs, Digital Currencies

Product Landing Page Coding Libraries (Python, etc) Explore Plans Including the API Sign up & Get the API

Available in plans: All-In-One and EOD+Intraday — All World Extended plans. Explore plans

API calls consumption: Does not consume API calls.

How does API call system work?

EODHD offers one of the best ways for investors, developers, and data analysts to incorporate real-time finance data for the US market, 1100+ Forex pairs, 1000+ Digital Currencies into their decision-making projects with a delay of less than 50ms via WebSockets. For US stocks our real-time data API supports pre-market and post-market hours (from 4 am to 8 pm EST).

The subscription provides real-time access to prices for 50 tickers simultaneously via WebSockets. Additionally, the 50-symbol limit can be increased through the user dashboard.

For global markets and all exchanges around the world we also offer Live (Delayed) data with 15min delay.

Sign up & Get Data

What is WebSocket protocol

WebSockets is a communication protocol that provides full-duplex communication channels over a single TCP connection. It enables real-time communication between a client and a server, allowing them to exchange messages continuously without the overhead of repeatedly establishing new connections. In the case of financial data providers, Websockets API provides real-time stock market information with minimal delay.

Providing clients with the WebSocket protocol for real-time data answers the question: ‘What is the best stock market data API?”. Since websocket technology is quite resource consuming, “free stock API for real-time market data” stays as feature impossible to find. EODHD provides real-time data in paid plans EOD+Intraday and ALL-IN-ONE. Read more about plans here.

What you get (Data availability)

US Stocks (full list of US tickers available)
• Trade stream (last price, size, conditions, etc.)
• Quote stream (bid/ask, sizes)
• Covers primary US exchanges (e.g., NASDAQ, NYSE)
• Extended hours supported (pre‑ and post‑market)

FOREX (full list of available currency pairs)
• Bid/ask + day change/difference
• Tickers like EURUSD, AUDUSD, etc.

Digital Currencies (Full list of available crypto pairs)
• Last price, quantity, day change/difference
• Tickers like ETH-USD, BTC-USD

Lists of available tickers and pairs for Real-Time feeds can be retrieved in JSON format via this API endpoint, providing the full list of exchange or asset class components (use “US” for US stocks, “CC” for cryptocurrencies, “FOREX” for currency pairs).

Demo access is available with API key “demo” for: AAPL, MSFT, TSLA, EURUSD, ETH-USD, BTC-USD.

Updates & Latency

  • Streaming updates pushed in real time over a persistent WebSocket connection.
  • Typical transport latency < 50 ms from our gateway to your client (excluding network distance).
  • Market status flag indicates open, closed, or extended hours for US stocks.

Endpoints

Open connection – use wss:// in production. ws:// is available for local testing.

US Equities (Trades and Quotes):

wss://ws.eodhistoricaldata.com/ws/us?api_token=YOUR_API_KEY
wss://ws.eodhistoricaldata.com/ws/us-quote?api_token=YOUR_API_KEY


Forex

wss://ws.eodhistoricaldata.com/ws/forex?api_token=YOUR_API_KEY

Crypto

wss://ws.eodhistoricaldata.com/ws/crypto?api_token=YOUR_API_KEY

Subscribe / Unsubscribe

After the socket is open, send JSON commands.

Subscribe:

{"action": "subscribe", "symbols": "ETH-USD"}

Multiple symbols (comma‑separated):

{"action": "subscribe", "symbols": "AAPL,TSLA"}

Unsubscribe:

{"action": "unsubscribe", "symbols": "ETH-USD,BTC-USD"}

Response Schemas

US Trades (endpoint: /ws/us):

{
"s": "AAPL",        // ticker
"p": 227.31,        // last trade price
"v": 100,           // trade size (shares)
"c": 12,            // trade condition code (see glossary)
"dp": false,        // dark pool (true/false)
"ms": "open",       // market status: open | closed | extended hours
"t": 1725198451165  // epoch ms
}

Note: US trade messages include “c” (numeric) that maps to a condition code. See the downloadable glossary in the docs (pdf).

US Quotes (endpoint: /ws/us-quote):

{
"s": "AAPL",         // ticker
"ap": 227.33,        // ask price
"as": 200,           // ask size
"bp": 227.30,        // bid price
"bs": 100,           // bid size
"t": 1725198451165   // epoch ms
}

FOREX (endpoint: /ws/forex):

{
"s": "EURUSD",       // symbol
"a": 1.08675,        // ask
"b": 1.08665,        // bid
"dc": 0.21,          // daily change, %
"dd": 0.0023,        // daily difference, price units
"ppms": false,       // pre/post market status (always false for FX)
"t": 1725198451165.  // epoch ms
}

Crypto (endpoint: /ws/crypto):

{
"s": "ETH-USD",       // symbol
"p": 2874.12,         // last price
"q": 0.145,           // trade quantity
"dc": -0.54,          // daily change, %
"dd": -15.61,         // daily difference, price units
"t": 1725198451165.   // epoch ms
}

Symbol Limits & Usage Notes

Concurrent subscriptions: up to 50 symbols per connection by default (upgradeable in user dashboard for extra fee).

Tickers:

  • US: use plain tickers like AAPL, MSFT
  • Forex: no separator, e.g., EURUSD
  • Crypto: dash‑separated, e.g., BTC-USD

Resubscribe on reconnect: if the socket reconnects, re‑send your current subscriptions.
Compression/Throughput: consider batching symbol lists in a single subscribe call for efficiency.

Examples (copy‑paste ready)

Open connection for US trades:

wss://ws.eodhistoricaldata.com/ws/us?api_token=demo

Then send:

{"action": "subscribe", "symbols": "AMZN,TSLA"}


Open connection for Forex pairs:

wss://ws.eodhistoricaldata.com/ws/forex?api_token=demo

Then send:

{"action": "subscribe", "symbols": "EURUSD,AUDUSD"}


Open connection for Crypto:

wss://ws.eodhistoricaldata.com/ws/crypto?api_token=demo

Then send:

{"action": "subscribe", "symbols": "ETH-USD,BTC-USD"}

Tools for Testing

Chrome: Simple WebSocket Client extension (open a socket, paste open URL, send JSON quote).

EODHD Chrome extension: free mini ticker window for live Stocks/FX/Crypto. Perfect to see our real-time data feed. No commands needed. Install from here.

Postman (or Insomnia) – point-and-click:

  1. New → WebSocket Request
  2. URL: wss://ws.eodhistoricaldata.com/ws/crypto?api_token=demo
  3. Connect → send: {“action”:”subscribe”,”symbols”:”BTC-USD”}


Python (minimal script):

import asyncio, websockets, json

URL = "wss://ws.eodhistoricaldata.com/ws/crypto?api_token=demo"
async def main():
    async with websockets.connect(URL) as ws:
        await ws.send(json.dumps({"action":"subscribe","symbols":"BTC-USD"}))
        while True:
            print(await ws.recv())

asyncio.run(main())


Mac Os Terminal – websocat (via Homebrew):

Install websocat:

brew install websocat

One-liner command:

printf '{"action":"subscribe","symbols":"BTC-USD"}\n' | \
websocat "wss://ws.eodhistoricaldata.com/ws/crypto?api_token=demo"

Quick Comparison with Live (Delayed) API and Intraday API

AspectReal-Time (WebSockets)Live (Delayed)Intraday Historical
TransportWebSocket (push)HTTPS REST (pull)HTTPS REST (pull)
Latency / Freshness~live (<50 ms transport)Stocks: 15–20 min delay; Currencies: ~1 minFinalized ~2–3 h after US after-hours close
Data typesUS trades & quotes; FX ticks; crypto ticksLatest OHLCV snapshot (1-min updates)OHLCV bars at 1m / 5m / 1h
Time rangesn/a (streaming)n/a (snapshot feed)1m: 120 d · 5m: 600 d · 1h: 7200 d
Markets & assets*US stocks (pre/post supported), Forex & Digital CurrenciesUS & Global Stocks, Forex & Digital CurrenciesUS & Global Stocks, Forex & Digital Currencies
Best forDashboards, signals, market-making toolsQuote tickers, watchlists, lightweight UIsBacktests, analytics, charting

* Get the full list of covered tickers.