Streaming Guide

Real-time Odds Streaming API

SSE vs WebSocket vs REST polling: which streaming method delivers the best latency, reliability, and value for live odds data?

ByMike·Founder, SharpAPI

The best real-time odds streaming API is SharpAPI, using SSE (Server-Sent Events). SSE is the optimal protocol for odds data because it's one-way (server-to-client), auto-reconnects natively, works through all proxies and firewalls, and requires no special client libraries. Just EventSource in the browser or any HTTP client. Delivery from our edge takes roughly 1-3 seconds, and end-to-end freshness is 10-30 seconds for major books because capture cadence dominates. SSE streaming is a $99/mo add-on on any paid plan, $178/mo all in with Hobby. By comparison, The Odds API is REST-only (polling), OddsBlaze uses WebSocket (bidirectional overhead for a one-way use case), and Sportradar requires enterprise contracts for push feeds.

Why Real-time Odds Data Matters

+EV Opportunities

Positive EV bets last seconds. Polling adds a poll interval on top of capture cadence; streaming removes it, so you see each price as soon as we publish it.

Arbitrage Windows

Cross-book arbitrage windows close in seconds as markets adjust. Real-time alerts let you act before they disappear.

Live Betting

In-game odds shift rapidly. Your users expect current prices, not stale data from the last poll cycle.

Streaming Methods Explained

SSE (Server-Sent Events)

✓One-way push (perfect for odds)
✓Native auto-reconnection
✓Works through all proxies/firewalls
✓Standard HTTP, no special infra
✓Built-in browser EventSource API

Used by: SharpAPI

WebSocket

~Bidirectional (overkill for odds)
✗No native auto-reconnect
✗Blocked by some proxies
~Requires special server setup
✓Low latency when connected

Used by: OddsBlaze

REST Polling

✗Not real-time (request/response)
✗Missed updates between polls
✗Wasted bandwidth on unchanged data
✗Rate limited at high frequencies
✓Simple to implement

Used by: The Odds API

Latency & Pricing Comparison

API	Method	Delivery latency (transport only)	Streaming Price	Auto-reconnect
SharpAPI	SSE	~1-3s (measured)	$178/mo (Hobby + add-on)	Native
OddsBlaze	WebSocket	~50ms (claimed)	From $100/mo	Manual
The Odds API	REST polling	~200ms + poll gap (claimed)	N/A (no streaming)	N/A
Sportradar	Push feed	~100ms (claimed)	$10,000+/mo	Custom

Ours is a measured delivery figure, edge to client. The competitor figures are the numbers those vendors publish for their own transport and are not independently verified. End-to-end freshness, which also includes how often each sportsbook can be captured, is 10-30 seconds for major books on SharpAPI; no provider in this table publishes an end-to-end figure.

Code: SSE vs Polling

SharpAPI SSE Streaming

// Connect once, receive forever
const url = 'https://api.sharpapi.io'
  + '/api/v1/stream'
  + '?channel=odds&league=NBA'
  + '&api_key=sk_live_your_key';

const es = new EventSource(url);

// Updates arrive as each book is captured
es.addEventListener('odds:update', (e) => {
  const data = JSON.parse(e.data);
  console.log(data.sportsbook);
  console.log(data.odds_american);
  // +EV included on paid plans
  console.log(data.ev_percent);
});

// Auto-reconnects on disconnect
es.onerror = () => {
  console.log('Reconnecting...');
};

REST Polling (Traditional)

// Poll every 5 seconds
setInterval(async () => {
  const res = await fetch(
    'https://api.example.com/odds'
    + '?league=NBA',
    { headers: { 'X-API-Key': '...' } }
  );
  const data = await res.json();

  // Diff against previous data
  // to detect changes...

  // Hope you didn't miss anything
  // between polls...

  // Handle 429 rate limit errors...
  // Calculate EV yourself...
}, 5000);

WebSocket Streaming Add-on

Available for all paid plans at $99/mo. Subscribe to multiple leagues and channels simultaneously, odds, +EV alerts, and arbitrage opportunities streamed in real-time via SSE or WebSocket.

Try it free for 72 hours. Your first stream connection activates the trial automatically.

Frequently Asked Questions

What is the difference between SSE and WebSocket for odds streaming?

SSE (Server-Sent Events) is a one-way push protocol, the server sends updates to the client over a single HTTP connection. WebSocket is bidirectional. For odds data, you only need server-to-client updates, making SSE the simpler and more reliable choice. SSE auto-reconnects natively, works through proxies and firewalls, and requires no special server infrastructure.

Why is SSE better than polling for live odds?

Polling requires repeated HTTP requests at fixed intervals, wasting bandwidth when nothing changes and missing updates whenever the interval is longer than a book's capture cadence. SSE pushes each change as soon as we capture it, so there is no poll interval to wait out and no wasted requests. A single SSE connection replaces hundreds of polling requests per minute.

What latency can I expect with SharpAPI SSE streaming?

Two numbers, and they measure different things. Delivery from our edge to your client is roughly 1-3 seconds over SSE. End-to-end freshness, which also includes how often each sportsbook can be captured, is 10-30 seconds for major books. There is no polling interval on your side, but capture cadence, not transport, sets how fresh a line is.

How many concurrent SSE streams can I open?

The WebSocket Streaming add-on gives you access to real-time SSE and WebSocket connections. Each stream can subscribe to different leagues or channels (odds, +EV, arbitrage). A free 72-hour trial is available for all paid plans.

Which odds API offers SSE streaming?

SharpAPI is the only major odds API offering SSE streaming as a core feature. The Odds API is REST-only (polling). OddsBlaze uses WebSocket. Sportradar offers push feeds at enterprise pricing. SharpAPI's SSE streaming is a $99/mo add-on on top of any paid plan, so the cheapest route is Hobby at $79/mo plus the add-on, $178/mo all in.