Live Odds API: Real-Time Odds over WebSocket

// npm i ws
import WebSocket from 'ws'

const API = 'https://api.odds-api.io/v3'
const apiKey = process.env.ODDS_API_KEY
const markets = 'ML,Spread,Totals'
const eventIds = '63017989,63017990' // up to 10, for example from GET /v3/events/live
const bookmakers = 'Bet365,Unibet' // the bookmakers selected on your account
const board = new Map()
let lastSeq = 0
let needsRebuild = false

function connect() {
  const params = new URLSearchParams({ apiKey, markets, eventIds, channels: 'odds,scores,status' })
  if (lastSeq) params.set('lastSeq', String(lastSeq))

  const ws = new WebSocket(`wss://api.odds-api.io/v3/ws?${params}`)

  ws.on('message', (raw) => {
    const msg = JSON.parse(raw)
    if (msg.type === 'resync_required') {
      needsRebuild = true
      return ws.close()
    }
    if (msg.seq > lastSeq) lastSeq = msg.seq
    const key = `${msg.id}:${msg.bookie}`

    if (msg.type === 'created' || msg.type === 'updated') board.set(key, msg.markets)
    if (msg.type === 'deleted' || msg.type === 'no_markets') board.delete(key)
    if (msg.type === 'score') console.log(msg.id, msg.scores.home, msg.scores.away)
  })

  ws.on('error', (err) => console.error('WebSocket error:', err.message || err.code))

  ws.on('close', async () => {
    if (needsRebuild) lastSeq = await rebuildFromRest()
    setTimeout(connect, 2000)
  })
}

// Replay was not possible: reload the subscription from REST and resume from its seq
async function rebuildFromRest() {
  for (let attempt = 1; ; attempt++) {
    try {
      const params = new URLSearchParams({ apiKey, eventIds, bookmakers, markets, includeSeq: 'true' })
      const res = await fetch(`${API}/odds/multi?${params}`)
      const seq = Number(res.headers.get('X-OddsAPI-Seq'))
      if (!res.ok || !(seq > 0)) throw new Error(`snapshot not usable: ${res.status}`)
      const events = await res.json()
      board.clear()
      for (const event of events) {
        for (const [bookie, odds] of Object.entries(event.bookmakers)) board.set(`${event.id}:${bookie}`, odds)
      }
      needsRebuild = false
      return seq
    } catch (err) {
      console.error(`${err.message}, retry ${attempt}`)
      await new Promise((resolve) => setTimeout(resolve, Math.min(30000, 1000 * 2 ** attempt)))
    }
  }
}

connect()

# pip install websockets
import asyncio
import json
import os
from urllib.parse import urlencode

import websockets

params = urlencode({
    "apiKey": os.environ["ODDS_API_KEY"],
    "markets": "ML,Spread,Totals",
    "leagues": "england-premier-league",
    "status": "live",
})

async def main():
    async with websockets.connect(f"wss://api.odds-api.io/v3/ws?{params}") as ws:
        async for message in ws:
            msg = json.loads(message)
            if msg["type"] == "updated":
                for market in msg["markets"]:
                    print(msg["id"], msg["bookie"], market["name"], market["odds"][0])

asyncio.run(main())

{
  "type": "updated",
  "seq": 482917,
  "timestamp": 1723992773,
  "id": "63017989",
  "bookie": "Bet365",
  "markets": [
    {
      "name": "ML",
      "updatedAt": "2026-11-08T15:42:10Z",
      "odds": [{ "home": "1.85", "draw": "3.25", "away": "2.10" }]
    },
    {
      "name": "Totals",
      "updatedAt": "2026-11-08T15:42:10Z",
      "odds": [{ "hdp": 2.5, "over": "1.85", "under": "2.10" }]
    }
  ]
}