Build on prediction market data

The most mispriced markets right now — our model’s fair value vs. the live price, ranked by edge size. Returns one row per market, deduplicated to the latest reading.

Query parameters

Response: edges[]

Example

curl "https://api.marketmaster.live/v1/edges?platform=kalshi&limit=2" \
  -H "x-api-key: mmk_live_your_key_here"

const res = await fetch(
  "https://api.marketmaster.live/v1/edges?platform=kalshi&limit=2",
  { headers: { "x-api-key": process.env.MM_API_KEY } }
);
const { edges } = await res.json();

import requests
r = requests.get(
    "https://api.marketmaster.live/v1/edges",
    params={"platform": "kalshi", "limit": 2},
    headers={"x-api-key": MM_API_KEY},
)
edges = r.json()["edges"]

{
  "count": 2,
  "edges": [{
    "platform": "kalshi", "market_id": "PRES-2028-DEM",
    "market_title": "Will a Democrat win the 2028 election?",
    "outcome": "YES", "price": 0.43, "fair_value": 0.51,
    "edge_pct": 8.0, "confidence": 0.62,
    "expires_at": "2028-11-07T05:00:00Z", "computed_at": "2026-06-20T21:25:12Z"
  }],
  "generated_at": "2026-06-20T21:25:34Z"
}

The latest snapshot of all tracked markets across both venues — title, category, YES/NO price, 24h volume, and close time. Sorted by 24h volume (most active first).

Query parameters

Response: markets[]

curl "https://api.marketmaster.live/v1/markets?category=politics&limit=50" \
  -H "x-api-key: mmk_live_your_key_here"

A single market’s latest snapshot plus any live edges computed for it. Identify by source + id.

Query parameters

Returns market (same shape as markets[]) and edges[] (same shape as edges[], most recent first). Unknown id returns 404 not_found.

curl "https://api.marketmaster.live/v1/market?source=kalshi&id=PRES-2028-DEM" \
  -H "x-api-key: mmk_live_your_key_here"

Cross-platform price spreads for the same outcome on matched markets, ranked widest first.

Query parameters

Response: opportunities[]

curl "https://api.marketmaster.live/v1/arbitrage?min_spread=2&limit=10" \
  -H "x-api-key: mmk_live_your_key_here"

Recent large real-money trades across venues, newest first.

Query parameters

Response: trades[]

curl "https://api.marketmaster.live/v1/whales?min=10000&limit=20" \
  -H "x-api-key: mmk_live_your_key_here"

Returns your key’s tier, limits, and current usage. Use to monitor remaining quota.

{
  "ok": true,
  "tier": "free",
  "limits": { "minute": 60, "month": 1000 },
  "usage":  { "minute": 3,  "month": 412 }
}

Connection URL

wss://api.marketmaster.live/api/v1/stream

Authentication

Your API key must be sent at connection time. Two options depending on environment:

Channels

Client → server messages (send as JSON)

Server → client messages (receive as JSON)

Connection limits by tier

Example — browser

// Pass key as query param; browsers can't set WebSocket headers
const ws = new WebSocket(
  `wss://api.marketmaster.live/api/v1/stream?api_key=${MM_API_KEY}`
);

ws.onopen = () => {
  ws.send(JSON.stringify({ action: "subscribe", channel: "edges"  }));
  ws.send(JSON.stringify({ action: "subscribe", channel: "whales" }));
};

ws.onmessage = async (e) => {
  const msg = JSON.parse(e.data);
  if (msg.type === "event" && msg.channel === "edges") {
    // New edge batch — pull fresh data
    const { edges } = await fetch("/v1/edges?limit=20", {
      headers: { "x-api-key": MM_API_KEY }
    }).then(r => r.json());
    renderEdges(edges);
  }
};

// Keep-alive ping every 30s
setInterval(() => ws.send(JSON.stringify({ action: "ping" })), 30_000);

Example — Node.js

import WebSocket from "ws";

const ws = new WebSocket("wss://api.marketmaster.live/api/v1/stream", {
  headers: { "x-api-key": process.env.MM_API_KEY },
});

ws.on("open", () => {
  ws.send(JSON.stringify({ action: "subscribe", channel: "edges"  }));
  ws.send(JSON.stringify({ action: "subscribe", channel: "whales" }));
});

ws.on("message", (raw) => {
  const msg = JSON.parse(raw);
  console.log(msg.type, msg.channel ?? "", msg.data ?? "");
});

Example — Python

import asyncio, json, websockets

async def stream():
    uri = "wss://api.marketmaster.live/api/v1/stream"
    async with websockets.connect(uri, extra_headers={"x-api-key": MM_API_KEY}) as ws:
        await ws.send(json.dumps({"action": "subscribe", "channel": "edges"}))
        await ws.send(json.dumps({"action": "subscribe", "channel": "whales"}))
        async for raw in ws:
            msg = json.loads(raw)
            print(msg["type"], msg.get("channel"), msg.get("data"))

asyncio.run(stream())