Compare Prices Across Venues

Compare prices across venues and find related markets.

Use matching to find cross-venue clusters, then use price helpers or venue exchanges to inspect executable bid/ask data.

compareMarketPrices

Side-by-side bid/ask for the same market on every venue.

This returns a flat side-by-side view for one anchored market. For cluster-first discovery across the whole catalog, use fetchMatchedMarketClusters.

Python

import pmxt

router = pmxt.Router(pmxt_api_key="pmxt_live_...")

prices = router.compare_market_prices(market_id="d35bc8c6-...")

for p in prices:
    print(f"{p.venue:12s}  bid {p.best_bid:.2f}  ask {p.best_ask:.2f}")

polymarket    bid 0.60  ask 0.65
kalshi        bid 0.58  ask 0.63
limitless     bid 0.61  ask 0.66

TypeScript

import pmxt from "pmxtjs";

const router = new pmxt.Router({ pmxtApiKey: "pmxt_live_..." });

const prices = await router.compareMarketPrices({
  marketId: "d35bc8c6-...",
});

for (const p of prices) {
  console.log(`${p.venue.padEnd(12)}  bid ${p.bestBid}  ask ${p.bestAsk}`);
}

Response shape

{
  "market": { "marketId": "...", "title": "..." },
  "relation": "identity",
  "confidence": 0.95,
  "reasoning": "Same resolution condition.",
  "bestBid": 0.60,
  "bestAsk": 0.65,
  "venue": "kalshi"
}

fetchRelatedMarkets

Find related markets across venues — markets whose resolution condition is a subset or superset of the target market.

Python

related = router.fetch_related_markets(market_id="d35bc8c6-...")

for r in related:
    print(f"{r.relation:10s} {r.venue:12s}  {r.market.title}")
    print(f"           confidence {r.confidence:.0%}  bid {r.best_bid}  ask {r.best_ask}")
    print(f"           {r.reasoning}")

subset     kalshi        Will the nominee be from California?
           confidence 85%  bid 0.40  ask 0.45
           Narrower market — California origin implies Democratic candidacy.
superset   polymarket    Will a Democrat win the popular vote?
           confidence 72%  bid 0.70  ask 0.73
           Broader — popular vote does not guarantee election win.

TypeScript

const related = await router.fetchRelatedMarkets({ marketId: "d35bc8c6-..." });

for (const r of related) {
  console.log(r.relation, r.venue, r.market.title);
  console.log(`  confidence: ${r.confidence}  reasoning: ${r.reasoning}`);
}

Subset means A=YES implies B=YES but not vice versa. Superset is the reverse. See relation types for the full taxonomy.

fetchRelatedMarkets filters to subset and superset relations. If you want all relation types, use fetchMatchedMarketClusters with relation or relations filters.

fetchMatchedMarketClusters

Returns matched market clusters across venues. Use this when you want the full group of markets first, then inspect prices and outcomes inside each venue market.

Python

clusters = router.fetch_matched_market_clusters(
    relation="identity",
    sort="volume",
    min_venues=2,
    limit=20,
)

for cluster in clusters:
    print(cluster.canonical_title)
    for market in cluster.markets:
        price = market.yes.price if market.yes else None
        print(f"  {market.source_exchange:12s} @ {price}")

Will BTC hit $100k by Dec 31?
  polymarket   @ 0.58
  kalshi       @ 0.63

TypeScript

const clusters = await router.fetchMatchedMarketClusters({
  relation: "identity",
  sort: "volume",
  minVenues: 2,
  limit: 20,
});

for (const cluster of clusters) {
  console.log(cluster.canonicalTitle);
  for (const market of cluster.markets) {
    console.log(`  ${market.sourceExchange} @ ${market.yes?.price}`);
  }
}

Parameters

Parameter	Type	Default	Notes
relation	string	—	Filter to a relation type such as identity.
minVenues	integer	—	Require at least this many venues in a cluster.
sort	string	volume	Sort by volume or confidence.
limit	integer	50	Maximum number of clusters to return.

Results are cluster-first. PMXT does not pick a best opportunity for you; inspect the returned markets, outcomes, and order books before deciding how to trade.

Response shape

{
  "clusterId": "mcl_...",
  "canonicalTitle": "Will BTC hit $100k by Dec 31?",
  "relations": ["identity"],
  "confidence": 0.98,
  "markets": [
    { "marketId": "pm_...", "sourceExchange": "polymarket", "title": "Will BTC hit $100k by Dec 31?" },
    { "marketId": "kalshi_...", "sourceExchange": "kalshi", "title": "Bitcoin above $100,000 on Dec 31" }
  ]
}

Composing with venue exchanges

The Router is read-only. To trade, use venue-specific exchange classes with the local SDK. A typical workflow:

import pmxt

router = pmxt.Router(pmxt_api_key="pmxt_live_...")
poly   = pmxt.Polymarket(private_key="0x...")

# 1. Browse matched market clusters across venues
clusters = router.fetch_matched_market_clusters(relation="identity", limit=20)

# 2. Inspect the order book on a specific venue
book = poly.fetch_order_book(market_id=clusters[0].markets[0].market_id)

# 3. Place an order locally (never proxied through PMXT)
# poly.create_order(...)

Router returns the same unified schema as every other exchange, so marketId, outcomes, and all other fields work interchangeably.