Polymarket API: fast market data for traders
If you searched for "polymarket api" you want where market data lives and how to use it for fast trading. Polymarket exposes Gamma, Data and CLOB REST APIs plus a market WebSocket for real‑time book and trade events. For arbitrage you need low-latency access, reliable websockets, and tooling that understands CLOB order books and tick sizes. PolyArb connects to the Polymarket APIs, runs on Polygon, and offers a production bot with 40ms latency, Telegram and Discord alerts, and a $7.62 minimum guaranteed edge per trade.
What the Polymarket API surfaces
Polymarket has three REST surfaces: Gamma for markets and events, Data for trades and open interest, and CLOB for order book and order placement. There is also a market WebSocket for live best_bid_ask, price_change and last_trade_price events. These endpoints are the canonical sources for fills, midpoints and tick_size_change messages you need to detect intra-market arbitrage.
Gamma’s /markets is cursor-paginated and rate-limited; CLOB reads are public while CLOB trading requires API keys and HMAC. All trading on Polymarket happens on Polygon using pUSD, and the exchange uses the Gnosis CTF for outcome tokens.
Why latency and message quality matter
Arbitrage windows on Polymarket often last seconds. A few hundred milliseconds of latency can turn a theoretical edge into a missed fill or partial execution. You also need robust handling of tick size tightenings near extremes and UMA resolution pauses.
PolyArb is built to exploit these windows: 40ms median latency versus ~800ms for free bots, non-custodial order routing, and FAK order handling that respects Polymarket’s CLOB semantics.
Practical uses of Polymarket API for arbitrage
Use the WebSocket to subscribe to up to 500 instruments per connection and listen for best_bid_ask and tick_size_change events. Combine that stream with periodic Gamma /markets snapshots to detect when Σ bestAsk(outcome) < $1.00 for multi-outcome or bestAsk(YES)+bestAsk(NO) < $1.00 for binaries.
Account for taker fees (variable by category) and slippage when computing the real edge. The raw price spread is mathematical, but risks remain: UMA disputes, settlement timing, partial fills, and smart-contract risk.
How PolyArb fits your workflow
PolyArb automates detection and execution using the official APIs and the market WebSocket. The service runs live today, is non-custodial, charges $99/month, and provides Telegram + Discord alerts and a $7.62 minimum guaranteed edge per trade when its execution criteria are met.
If you need end-to-end arbitrage—streaming signals, automatic FAK placement through the CLOB, and fast split/merge handling for CTF tokens—PolyArb packages those pieces so you can focus on sizing and operations.
Start capturing Polymarket arbitrage now
Try PolyArb—non-custodial, live today, $99/month, 40ms latency, Telegram and Discord alerts, and a $7.62 minimum guaranteed edge per trade.
FAQ
- What endpoints make up the Polymarket API?
- Polymarket’s public surfaces are Gamma (markets, events), Data (trades, positions, holders), CLOB (order book, prices, trading), and the market WebSocket for real-time events.
- Can I place orders directly through the CLOB API?
- Yes. Reads are public, but trading via the CLOB requires API key + HMAC. Order placement supports limit and FAK market orders and must respect tick sizes and relayer limits.
- Do I need pUSD to trade via the APIs?
- Yes. Polymarket uses pUSD (wrapped USDC on Polygon) as the settlement asset. Polymarket sponsors gas through its Relayer, so users don’t need POL for transactions.
- Is arbitrage with Polymarket API risk-free?
- No. While intra-market edges are mathematical, trades still carry resolution risk (UMA disputes), slippage, partial fills, fee changes, and smart-contract settlement timing risks.