Build on Polymarket smart-money data

Overview

The API exposes real-time large Polymarket trades by tracked whales, current arbitrage (mispriced multi-outcome markets) with net edge, an Insider-Score leaderboard, a copy-the-top-insiders backtest, and admin-mapped cross-venue (Polymarket vs Kalshi) pairs.

It is a premium-only feature: keys are issued to accounts with an active subscription and stop working when the subscription lapses. Responses are full-fidelity — unmasked wallet addresses, trade direction and exact prices.

Base URL: all endpoints live under /api/v1 and return JSON.

Authentication

• Pass your key as a bearer token: Authorization: Bearer wi_… (an X-API-Key: wi_… header also works).
• Generate and revoke keys below. A key’s secret is shown only once at creation — store it securely.
• Keep keys server-side. Never embed them in a browser or mobile app you ship to users.

Rate limits & errors

• Each key is capped per day; the X-RateLimit-Limit and X-RateLimit-Remaining response headers report your budget. Over the cap returns 429.
• Errors are JSON: 401 missing/invalid key, 402 subscription lapsed, 429 rate-limited, 500 server error.
• Poll politely — the whale feed supports a `since` cursor so you only fetch new trades.

Endpoints

Prices are 0–1 probabilities. usdValue is the trade’s USD notional. Timestamps are ISO-8601 UTC.

Quick start

Replace wi_YOUR_KEY with your key. Every call is a GET.

curl -H "Authorization: Bearer wi_YOUR_KEY" \
  "https://whalesinsider.com/api/v1/whales/recent?minUsd=10000&limit=20"

const r = await fetch("https://whalesinsider.com/api/v1/forks?minEdge=0.02", {
  headers: { Authorization: "Bearer wi_YOUR_KEY" },
});
const { forks } = await r.json();
console.log(forks[0]); // { eventTitle, netEdgePct, legs, ... }