Polymarket Intelligence & Odds API

Clean, structured, and real-time data access to the world’s largest prediction market. Extract implied probabilities, trading volumes, bid-ask spreads, and Central Limit Order Book (CLOB) contract identifiers directly from Polymarket.

Designed specifically for algorithmic trading desks, prediction market makers, quantitative researchers, and autonomous AI agents.

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Why Use This Actor?

Polymarket has become the primary real-time consensus engine for geopolitical shifts, Federal Reserve interest rate expectations, national elections, and macro economic milestones.

However, integrating Polymarket's raw catalog into automated trading infrastructure introduces repetitive engineering friction:

1. Stringified JSON payloads: Essential fields like outcomePrices and clobTokenIds are returned as escaped JSON strings, requiring manual JSON parsing on every item.
2. Disconnected data structures: Single-contract markets and multi-outcome events are nested differently across distinct endpoints.
3. Missing trading metrics: Raw responses do not compute relative bid-ask spreads, basket fair-value deviations, or percentage implied probabilities.

This Actor standardizes the entire data pipeline into typed, predictable JSON records ready for immediate programmatic consumption in sub-second execution time.

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Three Dedicated Operational Endpoints

Configure the mode parameter to match your workflow:

Endpoint Mode	Focus	Practical Use Case
Top Trending & Whales (trending)	Top liquid markets ranked by USD volume	Macro sentiment monitors, whale volume trackers, high-liquidity dashboards
Search by Topic (search)	Keyword, ticker, or candidate lookup	News-driven trade triggers, automated event verification, research feeds
Dutch-Book & Spread Scanner (arbitrage_scanner)	Dislocated odds and wide bid-ask spreads	Statistical arbitrage, market making, negative-risk basket capture

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Key Output Capabilities

• Direct CLOB Token Identifiers: Every outcome includes its raw Polygon ERC-1155 clobTokenId, allowing your bots to immediately route limit or market orders via Polymarket's Exchange API.
• Spread & Liquidity Metrics: Automatically computes bestBid, bestAsk, absolute spreadUsd, and spreadRelativePct (cost to cross the spread), highlighting market making and liquidity-harvesting opportunities.
• Pre-computed Implied Probabilities: Converts decimal pricing into percentage odds for binary (Yes/No) and multi-candidate events.
• Dutch-Book Dislocation Detection: Flags when an outcome basket deviates from $1.00 fair value, identifying discount profit margins.
• AI Agent Native: Zero-fluff JSON schema optimized for tool calling across LangChain, AutoGen, CrewAI, and OpenAI function calling.

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Input Parameters

Parameter	Type	Default	Description
mode	Select	trending	Choose trending, search, or arbitrage_scanner.
searchQuery	String	"Federal Reserve"	Search term or ticker (used when mode is search).
maxItems	Number	20	Maximum number of market contracts to return (1–200).
minVolumeUsd	Number	1000	Filter out illiquid markets below a specified total volume floor.
activeOnly	Boolean	true	Only return markets currently open and accepting orders.

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Standardized JSON Output

{
  "id": "559652",
  "question": "Will Gavin Newsom win the 2028 Democratic presidential nomination?",
  "eventTitle": "Democratic Presidential Nominee 2028",
  "slug": "democratic-presidential-nominee-2028",
  "url": "https://polymarket.com/event/democratic-presidential-nominee-2028",
  "category": "Politics",
  "volumeTotalUsd": 27759450.56,
  "volume24hrUsd": 9533.74,
  "liquidityUsd": 184500.0,
  "bestBid": 0.152,
  "bestAsk": 0.153,
  "spreadUsd": 0.001,
  "spreadRelativePct": 0.66,
  "outcomes": [
    {
      "outcome": "Yes",
      "priceUsd": 0.1525,
      "impliedProbabilityPct": 15.25,
      "clobTokenId": "106229668102716149832209250222340847662201251266419359322746795373714233470739"
    },
    {
      "outcome": "No",
      "priceUsd": 0.8475,
      "impliedProbabilityPct": 84.75,
      "clobTokenId": "33007765079325382103458898680383691503895532108499178620460955049586020382226"
    }
  ],
  "sumOfPrices": 1.0,
  "isMispriced": false,
  "mispricingEdgePct": 0.0,
  "mispricingType": "fair",
  "endDate": "2028-11-08T00:00:00Z",
  "active": true,
  "closed": false,
  "scrapedAt": "2026-09-27T00:00:00.000Z"
}

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Code Examples

Python (apify-client)

from apify_client import ApifyClient

client = ApifyClient("YOUR_APIFY_TOKEN")

# Run the Dutch-Book & Spread Scanner
run = client.actor("nfa2026/polymarket-odds-intelligence").call(
    run_input={
        "mode": "arbitrage_scanner",
        "maxItems": 25,
        "minVolumeUsd": 5000,
    }
)

for contract in client.dataset(run["defaultDatasetId"]).iterate_items():
    print(f"Contract: {contract['question']}")
    print(f"Spread: ${contract.get('spreadUsd')} ({contract.get('spreadRelativePct')}%) | Volume: ${contract.get('volumeTotalUsd'):,.0f}")

Node.js / TypeScript

import { ApifyClient } from 'apify-client';

const client = new ApifyClient({ token: 'YOUR_APIFY_TOKEN' });

// Fetch top trending markets
const run = await client.actor('nfa2026/polymarket-odds-intelligence').call({
    mode: 'trending',
    maxItems: 10,
});

const { items } = await client.dataset(run.defaultDatasetId).listItems();
console.log(items);

Model Context Protocol (MCP) for AI Agents

Integrate live prediction market discovery directly into Claude Desktop, Cursor, or custom LLM agent pipelines:

{
  "mcpServers": {
    "polymarket": {
      "command": "npx",
      "args": [
        "-y",
        "@apify/mcp-server",
        "--actors",
        "nfa2026/polymarket-odds-intelligence"
      ]
    }
  }
}

cURL

curl -X POST "https://api.apify.com/v2/acts/nfa2026~polymarket-odds-intelligence/run-sync-get-dataset-items?token=YOUR_APIFY_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"mode": "trending", "maxItems": 5}'