Polymarket CLOB Order Book Scraper

Collect full depth-of-book data from the Polymarket Central Limit Order Book (CLOB) API for one or more market-outcome token IDs. This Apify actor returns every bid and ask at every price level — not just the top-of-book best bid/ask — along with order book metadata, a deterministic content hash, and an execution timestamp.

It is the only Apify actor that surfaces complete CLOB order book depth. It is built for quants, market makers, prediction-market researchers, and data engineers who already know which token IDs they care about and want precision data without per-result charges.

Why use this actor?

• Full order book depth — not just the top — every bid and ask at every price level, returned as structured arrays of {price, size}. No other Polymarket actor on Apify provides this data.
• Free and open source — no per-result pricing, no result caps, no trial limits. Use it for research, analytics, or production pipelines without a usage meter.
• Deterministic content hash — every output record includes a SHA-256 hash of the canonical order book JSON, computed using the same ordering logic as Polymarket's own OrderBookSummary.dumps(). Verify data integrity or detect changes without re-parsing the full depth.
• Token-ID-native workflow — works directly with Polymarket's core identifier. Input a token ID, get its order book. No market discovery, no category browsing, no noise.
• CLOB metadata — tick_size, min_order_size, and neg_risk are included in every record, giving you the trading parameters that govern the market.
• HTTP/2 transport — efficient API communication with the Polymarket CLOB REST endpoint.
• Adaptive concurrency — processes multiple token IDs in parallel with cgroup-aware memory management, adjusting throughput to the available resources.
• Consistent dataset output — every record follows the same predictable top-level structure, making it straightforward to ingest into downstream pipelines.

What you can collect

Each output record includes the following fields from the Polymarket CLOB /book endpoint:

Category	Fields
Market identity	market (hex market address), asset_id (token ID)
Order book depth	bids[] (array of {price, size} at every price level), asks[] (array of {price, size} at every price level)
Trading parameters	tick_size, min_order_size, neg_risk
Price reference	last_trade_price (null when no trades exist)
Data integrity	hash (SHA-256 of canonical order book JSON)
Temporal	timestamp (Unix milliseconds as a string)

Input

Provide one or more Polymarket CLOB token IDs in tokenIds. The field is required. An optional host override lets you point at a different CLOB API endpoint.

Field	Type	Required	Default	Description
tokenIds	Array of strings	Yes	—	One or more Polymarket CLOB outcome token IDs. Each token ID is a long numeric string identifying a specific market outcome.
host	String	No	https://clob.polymarket.com	Override the CLOB API host URL.

Example input

{
  "tokenIds": [
    "78433024518676680431174478322854148606578065650008220678402966840627347604025"
  ]
}

To collect order books for multiple outcomes in a single run, add more token IDs to the array:

{
  "tokenIds": [
    "78433024518676680431174478322854148606578065650008220678402966840627347604025",
    "12345678901234567890123456789012345678901234567890123456789012345678901234"
  ]
}

Token IDs can be obtained from market-discovery actors that surface token_yes / token_no fields, or directly from the Polymarket CLOB API.

Output

The actor pushes one dataset item for each successfully retrieved order book. A representative result looks like this:

{
  "market": "0x384e2707bbb95da4bfa6f330fe7d5ccbec1c0a85e20be900cbf599987588e1a4",
  "asset_id": "78433024518676680431174478322854148606578065650008220678402966840627347604025",
  "timestamp": "1786095435937",
  "hash": "9439526444ec82ddfca74965d5668a024c7e4ba1a3fe9e084ceb0f78b7c8303b",
  "bids": [
    { "price": "0.01", "size": "1111" },
    { "price": "0.02", "size": "6.12" },
    { "price": "0.03", "size": "120" }
  ],
  "asks": [
    { "price": "0.99", "size": "40006.78" },
    { "price": "0.97", "size": "4000" },
    { "price": "0.96", "size": "8.1" }
  ],
  "min_order_size": "5",
  "tick_size": "0.01",
  "neg_risk": false,
  "last_trade_price": "0.110"
}

The example is abbreviated. A real order book can contain many more price levels on each side. last_trade_price is null when no trades have occurred. The hash field is always present and reflects the full canonical order book, not a truncated view.

Built for practical workflows

• Market making and HFT signal pipelines — consume full depth to build or calibrate pricing models.
• Liquidity monitoring — track bid/ask depth changes across tokens over time with scheduled runs.
• Data integrity verification — use the deterministic hash to confirm data hasn't been altered in transit or storage.
• Prediction-market research — collect order book snapshots for academic or industry analysis of prediction-market microstructure.
• Arbitrage scanning — pair with cross-platform price feeds to identify discrepancies between Polymarket CLOB pricing and other venues.
• Complementary discovery workflow — use a market-discovery actor to find token IDs, then feed them into this actor for depth. The token_yes and token_no fields from market-level scrapers map directly to the tokenIds input here.

How to run

1. Open the actor in Apify.
2. Add one or more Polymarket CLOB token IDs to tokenIds.
3. Optionally override the host if you need a different CLOB API endpoint.
4. Start the run.
5. Review the dataset or export it as JSON, CSV, Excel, or another supported format.

Important limitations

• No market discovery — this actor requires token IDs as input. It cannot search markets by keyword, browse categories, or filter by volume. Pair it with a market-discovery scraper if you need to find token IDs first.
• No market context — the output does not include event titles, market questions, descriptions, categories, images, or resolution criteria. It returns raw CLOB data only.
• No volume or liquidity aggregation — the actor does not compute or return total volume, 24-hour volume, or liquidity metrics. Those fields are available from market-level scrapers.
• Sequential token-ID calls — each token ID results in a separate /book API call. Very large batches may take proportionally longer.
• No WebSocket streaming — this is a snapshot actor, not a real-time stream. Each run captures the order book state at the time of the API call.
• Public API only — the actor uses Polymarket's public CLOB REST endpoint. No authentication or account-level data is involved.

The actor is read-only and uses only the public Polymarket CLOB API. Use the collected information in accordance with Polymarket's terms of service and your organization's data-use policies.