# Polymarket Order Book

> Polymarket Order Book is a paid API for AI agents from AIsa MPP Data APIs at api.aisa.one, paid per call via MPP, $0.012/call, status unknown (last checked 2026-10-18).

Retrieves the current order book summary (bids, asks, last trade price, and market details) for a specific Polymarket prediction market token.

## Facts

- Endpoint: GET https://api.aisa.one/apis/v1/polymarket/book?utm_source=zero.xyz
- Price: $0.012/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-18
- Activations on Zero: 0
- Provider: AIsa MPP Data APIs
- Website: https://aisa.one
- Tags: web-search, financial-data, prediction-markets, weather, travel, data, search
- Canonical page: https://www.zero.xyz/c/aisa-mpp-data-apis-polymarket-order-book-02bdb140
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KMk2Q6STnj7PpmMmF_5ZU

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability aisa-mpp-data-apis-polymarket-order-book-02bdb140
```

Example prompt: What does the order book look like for Polymarket token 12345678901234567890? I want to see the current bids, asks, and last trade price.

## When to prefer this

Use this endpoint when you need real-time order book depth, spread analysis, or last trade price for a specific Polymarket prediction market token. Prefer this over generic market data APIs when working specifically with Polymarket assets identified by token/asset IDs, especially for trading decisions, liquidity checks, or monitoring market microstructure.

## Known failure modes

- Invalid or unknown token_id returns an error or empty result
- Stale snapshot if the market has low activity
- Network timeout if Polymarket API is unresponsive
- Missing token_id parameter results in a validation error
- Expired or delisted market may return no bids or asks

## How this service works

Retrieves the order book summary for a specific token ID. Includes bids, asks, market details, and last trade price.

<!-- aisa-pricing:start -->
Published reference price: $0.012 USD per successful request. Account-specific pricing and final settlement may differ.
<!-- aisa-pricing:end -->

## Output

Returns a structured order book snapshot including an array of bid orders (sorted by price descending) and ask orders (sorted by price ascending), each with price and size strings; plus the market condition ID, asset ID, last trade price, tick size, minimum order size, a boolean neg_risk flag, a timestamp, and a hash of the snapshot.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "token_id"
 ],
 "properties": {
  "token_id": {
   "type": "string",
   "description": "Token ID (asset ID)"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "market",
  "asset_id",
  "timestamp",
  "hash",
  "bids",
  "asks",
  "min_order_size",
  "tick_size",
  "neg_risk",
  "last_trade_price"
 ],
 "properties": {
  "asks": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "price",
     "size"
    ],
    "properties": {
     "size": {
      "type": "string",
      "example": "100",
      "description": "Order size"
     },
     "price": {
      "type": "string",
      "example": "0.45",
      "description": "Order price"
     }
    }
   },
   "description": "List of ask orders (sorted by price ascending)"
  },
  "bids": {
   "type": "array",
   "items": {
    "type": "object",
    "required": [
     "price",
     "size"
    ],
    "properties": {
     "size": {
      "type": "string",
      "example": "100",
      "description": "Order size"
     },
     "price": {
      "type": "string",
      "example": "0.45",
      "description": "Order price"
     }
    }
   },
   "description": "List of bid orders (sorted by price descending)"
  },
  "hash": {
   "type": "string",
   "example": "a1b2c3d4e5f6...",
   "description": "Hash of the order book summary"
  },
  "market": {
   "type": "string",
   "example": "0x1234567890123456789012345678901234567890",
   "description": "Market condition ID"
  },
  "asset_id": {
   "type": "string",
   "example": "0xabc123def456...",
   "description": "Token ID (asset ID)"
  },
  "neg_risk": {
   "type": "boolean",
   "example": false,
   "description": "Whether negative risk is enabled for this market"
  },
  "tick_size": {
   "type": "string",
   "example": "0.01",
   "description": "Minimum price increment (tick size)"
  },
  "timestamp": {
   "type": "string",
   "example": "1234567890",
   "description": "Timestamp of the order book snapshot"
  },
  "min_order_size": {
   "type": "string",
   "example": "1",
   "description": "Minimum order size"
  },
  "last_trade_price": {
   "type": "string",
   "example": "0.45",
   "description": "Last trade price"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/aisa-mpp-data-apis-polymarket-order-book-02bdb140/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.aisa.one](https://www.zero.xyz/host/api.aisa.one/llms.txt)