# Polymarket Spread

> Polymarket Spread 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 bid-ask spread for a specific Polymarket prediction market token by token ID.

## Facts

- Endpoint: GET https://api.aisa.one/apis/v1/polymarket/spread?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-spread-c4bd0f7d
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_uhTxH2dTudyRidH5v2ANy

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-spread-c4bd0f7d
```

Example prompt: What's the current bid-ask spread on Polymarket for token ID 71321050856746154452989188028916814621541765919547968739073706498304195102590?

## When to prefer this

Use this endpoint when you need the current bid-ask spread for a specific Polymarket prediction market token and want a lightweight, single-field response. Prefer this over fetching full orderbook data when only the spread metric is needed for liquidity assessment, trading decisions, or market efficiency analysis.

## Known failure modes

- Invalid or non-existent token_id returns an error response
- Missing required token_id parameter results in a 400 bad request
- Network timeout if Polymarket orderbook data is temporarily unavailable
- Token with no active orderbook may return a zero or null spread
- Rate limiting or payment failure may block the request

## How this service works

Retrieves the spread for a specific token ID. The spread is the difference between the best ask and best bid prices.

<!-- 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 JSON object containing the spread as a string (e.g. '0.02'), representing the difference between the best ask and best bid prices for the specified Polymarket token.

## 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": [
  "spread"
 ],
 "properties": {
  "spread": {
   "type": "string",
   "example": "0.02",
   "description": "Spread as a string"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/aisa-mpp-data-apis-polymarket-spread-c4bd0f7d/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)