# Polymarket Fee Rate Lookup

> Polymarket Fee Rate Lookup 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 base fee rate (in basis points) for a specific Polymarket token/asset ID.

## Facts

- Endpoint: GET https://api.aisa.one/apis/v1/polymarket/fee-rate?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-fee-rate-lookup-5b05b1c2
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_s_yt3TJOv2EbLXy3lDpOi

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-fee-rate-lookup-5b05b1c2
```

Example prompt: What's the base fee rate for the Polymarket token with ID 0x1234abc? I want to know how many basis points I'll be charged before I trade.

## When to prefer this

Use this endpoint when you need to look up the exact trading fee for a specific Polymarket token before executing or analyzing a trade, or when building tools that calculate net returns or costs on prediction market positions. Prefer this over scraping Polymarket's frontend or using general financial data APIs that don't cover prediction market fee structures.

## Known failure modes

- Missing or invalid token_id returns an error response
- Token ID not found on Polymarket returns a not-found error
- Network timeout or upstream Polymarket API unavailability
- Malformed token_id string causing a parsing error

## How this service works

Retrieves the base fee rate for a specific token ID. The fee rate can be provided either as a query parameter or as a path parameter.

<!-- 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 `base_fee`, an integer representing the base fee rate in basis points (e.g., 30 = 0.30%) that Polymarket charges for trading the specified token.

## Request schema (JSON Schema)

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

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "base_fee"
 ],
 "properties": {
  "base_fee": {
   "type": "integer",
   "format": "int64",
   "example": 30,
   "description": "Base fee in basis points"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/aisa-mpp-data-apis-polymarket-fee-rate-lookup-5b05b1c2/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)