Get Fee Rate

Returns the fee rate in basis points that applies to a token’s market. The rate comes from the market configuration (fee_bps), so it can differ across Polymarket-synced markets, real-time markets, and template-created markets. Always query it at runtime rather than hard-coding.

Endpoints

Method	Path	Description
GET	/fee-rate?token_id=...	Query parameter variant
GET	/fee-rate/{token_id}	Path parameter variant

Base URL: https://api.openfish.me

Authentication

None required.

Parameters

Parameter	Type	Required	Description
token_id	string	Yes	Token ID (asset ID) — as query param or path param

Response

{
  "base_fee": 10
}

Field	Type	Description
base_fee	integer	Fee rate in basis points

Fee Calculation

The taker fee is calculated as: size * (fee_bps / 10000) * price * (1 - price). Maker fee is zero.

Example

# Query parameter
curl "https://api.openfish.me/fee-rate?token_id=0xabc123..."

# Path parameter
curl "https://api.openfish.me/fee-rate/0xabc123..."