Dependency-free JavaScript functions that compute taker fees with the shared rate x contracts x p x (1 - p) formula, using each venue's rate, plus an all-in cost per contract. The README explains maker vs. taker fees, Kalshi's round-up to the cent, and per-market Polymarket rates. The author says the tests were checked against real order tickets (self-reported).
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Dependency-free JavaScript functions that compute taker fees with the shared rate x contracts x p x (1 - p) formula, using each venue's rate, plus an all-in cost per contract. The README explains maker vs. taker fees, Kalshi's round-up to the cent, and per-market Polymarket rates. The author says the tests were checked against real order tickets (self-reported). See the source for setup, usage and current status.
Tools: JavaScriptNode.js
Difficulty: beginner
Platforms: Kalshi · Polymarket
Dependency-free JavaScript functions that compute taker fees with the shared rate x contracts x p x (1 - p) formula, using each venue's rate, plus an all-in cost per contract. The README explains maker vs. taker fees, Kalshi's round-up to the cent, and per-market Polymarket rates. The author says the tests were checked against real order tickets (self-reported). It is listed under Data & analytics in this directory.
According to its source, it works with Kalshi and Polymarket.
The source lists: JavaScript, Node.js.
It was published by mrd00807-ux. The public source is at github.com/mrd00807-ux/prediction-market-fees.
This directory rates it beginner (beginner, intermediate or advanced).
It had 0 GitHub stars as of Oct 17, 2026.
The repository was last updated on Oct 17, 2026, as checked on Oct 23, 2026. Check the source for current status.
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