How to Build a Kalshi Sports Betting Bot

Run all four stages on a schedule, several passes per day, so markets that open late still get caught.

1. 01Open a Kalshi account , verify it and fund it.
   Sign up for Kalshi with our link(affiliate link)
2. 02Build and test on Kalshi's demo environment first. Demo credentials are separate from production.
3. 03Create an API key in your Kalshi account settings. Save the private key file right away because Kalshi shows it only once.
4. 04Store the key ID and private key as server-side secrets (environment variables in your host). Never put them in browser code or commit them to git.
5. 05Pick a host that can run on a schedule, for example a serverless function plus a cron job, or a small always-on server.
6. 06Sign every request. Headers: KALSHI-ACCESS-KEY, KALSHI-ACCESS-TIMESTAMP (milliseconds), KALSHI-ACCESS-SIGNATURE. The signature is RSA-PSS SHA-256 over timestamp + HTTP method + path. Sign the path WITHOUT the query string.
7. 07Get picks from your own model. Each pick needs the game, bet type, line, and your model probability.
8. 08Match each pick to a Kalshi market, compute the edge (your probability minus the Kalshi ask price), and queue it only if it passes your limits.
9. 09Place orders, then grade each bet from the settled market result, not from your own score feed.

// Placeholder signing function. No real keys here.
// Check docs.kalshi.com for the current base URLs and endpoints.
import crypto from "node:crypto";

const KEY_ID = process.env.YOUR_KEY_ID;       // your key id, server-side
const PRIVATE_KEY = process.env.YOUR_PRIVATE_KEY; // PEM string, server-side

export function signRequest(method, path) {
  const timestamp = Date.now().toString();
  const message = timestamp + method.toUpperCase() + path; // path WITHOUT query string
  const signer = crypto.createSign("RSA-SHA256");
  signer.update(message);
  const signature = signer.sign(
    { key: PRIVATE_KEY, padding: crypto.constants.RSA_PKCS1_PSS_PADDING, saltLength: crypto.constants.RSA_PSS_SALTLEN_DIGEST },
    "base64"
  );
  return {
    "KALSHI-ACCESS-KEY": KEY_ID,
    "KALSHI-ACCESS-TIMESTAMP": timestamp,
    "KALSHI-ACCESS-SIGNATURE": signature,
  };
}

Check Kalshi's API docs at docs.kalshi.com for the current base URLs and endpoints.

THE LIMITS OUR BOT RUNS WITH

These are our settings, not advice. Size your own unit to your own bankroll.