A Polymarket trading bot is a program that reads prices on Polymarket, applies rules you set, and places or skips orders for you. This guide explains how one works on the 15-minute crypto Up/Down markets, what it has to hold to sign orders, how to run it alongside Kalshi, and what to check before you trust one with money. API and fee details come from Polymarket's and Kalshi's published docs as of October 2026. Docs change, so re-check before you trade.
The short version
- What it does: watches the order book, checks your rules (price band, time left, budget), then places, skips or exits, and records why.
- What it needs: API credentials created from your wallet signature. Anything that can sign for your wallet can trade your balance, so where the bot runs matters.
- Fees: Polymarket's taker fee on crypto markets is C × 0.07 × P × (1 − P), the same shape as Kalshi's. At 50¢ that's $1.75 per 100 contracts. Makers pay nothing.
- Access: Polymarket's developer docs list the United States as close-only on the international exchange. Check that Polymarket is available where you live before you run anything.
- Reality check: a bot only applies rules faster and more consistently. It doesn't create an edge. Most short-dated strategies lose after fees.
How a Polymarket bot works, step by step
- Find the market. The 15-minute crypto markets ask whether a coin such as BTC or ETH will finish the window up or down. A new one opens every 15 minutes, so the bot has to find the current market on every cycle.
- Read the book. It pulls the best bid and ask and the depth for Up and Down. Prices run from 1¢ to 99¢, and a winning share pays $1.
- Compare against a live price. A useful bot also watches the coin's spot price from outside sources and asks a simple question: with this much time left, how far is spot from the opening price?
- Apply your rules. Typical rules cover the price band (for example, only favorites between two prices), a minimum time left, a stake per trade, a daily budget and a maximum number of open positions.
- Place or skip, and log the reason. Most windows should be skips. A log that says why it skipped is as useful as one that says why it traded.
- Settle and record. The market resolves at the end of the window. The bot records the win or loss, including fees, so you can see real results rather than a highlight reel.
Where the bot runs matters more than the strategy
Polymarket API keys are created by signing with your wallet, and requests are then signed with HMAC-SHA256. In practice that means a hosted "cloud bot" needs a credential that can trade your balance. There are three common setups:
| Setup | Who holds the signing credential | Main risk |
|---|---|---|
| Hosted / cloud bot | The service's servers | You're trusting their security and honesty with your balance |
| Copy-trading bot | Usually the service | You inherit someone else's entries, sizing and timing, with a delay |
| Self-hosted / desktop bot | Your own computer | You're responsible for keeping the computer on, updated and secure |
For most people, keeping the credential on their own computer is the safer default. Whatever you choose, never paste a private key or seed phrase into a website, chat or form.
Running Polymarket and Kalshi side by side
Both venues list short-dated crypto markets, and the same question can trade at different prices on each. That's useful information even if you only trade one venue. If Kalshi prices an outcome at 92¢ and Polymarket at 85¢, one of them is probably wrong about something, and that's a reason to look twice before buying the more expensive side. It isn't free money. The markets often settle on different reference prices and windows, fees apply on both sides, and the gap can close before you're filled. For the full API, fee and access comparison, see Kalshi vs Polymarket for automated trading.
Fees decide whether a strategy can work
The taker fee is largest near 50¢ and smallest near the edges, but cheap favorites still need a very high win rate. Buying at 92¢ risks 92¢ to make 8¢ before fees, so a single loss wipes out about eleven wins. Work out your break-even before you switch anything to live. Our break-even win-rate guide walks through the math at every price, and the same logic applies on Polymarket's crypto markets.
8 things to check before you run a Polymarket bot
- Access: are you allowed to trade Polymarket from where you live?
- Credentials: does the bot run on your machine, or does a server hold something that can trade your balance?
- Paper mode: can you run it on paper first, with the same rules?
- Loss limit: is there a daily loss pause that stops new entries automatically?
- Per-market switches: can you turn single markets on or off without stopping everything?
- Reasons: does it log why it traded and why it skipped?
- Honest results: does it show losses and fees, with dates, rather than just winning screenshots?
- Exit: can you cancel without a contract or fee, and does it keep working until the end of the paid period?
We wrote a longer version for Kalshi bots, which applies here too: Kalshi trading bot checklist. Paper results also tend to look better than live ones, and this article explains why.
Where DeskBot fits
DeskBot is a desktop app for Windows and Mac that runs on your own computer with your own API keys, so it never holds your funds. One subscription includes:
- A Polymarket section: a separate lane for the 15-minute crypto Up/Down markets on your own Polymarket account, with its own status, ledger and limits.
- A Kalshi desk: 19 fifteen-minute markets (crypto, metals, energy and currencies), with a normal lane and a second chart-driven lane called S2.
- A cross-check: Kalshi and Polymarket side by side in one dashboard, so each pick is checked against the other venue's price.
- Combos and parlays: a desk for multi-leg Kalshi combos, kept inside your stake and budget limits.
- Multi-account: a lead account plus copy accounts, each with its own key, ledger and daily loss pause.
- Controls: paper mode, a live switch for each market, a daily loss pause, and a written reason for every trade and every skip.
It costs $19.99 a month, and you can cancel anytime. See DeskBot and subscribe.
FAQ
Is a Polymarket bot allowed?
Polymarket publishes a public trading API for programmatic orders. Whether you can use it depends on where you live. Its docs list the United States as close-only on the international exchange, so check its current terms and geoblock rules for your location.
Do Polymarket bots make money?
Some strategies do for a while, and many don't. A bot can't fix a strategy that loses after fees. It just runs that strategy faster. Anyone who promises steady profits is selling the promise, not the bot.
What's the difference between a Polymarket bot and a copy-trading bot?
A rules bot trades from rules you set. A copy-trading bot mirrors another wallet's trades, usually with a delay and often at worse prices than the original.
Can one app trade Kalshi and Polymarket?
Yes, as long as each account is yours and the venue is available to you. DeskBot runs them as separate sections with separate keys, ledgers and limits, and shows both in one dashboard.
Does DeskBot hold my funds or keys?
No. It runs on your computer, and your keys stay there. Your money stays in your own exchange account.
Risk: Trading on Polymarket or Kalshi can lose money, and fees make short-dated strategies harder to win. There are no guaranteed results, and past or paper results don't guarantee future results. DeskBot is not affiliated with, endorsed by or sponsored by Kalshi or Polymarket. Fee and API details were taken from each venue's published documentation in October 2026, so check the current terms before trading.