Election night, replayable
Replay the 2026 US midterms on the headline Kalshi and Polymarket election markets and crash-test your bot against the order books that were really there, fees included.
The markets
House and Senate control and the balance of power, on both venues. The closest Senate and governor races, as priced at 5:00 pm ET, with the same race on Polymarket where the two markets are linked. Then the other election markets with the most recorded activity that night, up to 60 in all.
One clock
Every recorded book change on every market plays back on the same clock, so you can watch Kalshi and Polymarket move side by side. The only marks on the clock are the scheduled poll-closing times by state; there is no transcript and no race calls.
A real test
A strategy trades against the recorded depth after your reaction time, pays the venue fees, waits its place in the queue if you ask it to, and is scored at each slower timing too. Each run is one simulator run on your plan.
Run your own bot on it
In the app, pick a built-in such as making a market on every listed market, and compare it with doing nothing. Your own code runs on your machine with the same engine and the same scorecard; the SDK is MIT-licensed.
pip install langbot-sdklangbot sim eventslangbot sim run --event ev_us-midterms-2026-night --strategy my_bot.pyPoll-closing times are the latest scheduled time in each state, in Eastern time, as published by 270toWin; some polling places close earlier. Prices are the venues' own recorded books. Markets settle on each venue's rules, not on Langbot. Nothing here is a forecast or a recommendation.