Hosted bots

Langbot runs your bot for you, around the clock: as a preview on paper against live markets first, then, when you promote it, on your own Kalshi account. Every change is a version you can roll back to. Today a hosted bot is one of Langbot's built-in strategies with your settings, the markets it may trade, a budget and its guardrails; your own code is coming soon.

Three ways to drive it, all on the same bots:

• Claude, with the Langbot plugin: ask in plain words.
• The web: langbot.ai/app/bots → New bot (pick a strategy, the markets and a budget, deploy a preview), and each bot's page.
• The command line: langbot bots deploy | hosted | promote | rollback | stop | logs.

New here? From Claude to a live bot in 10 minutes.

Previews: paper first

Every new version of a bot starts as a preview: it trades on paper against the live order books Langbot records, with the simulator's fill model (reaction time, depth, queue position) and Kalshi's fees. No money moves. A preview shows its net result after fees, today's result, what it holds, every fill and a log of everything it did.

langbot bots deploy "trump words" --strategy buy_yes_on_first_counting_hit \
  --series KXTRUMPSAY --budget 100 --schedule '{"windows": "calendar", "budget_per_window_usd": 20}'

Which markets

A bot names what it may trade, and keeps picking up matching markets that are listed later:

When it trades

schedule is optional: start_at and end_at (a bot that expires on its own), windows: "calendar" (only around the scheduled events of its markets), recurring windows ({"days": ["mon", "tue"], "start": "09:30", "end": "16:00", "tz": "America/New_York"}) and budget_per_window_usd (at most this much put at risk in each window, for example $20 per speech). Outside its windows a bot opens nothing and cancels its resting orders; it keeps what it holds.

Guardrails

Every bot starts with these on. You can change any of them; you can also switch one off, but only by confirming it by name, because the bot can then lose its whole budget.

The budget is never off: a preview's paper cash, and on a live bot the most it can have at risk (on a sub-account, also all the money it can reach). The kill switch always exists: Stop on the page, stop_bot from Claude, or langbot bots stop. A live bot also stops itself when its positions on Kalshi no longer match what it believes, when an order's state cannot be confirmed, or when its market data goes stale under a resting order.

For several bots, optional fleet limits cap them together: how many may be live, the total at risk, and a combined daily loss that stops every live bot.

How many bots run at once

Your plan sets how many bots may run a preview and how many may run live at the same time, and how far back their logs go. A stopped bot does not count; a new version of a running bot replaces it rather than taking a second place.

Past the limit, a deploy or promote answers 402 with code: quota_exceeded and quota: {dimension: "paper_bots" | "live_bots", plan, used, limit}; stop a bot or upgrade. GET /v1/hosted/bots returns the limits with what is in use. See Pricing and limits.

Live, on your own Kalshi account

Live hosted bots are for Kalshi accounts in the US. Langbot never holds your money and never takes deposits: the bot trades in your Kalshi account, with a key that cannot move money.

Connect Kalshi (one page)

On the bot's page choose Connect Kalshi to go live. This page is the only place a Kalshi key is ever entered; never paste a key into a chat.

Recommended: a sub-account with only the budget. Create an API key in Kalshi (or use the one you have), paste its id and private key, choose a budget and confirm the transfer. With that key, once, Langbot:

1. reads your Kalshi API tier. Kalshi gives sub-accounts to accounts on its Advanced API tier, which requires at least one of your last 100 orders to have been placed through the API; on Basic, Langbot asks Kalshi for the Advanced grant. Langbot never places an order to qualify;
2. creates a new sub-account;
3. moves your budget into it from your main Kalshi balance (once; a retry never moves it twice);
4. creates a new key restricted to that sub-account with only read and write::trade: it can read and trade there and cannot transfer money or manage your account;
5. checks the new key with Kalshi and stores only it, encrypted. The key you pasted is not kept; delete it in Kalshi if you made it for this.

Kalshi itself now caps the bot at the budget.

If your account cannot have sub-accounts yet, the page says so and offers the main account: a key that can only read and trade is created on your main account and nothing is moved. Kalshi then caps nothing; the budget and the stops are Langbot's guardrails. It is labelled as such and must be confirmed. Do not trade by hand on that account while the bot runs: a mismatch stops the bot.

Advanced: your own restricted key. In Kalshi, create the sub-account, move the budget and create a key restricted to it with read and write::trade, then paste it. Langbot refuses a key Kalshi does not accept, a key with any transfer or account permission, and a key that is not restricted to a sub-account (unless you choose the main-account option on purpose).

Go live

Strategies that take liquidity can go live today (the word strategies and buying No on long shots); strategies that rest orders on the book (market making) stay on paper for now.

Once connected, Promote takes the newest preview live as a new live version (the preview keeps running beside it). Every live order goes through the same guard as langbot live run: checked against the guardrails, sent once with a fixed client order id, and written to the bot's log. The live result shown is your Kalshi balance and positions.

How the strategy decides: on Langbot's recorded books and phrase hits, a few seconds behind the exchange; each order is priced from a fresh Kalshi book at the moment it is sent, no more than 3 cents through the best price.

Versions and rollback

Each change is a new deployment: an immutable version of the strategy, settings, markets, budget and guardrails, with its own fills, positions, P&L and log. Promote one, roll back to an earlier one in one step; the page lists them all.

Disconnect

Disconnect on the connect page stops live trading and deletes the stored key. The key itself stays in Kalshi until you delete it there.

How your key is kept

• It is entered only on langbot.ai while signed in. Langbot's API refuses key material from API tokens, so it cannot arrive through the MCP or a chat.
• It is encrypted at rest: a fresh 256-bit data key per bot seals it with AES-256-GCM, and that data key is sealed with Langbot's master key; the record is bound to the bot and your account.
• It is decrypted only by the process that runs live bots, just before it signs a request to Kalshi.
• It is never returned by any API, never shown again and never written to a log.

Bring your own code (coming soon)

Next, a hosted bot can be your own repo or script, in any language. It runs against a Kalshi-compatible paper exchange that Langbot serves on live markets, so the same code that trades on paper is the code you promote, with the same versions, rollback, guardrails and kill switch. Free includes 1 small always-on code bot, Pro 5 and Team 25; extra always-on bots are $5 a month each. This is in beta and not open to everyone yet.

What results mean

Paper results are a simulation on live data; live results are what happened on your account. Neither predicts what comes next, and most strategies lose money after fees. Langbot measures; it does not give advice.