Kalshi TypeScript kickoff

TypeScript boilerplate for the Kalshi API: REST (via official SDK) and optional WebSocket/Express server.

Setup

cp .env.sample .env
# Edit .env: set KALSHI_API_KEY and either KALSHI_PRIVATE_KEY_PATH or KALSHI_PRIVATE_KEY_PEM
npm install

Scripts

• npm run run – Run the main script (e.g. fetch balance via REST).
• npm run bot – Run the Bitcoin up/down trading bot (see below).
• npm run monitor – Run real-time price monitor for UP/DOWN best bid/ask (see below).
• npm start – Start the Express server (default port 5000).
• npm run build – Compile TypeScript to dist/.

Environment

Variable	Description
KALSHI_API_KEY	Your Kalshi API key id.
KALSHI_PRIVATE_KEY_PATH	Path to your RSA private key .pem file.
KALSHI_PRIVATE_KEY_PEM	Alternatively, the PEM string (e.g. from a secret manager).
KALSHI_DEMO	Set to true to use the demo API.
KALSHI_BASE_PATH	Optional override for API base URL.

Real-time price monitor

Monitor best bid/ask for UP (YES) and DOWN (NO) tokens on the first open Bitcoin 15m market. Use this to decide which side to buy for profit.

Env vars

Variable	Description
KALSHI_MONITOR_INTERVAL_MS	Poll interval in ms (default 2000).
KALSHI_MONITOR_TICKER	Optional market ticker; if unset, uses first open KXBTC15M market.

Example

npm run monitor
# [KXBTC15M-26FEB021130-30] UP   bid=0.54 ask=0.56  |  DOWN bid=0.44 ask=0.46  |  last=0.56  @ ...

In code: use getMarketPrices(ticker) or startPriceMonitor({ ticker, intervalMs, onPrices }) from ./monitor to build buy logic (e.g. buy UP when up ask < threshold, or buy DOWN when down ask < threshold).

Bitcoin up/down trading bot

The bot trades only on Bitcoin 15-minute price up/down markets (series KXBTC15M). It places one order only, on the first open market.

Bot env vars

Variable	Description
KALSHI_BOT_SIDE	yes (buy up) or no (buy down). Default: yes.
KALSHI_BOT_PRICE_CENTS	Limit price in cents (1–99). Default: 50.
KALSHI_BOT_CONTRACTS	Contracts per order. Default: 1.
KALSHI_BOT_MAX_MARKETS	Max markets to fetch when picking the first one (default 15).
KALSHI_BOT_DRY_RUN	Set to true to log only, no real orders.

Examples

# Dry run (no orders)
KALSHI_BOT_DRY_RUN=true npm run bot

# Buy YES (up) at 50¢ — one order on first open market
npm run bot

# Buy NO (down) at 45¢, 2 contracts — one order only
KALSHI_BOT_SIDE=no KALSHI_BOT_PRICE_CENTS=45 KALSHI_BOT_CONTRACTS=2 npm run bot

Docs

• Kalshi API
• TypeScript SDK quick start
• WebSockets