Quick Start: Create your first order

This guide will walk you through the complete lifecycle of placing and managing orders on Kalshi.

Prerequisites

Before you begin, you’ll need:

A Kalshi account with API access configured
Python with the requests and cryptography libraries installed
Your authentication functions set up (see our authentication guide)

This guide assumes you have the authentication code from our authentication guide, including the get() function for making authenticated requests.

Step 1: Find an Open Market

First, let’s find an open market to trade on.

# Get the first open market (no auth required for public market data)
response = requests.get('https://external-api.demo.kalshi.co/trade-api/v2/markets?limit=1&status=open')
market = response.json()['markets'][0]

print(f"Selected market: {market['ticker']}")
print(f"Title: {market['title']}")

Step 2: Place a Buy Order

Now let’s place an order to buy 1 YES contract for 1 cent (limit order). We’ll use a client_order_id to deduplicate orders - this allows you to identify duplicate orders before receiving the server-generated order_id in the response.

import uuid
from urllib.parse import urlparse

def post(private_key, api_key_id, path, data, base_url=BASE_URL):
    """Make an authenticated POST request to the Kalshi API."""
    timestamp = str(int(datetime.datetime.now().timestamp() * 1000))
    # Signing requires the full URL path from root (e.g. /trade-api/v2/portfolio/events/orders)
    sign_path = urlparse(base_url + path).path
    signature = create_signature(private_key, timestamp, "POST", sign_path)

    headers = {
        'KALSHI-ACCESS-KEY': api_key_id,
        'KALSHI-ACCESS-SIGNATURE': signature,
        'KALSHI-ACCESS-TIMESTAMP': timestamp,
        'Content-Type': 'application/json'
    }

    return requests.post(base_url + path, headers=headers, json=data)

# Place a buy order for 1 YES contract at 1 cent
order_data = {
    "ticker": market['ticker'],
    "side": "bid",
    "count": "1",
    "price": "0.0100",
    "time_in_force": "good_till_canceled",
    "self_trade_prevention_type": "taker_at_cross",
    "client_order_id": str(uuid.uuid4())  # Unique ID for deduplication
}

response = post(private_key, API_KEY_ID, '/portfolio/events/orders', order_data)

if response.status_code == 201:
    order = response.json()
    print(f"Order placed successfully!")
    print(f"Order ID: {order['order_id']}")
    print(f"Client Order ID: {order_data['client_order_id']}")
    print(f"Remaining Count: {order['remaining_count']}")
else:
    print(f"Error: {response.status_code} - {response.text}")

Complete Example Script

Here’s a complete script that creates your first order:

import requests
import uuid
from urllib.parse import urlparse
# Assumes you have the authentication code from the prerequisites

# Add POST function to your existing auth code
def post(private_key, api_key_id, path, data, base_url=BASE_URL):
    """Make an authenticated POST request to the Kalshi API."""
    timestamp = str(int(datetime.datetime.now().timestamp() * 1000))
    # Signing requires the full URL path from root (e.g. /trade-api/v2/portfolio/events/orders)
    sign_path = urlparse(base_url + path).path
    signature = create_signature(private_key, timestamp, "POST", sign_path)

    headers = {
        'KALSHI-ACCESS-KEY': api_key_id,
        'KALSHI-ACCESS-SIGNATURE': signature,
        'KALSHI-ACCESS-TIMESTAMP': timestamp,
        'Content-Type': 'application/json'
    }

    return requests.post(base_url + path, headers=headers, json=data)

# Step 1: Find an open market
print("Finding an open market...")
response = requests.get('https://external-api.demo.kalshi.co/trade-api/v2/markets?limit=1&status=open')
market = response.json()['markets'][0]
print(f"Selected: {market['ticker']} - {market['title']}")

# Step 2: Place a buy order
print("\nPlacing order...")
client_order_id = str(uuid.uuid4())
order_data = {
    "ticker": market['ticker'],
    "side": "bid",
    "count": "1",
    "price": "0.0100",
    "time_in_force": "good_till_canceled",
    "self_trade_prevention_type": "taker_at_cross",
    "client_order_id": client_order_id
}

response = post(private_key, API_KEY_ID, '/portfolio/events/orders', order_data)

if response.status_code == 201:
    order = response.json()
    print(f"Order placed successfully!")
    print(f"Order ID: {order['order_id']}")
    print(f"Client Order ID: {client_order_id}")
    print(f"Remaining Count: {order['remaining_count']}")
else:
    print(f"Error: {response.status_code} - {response.text}")

Important Notes

Client Order ID

The client_order_id field is optional, but strongly recommended for order deduplication:

Generate a unique ID (like UUID4) for each order before submission when you want idempotent retries
If network issues occur, you can resubmit with the same client_order_id
The API will reject duplicate submissions with the same client_order_id, preventing accidental double orders
Store this ID locally to track orders before receiving the server’s order_id

Error Handling

Common errors and how to handle them:

401 Unauthorized: Check your API keys and signature generation
400 Bad Request: Verify your order parameters (price must be 1-99 cents)
409 Conflict: Order with this client_order_id already exists
429 Too Many Requests: You’ve hit the rate limit - slow down your requests

Next Steps

Now that you’ve created your first order, you can:

Store the returned order_id and client_order_id for local tracking
Amend your order price or quantity using POST /portfolio/events/orders/{order_id}/amend
Cancel orders using DELETE /portfolio/events/orders/{order_id}
Implement WebSocket connections for real-time updates
Build automated trading strategies

For more information, check out:

​Prerequisites

​Step 1: Find an Open Market

​Step 2: Place a Buy Order

​Complete Example Script

​Important Notes

​Client Order ID

​Error Handling

​Next Steps

Prerequisites

Step 1: Find an Open Market

Step 2: Place a Buy Order

Complete Example Script

Important Notes

Client Order ID

Error Handling

Next Steps