Kalshi on Molecule: Discover Markets and Submit Orders

Kalshi is a prediction market exchange offering event contracts. Molecule connects to Kalshi as a live execution venue, enabling you to discover Kalshi instruments, retrieve market data, and submit orders without building a separate Kalshi integration. The same authentication, signing, and order-management flow you use across the Molecule API applies here.

Discovering Kalshi Markets

Use client.markets.search() with venue="Kalshi" to retrieve available Kalshi instruments. Filter by status or keyword to narrow results.

from molecule import Molecule

client = Molecule(
    base_url="https://api.molecule.markets",
    key_id="your-key-id",
    private_key="your-private-key",
)

# Search all active Kalshi markets
markets = client.markets.search(venue="Kalshi", status="active")
for market in markets.get("results", []):
    print(market["instrument_id"], market["ticker"], market["outcome"])

Use client.markets.match() to look up a specific Kalshi market by ticker or slug when you already know its identifier:

# Match by ticker
instrument = client.markets.match(ticker="KXBTC-23DEC31-T30000")
print(instrument)

Kalshi markets trade binary YES/NO contracts. Each market produces a YES instrument and a NO instrument, each with its own instrument_id. Both instruments share a common generic_asset_id that you can use for cross-venue routing. You can inspect the live order book for a specific Kalshi instrument or retrieve the aggregated view across all venues:

# Single-instrument order book
book = client.markets.orderbook(instrument_id=12345)
print(book)

# Aggregated order book across all venues for a given asset
agg_book = client.markets.generic_asset_orderbook(generic_asset_id=42)
print(agg_book)

Submitting Orders to Kalshi

DIRECT routing to Kalshi

Use routing.mode = "DIRECT" with a Kalshi instrument_id to route an order to a specific Kalshi contract. Retrieve the instrument_id from a prior search() or match() call.

# Place a limit buy order for YES on a specific Kalshi instrument
order = client.orders.create(
    subaccount_id="sub_abc123",
    instrument_id=12345,          # Kalshi YES instrument
    side="BUY",
    outcome="YES",
    type="LIMIT",
    tif="GTC",
    price="0.45",
    qty="150",
    routing={"mode": "DIRECT"},
    client_order_id="kal-direct-001",
)
print(order)

Cross-venue routing with BEST_PRICE

Use routing.mode = "BEST_PRICE" with a generic_asset_id to let Molecule select whichever connected venue — including Kalshi — currently offers the best available price for the asset.

# Route to the venue with the best available price
order = client.orders.create(
    subaccount_id="sub_abc123",
    generic_asset_id=42,          # cross-venue asset identifier
    side="BUY",
    outcome="YES",
    type="LIMIT",
    tif="GTC",
    price="0.45",
    qty="150",
    routing={"mode": "BEST_PRICE"},
    client_order_id="kal-bestprice-001",
)
print(order)

To distribute a larger order across Kalshi and other venues simultaneously, use SPLIT:

# Split the order across all venues with available liquidity
order = client.orders.create(
    subaccount_id="sub_abc123",
    generic_asset_id=42,
    side="BUY",
    outcome="YES",
    type="LIMIT",
    tif="GTC",
    price="0.45",
    qty="400",
    routing={"mode": "SPLIT"},
    client_order_id="kal-split-001",
)
print(order)

Notes

Kalshi instruments require a venue-specific instrument_id for DIRECT routing. Retrieve this from client.markets.search(venue="Kalshi") or client.markets.match().
To route across Kalshi and other connected venues without targeting a specific instrument, use generic_asset_id with BEST_PRICE or SPLIT routing mode.
Each binary Kalshi market produces two separate instruments (YES and NO). Confirm the outcome field on the instrument before submitting a DIRECT order to ensure you are trading the intended side.
The client_order_id field acts as the idempotency key for simple orders. Resubmitting the same client_order_id with an identical payload is safe; resubmitting with a different payload returns a ConflictError.

Use the Demo venue to validate your integration before sending orders to live Kalshi. Demo provides the same API surface without live execution risk. Switch to Kalshi by changing venue="Kalshi" in your market queries and using a Kalshi instrument_id or a generic_asset_id that maps to Kalshi instruments.

Overview

Authentication

Guides

Venues

Security

Kalshi on Molecule: Discover Markets and Submit Orders

Discovering Kalshi Markets

Submitting Orders to Kalshi

DIRECT routing to Kalshi

Cross-venue routing with BEST_PRICE

Notes

​Discovering Kalshi Markets

​Submitting Orders to Kalshi

​DIRECT routing to Kalshi

​Cross-venue routing with BEST_PRICE

​Notes

Discovering Kalshi Markets

Submitting Orders to Kalshi

DIRECT routing to Kalshi

Cross-venue routing with BEST_PRICE

Notes