Developer Guide

How to Get Kalshi Market Data via API

Kalshi is a regulated US prediction market. Here's how to pull its implied odds programmatically and line them up against sportsbooks, with code examples and a free tier.

ByMike·Founder, SharpAPI

You can get Kalshi market data via API by using an odds aggregation service like SharpAPI. Sign up for a free account, generate an API key, and make a single REST call to get Kalshi implied probabilities normalized alongside 44+ sportsbooks and Polymarket. Kalshi's own trading API exists, but it is built for trading on Kalshi, one venue in its own schema. Most developers use an aggregator so Kalshi lines sit next to sportsbook odds in the same response, ready to compare.

Why Kalshi Market Data Matters

Kalshi is a CFTC-regulated prediction market where every contract price is a live implied probability. A contract that trades at 62 cents means the market prices that outcome at roughly 62 percent. Because Kalshi is an exchange driven by traders taking both sides, its prices are a second independent read on an event, separate from how sportsbooks set their lines.

For a developer building betting or trading tools, that independent read is the value. When Kalshi's implied probability diverges from the sportsbook consensus, that gap is a signal, and sometimes an arbitrage or positive expected value opportunity. To find it, you need Kalshi prices in the same format and the same call as your sportsbook data.

Regulated

CFTC-regulated US exchange, contracts settle on real outcomes

Implied %

Contract price is a direct probability, no vig to remove

Independent

Exchange-driven prices, a separate read from sportsbook lines

Your Options for Getting Kalshi Data

MethodRequirementsDataBest For
Kalshi Trading APIKalshi account, API key auth, per-contract requestsKalshi only, own schemaTrading on Kalshi directly
SharpAPIFree sign-up, no Kalshi account neededKalshi + Polymarket + sportsbooks, one schemaBuilding odds, arbitrage, and EV tools
Web scrapingProxy infrastructure, anti-bot bypass, ongoing maintenanceKalshi only (fragile)Not recommended

Recommendation: If your goal is to trade on Kalshi, use Kalshi's own API. If your goal is to compare Kalshi against sportsbooks and other prediction markets, an aggregation API is the fastest path. You skip the per-venue integrations, the schema reconciliation, and the event-mapping work.

Step-by-Step: Get Kalshi Data in 5 Minutes

1

Create a free SharpAPI account

Sign up at sharpapi.io, no credit card required. You get 12 requests/minute immediately.

2

Generate an API key

Go to your API Keys dashboard and create a new key. Copy it for use in the Authorization header.

3

Install the SDK (optional)

npm install @sharp-api/sdk or pip install sharpapi. Or use plain HTTP with any language.

4

Request Kalshi implied odds

Pass sportsbook=kalshi to filter for Kalshi, or list it with sportsbooks to get everything in one response.

Code Examples

TypeScript (SDK)

const res = await fetch(
  'https://api.sharpapi.io/api/v1/odds?sport=basketball&sportsbook=kalshi,pinnacle,draftkings&markets=h2h',
  { headers: { 'X-API-Key': process.env.SHARPAPI_KEY } },
)
const { data } = await res.json()

// One flat array. Each row carries its own sportsbook and implied probability.
for (const row of data) {
  console.log(row.selection, row.sportsbook, row.odds_probability)
}

Python (SDK)

import requests

res = requests.get(
    "https://api.sharpapi.io/api/v1/odds",
    params={"sport": "basketball", "sportsbook": "kalshi,pinnacle,draftkings", "markets": "h2h"},
    headers={"X-API-Key": "YOUR_API_KEY"},
)

# One flat array. Each row carries its own sportsbook and implied probability.
for row in res.json()["data"]:
    print(row["selection"], row["sportsbook"], row["odds_probability"])

cURL (any language)

curl -X GET "https://api.sharpapi.io/api/v1/odds?sport=basketball&sportsbook=kalshi,pinnacle,draftkings&markets=h2h" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Accept: application/json"

Kalshi vs Sportsbook Consensus

The reason to normalize Kalshi alongside sportsbooks is to spot where they disagree. A Kalshi contract already states an implied probability directly. Convert a sportsbook line to its no-vig fair probability and you can compare the two on the same scale.

Worked Example: Prediction Market vs Sportsbook

Event: Team A to win

Kalshi contract:        58c  -> implied 58.0%
Sportsbook fair odds:   -122 -> no-vig  55.0%

Gap = 58.0% - 55.0% = 3.0%

The market and the books disagree by 3 points. Depending on
direction and price, that can be a +EV bet on one side or a
cross-venue arbitrage. SharpAPI flags the gap automatically.

SharpAPI's +EV endpoint and arbitrage endpoint compute these gaps across Kalshi, Polymarket, and every covered sportsbook in real time, and can stream them over SSE.

Frequently Asked Questions

Does Kalshi have an API?+
Yes. Kalshi offers an official trading API with REST and WebSocket access. It is built for trading on Kalshi: it handles authentication, order books, positions, and per-contract data on the Kalshi exchange. What it does not do is give you Kalshi implied probabilities normalized next to sportsbook lines, which is what most odds and analytics tools actually need. SharpAPI fills that gap.
What is the difference between the Kalshi API and SharpAPI?+
The Kalshi API returns Kalshi contracts in Kalshi's own schema, one venue in isolation. SharpAPI normalizes Kalshi implied probabilities into the same schema as 44+ sportsbooks and Polymarket, so a single call returns Kalshi next to DraftKings, Pinnacle, and the rest. You integrate once and compare across every venue instead of stitching separate APIs together.
How do I get Kalshi odds alongside sportsbooks?+
Sign up for a free SharpAPI account, generate an API key, and pass sportsbook=kalshi (with any sportsbooks you want) to a single odds endpoint. You get Kalshi implied probabilities and sportsbook lines for the same event in one response, no separate Kalshi integration required.
How does SharpAPI get Kalshi data?+
SharpAPI collects Kalshi market prices through proprietary adapters and maps each Kalshi event contract to the matching sporting event. Prices are normalized into implied probabilities with consistent field names, so Kalshi lines format the same way as every sportsbook in the response.
Can I compare Kalshi to Polymarket and traditional sportsbooks?+
Yes. SharpAPI returns Kalshi, Polymarket, and 44+ sportsbooks in a single response. Compare implied probabilities across prediction markets and books without managing multiple data sources or reconciling different schemas.
What events does Kalshi cover?+
Kalshi is a CFTC-regulated US prediction market where contracts settle on real-world outcomes, including sports, politics, and economics. SharpAPI normalizes the sports-overlapping Kalshi markets alongside traditional sportsbook lines, giving you one unified view of market consensus.
How fast are Kalshi updates on SharpAPI?+
SharpAPI updates Kalshi contract prices in near real time. On paid plans with SSE streaming, you receive Kalshi price changes as they happen, typically within seconds of the market moving, in the same stream as sportsbook line changes.

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