# Prediction Market Odds: Kalshi, Polymarket, PredictIt (`weirworks/prediction-market-odds`) Actor

Compare live odds across Kalshi, Polymarket and PredictIt. 2026 midterm races matched across venues with consensus probability and spreads, plus keyword search of any market.

- **URL**: https://apify.com/weirworks/prediction-market-odds.md
- **Developed by:** [Weirworks](https://apify.com/weirworks) (community)
- **Categories:** News, AI, Other
- **Stats:** 2 total users, 1 monthly users, 94.1% runs succeeded, 0 bookmarks
- **User rating**: No ratings yet

## Pricing

from $2.00 / 1,000 races

This Actor is paid per event. You are not charged for the Apify platform usage, but only a fixed price for specific events.

Learn more: https://docs.apify.com/actors/running/actors-in-store.md#pay-per-event

## What's an Apify Actor?

An Actor is a serverless cloud program that runs on the Apify platform. It has two run modes.
In Batch mode, an Actor accepts a well-defined JSON input, performs an action which can take anything from a few seconds to a few hours,
and optionally produces a well-defined JSON output, datasets with results, or files in key-value store.
In Standby mode, an Actor provides a web server which can be used as a website, API, or an MCP server.

Apify vocabulary and the platform model are defined once, in the agent quickstart at https://apify.com/agents.md.

## How to integrate an Actor?

If asked about integration, you help developers integrate Actors into their projects.
You adapt to their stack and deliver integrations that are safe, well-documented, and production-ready.

Do not guess an integration path. Every one of them is in the agent quickstart at https://apify.com/agents.md: the Apify MCP server, Agent Skills with the Apify CLI, the JavaScript and Python clients, the REST API, and the account-free path for an agent with no human to sign in. It also carries the rule on stating cost before the first paid run.

For examples already wired to this Actor's own input schema, see the [API](#api) section below.

Each client library has reference documentation the quickstart does not restate: [JavaScript/TypeScript](https://docs.apify.com/api/client/js/docs.md) (`npm install apify-client`) and [Python](https://docs.apify.com/api/client/python/docs.md) (`pip install apify-client`).

# README

## Prediction Market Odds: Kalshi, Polymarket, PredictIt

Live prediction-market odds from **Kalshi, Polymarket and PredictIt** in one dataset, with each **2026 US midterm race matched across venues**: one row per race showing each venue's probability, the consensus and where the venues disagree.

Built for traders looking for cross-venue spreads, journalists and newsletters tracking the midterms, campaigns and analysts, and AI agents that need current odds.

### What you get

- **Every midterm race in one run:** House and Senate control, every Senate race, every Governor race and about 430 House districts, as of October 2026.
- **Cross-venue matching:** the same race on Kalshi, Polymarket and PredictIt mapped to one race ID, e.g. `2026-SENATE-GA` or `2026-HOUSE-ME-02`.
- **Consensus and spread:** the average probability per party plus the gap between venues. Filter by `minSpread` to find disagreements, e.g. Kalshi 80% against PredictIt 50%.
- **Candidates:** candidate names where the venues list them.
- **Search mode:** search any topic (bitcoin, Fed rates, Ukraine, impeachment, sports) across venues, most-traded first. Manifold is included as a play-money option.
- **Fast and cheap:** official public APIs, no login, no proxy. A full midterm run takes about 25 seconds.
- **Strictly neutral:** every party and race is covered the same way.

### Example: midterms mode

```json
{ "mode": "midterms", "offices": ["SENATE", "HOUSE-CONTROL", "SENATE-CONTROL"], "minVenues": 2 }
```

Output row:

```json
{
  "type": "race",
  "raceId": "2026-SENATE-TX",
  "race": "Texas Senate 2026",
  "office": "SENATE",
  "state": "TX",
  "democratProbability": {"kalshi": 0.635, "polymarket": 0.605, "predictit": 0.61},
  "democratConsensus": 0.6167,
  "democratSpread": 0.03,
  "democratCandidates": ["James Talarico"],
  "republicanProbability": {"kalshi": 0.375, "polymarket": 0.385, "predictit": 0.405},
  "republicanConsensus": 0.3883,
  "favorite": "D",
  "venues": ["kalshi", "polymarket", "predictit"],
  "maxSpread": 0.03,
  "urls": {"kalshi": "https://kalshi.com/markets/...", "polymarket": "https://polymarket.com/event/...", "predictit": "https://www.predictit.org/markets/detail/..."}
}
```

Probabilities are the mid-point of bid and ask when the book is tight, otherwise the last traded price, on a 0–1 scale.

### Example: search mode

```json
{ "mode": "search", "searchQuery": "Fed rate", "venues": ["kalshi", "polymarket", "manifold"] }
```

Each market row has `venue`, `question`, `outcome`, `probability`, `bid`, `ask`, `lastPrice`, `volume`, `closeTime` and `url`.

### Pricing

- **$2 per 1,000 race rows** (a full midterm board of about 500 races costs about $1)
- **$0.80 per 1,000 market rows**

No start fee. You can set a maximum cost per run.

### Tips

- Schedule it hourly or daily to build a time series of odds.
- `minVenues: 3` gives the races where all three venues have markets, which is best for comparing.
- Kalshi lists far more House districts than the other venues, so those rows often show one venue only.

### Disclaimer

This is market data for information and research, not betting or financial advice. Prices change constantly; check them on the venue before acting. Use each venue's data in line with its terms.

Questions: open an issue or email **hello@weirworks.com**.

*Independent tool by weirworks. Not affiliated with Kalshi, Polymarket, PredictIt or Manifold.*

# Actor input Schema

## `mode` (type: `string`):

Midterms mode returns one row per race (House/Senate control, every Senate, Governor and House race) with each venue's probability, the consensus and the spread. Search mode returns individual markets for any topic.

## `venues` (type: `array`):

Which venues to read.

## `offices` (type: `array`):

Leave empty for all.

## `states` (type: `array`):

Two-letter state codes, e.g. <code>GA</code>, <code>TX</code>. Leave empty for all.

## `minVenues` (type: `integer`):

Set to 2 or 3 to return only races priced on several venues (best for comparing and arbitrage).

## `minSpread` (type: `number`):

Only races where venues disagree by at least this much (0.05 = 5 percentage points).

## `includeMarkets` (type: `boolean`):

Adds one row per venue market/outcome (bid, ask, last price, volume, close time, link).

## `searchQuery` (type: `string`):

Search mode: any topic, e.g. <code>bitcoin</code>, <code>Fed rate</code>, <code>Ukraine ceasefire</code>, <code>impeachment</code>.

## `maxMarkets` (type: `integer`):

Most-traded markets first.

## `proxyConfiguration` (type: `object`):

Not needed: these are public market-data APIs.

## Actor input object example

```json
{
  "mode": "midterms",
  "venues": [
    "kalshi",
    "polymarket",
    "predictit"
  ],
  "minVenues": 1,
  "minSpread": 0,
  "includeMarkets": false,
  "maxMarkets": 200,
  "proxyConfiguration": {
    "useApifyProxy": false
  }
}
```

# Actor output Schema

## `results` (type: `string`):

The dataset rows.

# API

You can run this Actor programmatically using our API. Below are code examples in JavaScript, Python, and CLI, as well as the OpenAPI specification and MCP server setup.

## JavaScript example

```javascript
import { ApifyClient } from 'apify-client';

// Initialize the ApifyClient with your Apify API token
// Replace the '<YOUR_API_TOKEN>' with your token
const client = new ApifyClient({
    token: '<YOUR_API_TOKEN>',
});

// Prepare Actor input
const input = {
    "proxyConfiguration": {
        "useApifyProxy": false
    }
};

// Run the Actor and wait for it to finish
const run = await client.actor("weirworks/prediction-market-odds").call(input);

// Fetch and print Actor results from the run's dataset (if any)
console.log('Results from dataset');
console.log(`💾 Check your data here: https://console.apify.com/storage/datasets/${run.defaultDatasetId}`);
const { items } = await client.dataset(run.defaultDatasetId).listItems();
items.forEach((item) => {
    console.dir(item);
});

// 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/js/docs

```

## Python example

```python
from apify_client import ApifyClient

# Initialize the ApifyClient with your Apify API token
# Replace '<YOUR_API_TOKEN>' with your token.
client = ApifyClient("<YOUR_API_TOKEN>")

# Prepare the Actor input
run_input = { "proxyConfiguration": { "useApifyProxy": False } }

# Run the Actor and wait for it to finish
run = client.actor("weirworks/prediction-market-odds").call(run_input=run_input)

# Fetch and print Actor results from the run's dataset (if there are any)
print(f"💾 Check your data here: https://console.apify.com/storage/datasets/{run.default_dataset_id}")
for item in client.dataset(run.default_dataset_id).iterate_items():
    print(item)

# 📚 Want to learn more 📖? Go to → https://docs.apify.com/api/client/python/docs/quick-start

```

## CLI example

```bash
echo '{
  "proxyConfiguration": {
    "useApifyProxy": false
  }
}' |
apify call weirworks/prediction-market-odds --silent --output-dataset

```

## MCP server setup

```json
{
    "mcpServers": {
        "apify": {
            "type": "http",
            "url": "https://mcp.apify.com/?tools=fetch-actor-details,weirworks/prediction-market-odds"
        }
    }
}
```

The hosted server signs you in with OAuth on first connect, so no API token belongs in this config. Clients without OAuth support can send an `Authorization: Bearer <APIFY_API_TOKEN>` header instead, using a token from API & Integrations in Apify Console (https://console.apify.com/settings/integrations).

## OpenAPI specification

Download the OpenAPI definition: https://api.apify.com/v2/actors/V8kMBKJYvzTu5lNdi/builds/oOwqL1IVyizv1pt9U/openapi.json