# MLB Kalshi vs Polymarket Odds – Same Game, Both Prices

**Use case:** 

Every MLB game listed on both Kalshi and Polymarket, one row per game: each team's price on both venues, the cheaper venue per team, the price gap, and the cost of buying the cheapest YES on both sides (arbitrage check, before fees). Thin markets are flagged. For odds screens, traders and AI agents.

## Input

```json
{
  "leagues": [
    "MLB"
  ],
  "minGap": 0,
  "onlyArbitrage": false,
  "includeUnmatched": false,
  "maxGames": 100
}
```

## Output

```json
{
  "league": {
    "label": "League",
    "format": "string"
  },
  "game": {
    "label": "Game",
    "format": "string"
  },
  "team_a": {
    "label": "Team A",
    "format": "string"
  },
  "kalshi_mid_a": {
    "label": "Kalshi mid (A)",
    "format": "number"
  },
  "polymarket_price_a": {
    "label": "Polymarket price (A)",
    "format": "number"
  },
  "gap_a": {
    "label": "Gap (A)",
    "format": "number"
  },
  "arb_cost": {
    "label": "Arb cost",
    "format": "number"
  },
  "arb_opportunity": {
    "label": "Arb opportunity",
    "format": "boolean"
  }
}
```

## About this Actor

This example demonstrates how to use [Kalshi vs Polymarket Odds – Same Game, Both Prices](https://apify.com/rowfeed/kalshi-polymarket-odds-comparison.md) with a specific input configuration. Visit the [Actor detail page](https://apify.com/rowfeed/kalshi-polymarket-odds-comparison.md) to learn more, explore other use cases, and run it yourself.


## How to integrate an Actor?

This Task's input is already configured above. Use it as-is rather than inventing a new one.

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 full API examples (JavaScript, Python, CLI, MCP, OpenAPI), see this Task's Actor page: https://apify.com/rowfeed/kalshi-polymarket-odds-comparison.md

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`).