# Kalshi API

> Kalshi returns prediction markets, outcomes, and trading volumes as a workflow and API.

Kalshi finds prediction events about a topic, ranked by total contracts traded. Search markets takes a required topic and can include closed or settled events.

- Page: https://fous.com/tools/kalshi
- Handle: `@kalshi`
- Category: [Finance](https://fous.com/tools/category/finance)
- Source website: https://kalshi.com
- Last verified: Sep 29, 2026

## Methods

### Search markets

Operation `search_markets`, version 1. 1 credit per completed call. Failed calls without a completed billing receipt are free; completed work can remain charged if delivery is interrupted.

Find Kalshi prediction events about a topic, ranked by total contracts traded, with Yes prices, outcome volumes and status. Settled chances show the resolved result; closed outcomes have no live buy or sell prices. Older closed markets may lack 24-hour volume; very broad searches cover up to 1,000 matches.

**Input**

| Field | Type | Required | Example | Description |
|---|---|---|---|---|
| `topic` | string | yes | `"Fed rate decision"` | Words describing the event, for example Fed rate decision. |
| `max_results` | integer | no | `3` | Maximum number of events, for example 5. |
| `include_closed` | boolean | no | `true` | Include closed and settled events, for example true. |

**Input schema**

```json
{
  "type": "object",
  "required": [
    "topic"
  ],
  "properties": {
    "topic": {
      "type": "string",
      "minLength": 1,
      "description": "Words describing the event, for example Fed rate decision.",
      "examples": [
        "Fed rate decision",
        "Super Bowl",
        "nonexistentzzzzzzzzzz"
      ]
    },
    "max_results": {
      "type": "integer",
      "default": 5,
      "maximum": 20,
      "minimum": 1,
      "description": "Maximum number of events, for example 5.",
      "x-fous-developer": true,
      "examples": [
        3
      ]
    },
    "include_closed": {
      "type": "boolean",
      "default": false,
      "description": "Include closed and settled events, for example true.",
      "examples": [
        true
      ]
    }
  },
  "additionalProperties": false,
  "examples": [
    {
      "topic": "Fed rate decision"
    },
    {
      "topic": "Super Bowl",
      "max_results": 3,
      "include_closed": true
    },
    {
      "topic": "nonexistentzzzzzzzzzz"
    }
  ]
}
```

**Output**

| Field | Type | Example | Description |
|---|---|---|---|
| `events` | array |  | Matching Kalshi events sorted by total trading volume, highest first. |
| `events[].link` | string | `"https://kalshi.com/markets/kxratecutcount/number-of-rate-cuts/kxratecutcount-26dec31"` |  |
| `events[].title` | string | `"Number of rate cuts in 2026?"` |  |
| `events[].volume` | number or null | `10041560` |  |
| `events[].category` | string or null | `"Economics"` |  |
| `events[].outcomes` | array |  |  |
| `events[].close_time` | string or null | `"2027-01-01T04:59:00Z"` |  |
| `events[].event_ticker` | string | `"KXRATECUTCOUNT-26DEC31"` |  |

**Example input**

```json
{
  "topic": "Fed rate decision"
}
```

**Example output**

```json
{
  "events": [
    {
      "link": "https://kalshi.com/markets/kxratecutcount/number-of-rate-cuts/kxratecutcount-26dec31",
      "title": "Number of rate cuts in 2026?",
      "volume": 10041560,
      "category": "Economics",
      "outcomes": [
        {
          "name": "Exactly 0 cuts",
          "status": "open",
          "volume": 2616604.51,
          "volume_24h": 10560.05,
          "market_ticker": "KXRATECUTCOUNT-26DEC31-T0",
          "chance_percent": 94.8,
          "yes_buy_price_usd": 0.948,
          "yes_sell_price_usd": 0.947
        },
        {
          "name": "Exactly 1 cut",
          "status": "open",
          "volume": 1140919.67,
          "volume_24h": 8777.09,
          "market_ticker": "KXRATECUTCOUNT-26DEC31-T1",
          "chance_percent": 3,
          "yes_buy_price_usd": 0.03,
          "yes_sell_price_usd": 0.022
        }
      ],
      "close_time": "2027-01-01T04:59:00Z",
      "event_ticker": "KXRATECUTCOUNT-26DEC31"
    },
    {
      "link": "https://kalshi.com/markets/kxfeddecision/fed-meeting/kxfeddecision-26oct",
      "title": "Fed decision in Oct 2026?",
      "volume": 3762301,
      "category": "Economics",
      "outcomes": [
        {
          "name": "Hike 25bps",
          "status": "open",
          "volume": 1074767.53,
          "volume_24h": 43993.15,
          "market_ticker": "KXFEDDECISION-26OCT-H25",
          "chance_percent": 70,
          "yes_buy_price_usd": 0.7,
          "yes_sell_price_usd": 0.69
        },
        {
          "name": "Fed maintains rate",
          "status": "open",
          "volume": 1367286.18,
          "volume_24h": 106259.29,
          "market_ticker": "KXFEDDECISION-26OCT-H0",
          "chance_percent": 30,
          "yes_buy_price_usd": 0.3,
          "yes_sell_price_usd": 0.29
        }
      ],
      "close_time": "2026-10-28T17:59:00Z",
      "event_ticker": "KXFEDDECISION-26OCT"
    }
  ]
}
```

## Quick start

Replace `YOUR_API_KEY` with a Fous API key. To create one, open Developers at the bottom of Fous Studio, turn on Developer mode, then go to API keys (https://app.fous.com/keys). Change the values in `input` to run the same tool on new data.

```bash
curl 'https://api.fous.com/v1/query' \
  --fail-with-body --silent --show-error --max-time 180 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "api": "@kalshi",
  "visibility": "public",
  "operation": "search_markets",
  "version": 1,
  "input": {
    "topic": "Fed rate decision"
  },
  "response": {
    "format": "json"
  }
}'
```

```python
# Save as fous.py and run with python3 fous.py. No packages needed.
import json
import urllib.error
import urllib.request

api_key = "YOUR_API_KEY"

body = json.loads("{\n  \"api\": \"@kalshi\",\n  \"visibility\": \"public\",\n  \"operation\": \"search_markets\",\n  \"version\": 1,\n  \"input\": {\n    \"topic\": \"Fed rate decision\"\n  },\n  \"response\": {\n    \"format\": \"json\"\n  }\n}")
request = urllib.request.Request(
    "https://api.fous.com/v1/query",
    data=json.dumps(body).encode("utf-8"),
    headers={
        "Authorization": f"Bearer {api_key}",
        "Content-Type": "application/json",
    },
    method="POST",
)
try:
    with urllib.request.urlopen(request, timeout=180) as response:
        result = json.load(response)
except urllib.error.HTTPError as error:
    raise RuntimeError(f"HTTP {error.code}: {error.read().decode('utf-8', errors='replace')}") from error
if result.get("success") is False:
    raise RuntimeError(result.get("error", {}).get("message", "Request failed"))
print(json.dumps(result["data"]["output"], indent=2))
```

```typescript
// Save as fous.mts and run with npx tsx fous.mts.
const apiKey = "YOUR_API_KEY";

const response = await fetch("https://api.fous.com/v1/query", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${apiKey}`,
    "Content-Type": "application/json",
  },
  signal: AbortSignal.timeout(180_000),
  body: JSON.stringify({
  "api": "@kalshi",
  "visibility": "public",
  "operation": "search_markets",
  "version": 1,
  "input": {
    "topic": "Fed rate decision"
  },
  "response": {
    "format": "json"
  }
}),
});
type ApiResult = { success: boolean; data?: { output: unknown }; error?: { message: string } };
const result: ApiResult = await response.json();
if (!response.ok || result.success === false) {
  throw new Error(result.error?.message ?? `HTTP ${response.status}`);
}
if (!result.data) throw new Error("Missing API response data");
console.log(result.data.output);
```

## Use from an AI assistant

Connect this tool to Claude Code, Claude Desktop, Cursor, VS Code, Codex and any MCP client as its own MCP server. Each method is a typed tool whose arguments are the method’s input.

- Server URL: `https://api.fous.com/mcp/tools/kalshi`
- Authorization: `Authorization: Bearer <Fous API key>`

**Tools**

- `search_markets`: Search markets. 1 credit per completed call. Failed calls without a completed billing receipt are free; completed work can remain charged if delivery is interrupted.
- `fous_get_run`: the result of a run that was still going, by its `request_id`. Free.

Claude Code:

```bash
claude mcp add --scope user --transport http fous-kalshi https://api.fous.com/mcp/tools/kalshi --header "Authorization: Bearer ${FOUS_API_KEY:?Set FOUS_API_KEY to your Fous API key}"
```

To give the assistant every tool, connect `https://api.fous.com/mcp`: it finds one with `fous_search_tools` and runs it with `fous_run_tool`. Setup for other clients: https://fous.com/llms-full.txt.

## Use cases

- Compare trading volume across prediction events
- Track Yes prices and outcome volumes
- Review resolved results for settled events

## FAQ

### Can I run it with my own inputs?

Yes. Change the inputs in Studio and press Run, or send new inputs from your code, or ask a connected AI assistant.

### Can I call this Kalshi tool as an API?

Yes. Send a POST request to /v1/query with your Fous API key and the inputs, and get JSON back.

### How much does it cost?

Each completed run costs 1 credit. Failed runs without a completed receipt are free; completed work can remain charged if delivery is interrupted. With pay as you go, a credit costs 1¢. Monthly plans cost less per credit.

### Do I need a Kalshi account?

No. You only need a Fous account.

### How current is the data?

Fous gets the data from kalshi.com when you run it. Some results are reused for up to 24 hours, and results that use your account or key are never reused. It was last verified on Sep 29, 2026.

### Which prediction events match a topic?

Search markets finds events matching a topic and returns their titles, categories, outcomes, and status.

### Which events have the highest trading volume?

Search markets sorts matching events by total trading volume, highest first.

### What result did a settled event resolve to?

Search markets returns settled chances showing the resolved result.

## Related

- [Polymarket API](https://fous.com/tools/polymarket.md): Polymarket shows searchable markets with search-time odds and sometimes-unavailable 24-hour volume, ranks open markets by trading, and tracks chances over time, sometimes without recent points.
- [Investing.com API](https://fous.com/tools/investing-com.md): Investing.com provides financial markets data and news, economic releases up to 31 days, and current commodity prices and government bond yields, which may be delayed or indicative.
- [Nasdaq API](https://fous.com/tools/nasdaq.md): Nasdaq provides market activity, scheduled earnings by date with fiscal quarter-end month, monthly US IPO listings, and dated ex-dividend entries; dividend histories cover Nasdaq-listed stocks only.
- [TradingView API](https://fous.com/tools/tradingview.md): TradingView provides charts, markets, and technical analysis, with changing buy, sell, or neutral signals and stock screening; quotes may be delayed.
- [Kraken API](https://fous.com/tools/kraken.md): Live cryptocurrency market prices and trading statistics from Kraken.
- [Kitco API](https://fous.com/tools/kitco.md): Precious metals spot prices and market coverage.
- [StubHub API](https://fous.com/tools/stubhub.md): Find resale tickets and fee-inclusive prices for live events.
- [The Wall Street Journal API](https://fous.com/tools/the-wall-street-journal.md): The Wall Street Journal provides news-section headlines and searchable public article headlines and summaries, with available story details and publication dates for search filtering.
- [All Finance tools](https://fous.com/tools/category/finance)