SimpleFunctions Developer Manual

Use the Real-Time Data API when you need raw market data for a terminal, dashboard, bot, or trading agent. This surface is separate from simplefunctions.dev/api/public/*. The public API is for analytical objects and agent workflows. The data API is for fast market data. Last verified: 2026-04-30.

Base URLs

REST:

https://data.simplefunctions.dev/v1

Current public WebSocket:

wss://app.simplefunctions.dev/ws

Do not use wss://data.simplefunctions.dev/v1/ws yet. It is the intended canonical data-domain WebSocket name, but current routing can return 426 Upgrade Required. Use wss://app.simplefunctions.dev/ws until the WS route is moved off Vercel or a direct WS CNAME is configured.

Data conventions

Field	Convention
Prices	Probabilities in `[0, 1]`, not cents.
`generated_at`	Unix seconds.
`closeTime`	Unix seconds.
`ts`	Unix milliseconds.
Compression	Large REST responses are gzip-compressed by the origin.

REST endpoints

Endpoint	Use	Cache
`GET /v1/heartbeat`	Health/status payload.	`max-age=10`
`GET /v1/markets?q=&venue=`	Top tracked markets or registry search.	`max-age=3`
`GET /v1/markets/featured?n=50`	Heat-ranked featured markets.	`max-age=3`
`GET /v1/markets/{ticker}`	One market snapshot.	`max-age=2`
`GET /v1/search?q=&limit=&venue=&strict=`	Autocomplete-grade ticker/title search.	`max-age=5`
`GET /v1/snapshot`	Compact full active-universe price snapshot.	`max-age=2`
`GET /v1/movers?window=&n=&minVol=&dir=`	Top price movers over a recent window.	`max-age=5`
`GET /v1/orderbook/{ticker}`	Top-of-book/depth snapshot.	`max-age=1`
`GET /v1/candles/{ticker}?tf=1h&limit=500`	OHLCV candles.	`max-age=5` or `15` for `1d`
`GET /v1/trades/{ticker}?limit=50`	Recent trade prints.	`max-age=1`

Heartbeat

curl "https://data.simplefunctions.dev/v1/heartbeat"

{
  "markets_tracked": 9333,
  "ws_clients": 3,
  "top_volume_market": "KXPRESNOMD-28-GN",
  "uptime_s": 12345,
  "generated_at": 1777553300
}

Markets

curl "https://data.simplefunctions.dev/v1/markets"
curl "https://data.simplefunctions.dev/v1/markets?q=newsom&venue=kalshi"
curl "https://data.simplefunctions.dev/v1/markets/featured?n=50"
curl "https://data.simplefunctions.dev/v1/markets/KXPRESNOMD-28-GN"

Market object:

{
  "ticker": "KXPRESNOMD-28-GN",
  "venue": "kalshi",
  "title": "Will Gavin Newsom be the Democratic Presidential nominee in 2028?",
  "lastPrice": 0.26,
  "volume24h": 12345,
  "closeTime": 1853884800,
  "bestBid": 0.25,
  "bestAsk": 0.27,
  "heat": 81.4
}

Search

curl "https://data.simplefunctions.dev/v1/search?q=newsom&limit=10"
curl "https://data.simplefunctions.dev/v1/search?q=rate%20cut&venue=kalshi&strict=0"

Parameters:

Parameter	Values	Use
`q`	string	Required query.
`limit`	`1` to `50`	Result cap. Default `10`.
`venue`	`kalshi`, `polymarket`	Optional venue filter.
`strict`	`1`, `0`	`strict=0` enables looser substring matching for short tokens.

Response:

{
  "query": "newsom",
  "results": [
    {
      "ticker": "KXPRESNOMD-28-GN",
      "venue": "kalshi",
      "title": "Will Gavin Newsom be the Democratic Presidential nominee in 2028?",
      "lastPrice": 0.26,
      "volume24h": 12345,
      "score": 400
    }
  ]
}

Raw snapshot

curl "https://data.simplefunctions.dev/v1/snapshot"

Use this for bot cold-start. It intentionally omits title, close time, and heat to keep the payload small. Markets pinned outside [0.01, 0.99] are excluded.

{
  "generated_at": 1777553300,
  "count": 9000,
  "markets": [
    {
      "ticker": "KXPRESNOMD-28-GN",
      "venue": "kalshi",
      "last": 0.26,
      "bid": 0.25,
      "ask": 0.27,
      "vol24h": 12345
    }
  ]
}

Movers

curl "https://data.simplefunctions.dev/v1/movers?window=1h&n=50&minVol=1000&dir=both"

Parameters:

Parameter	Values	Use
`window`	`1m`, `5m`, `15m`, `1h`, `4h`, `24h`, `1d`	Move window. Default `1h`.
`n`	`10` to `200`	Result cap. Default `50`.
`minVol`	number	24h volume floor. Default `1000`.
`dir`	`up`, `down`, `both`	Direction filter. Default `both`.

/v1/movers is powered by in-memory tick/trade samples. After deploy or reconnect, short windows can return count: 0 until samples accumulate.

Orderbook, candles, trades

curl "https://data.simplefunctions.dev/v1/orderbook/KXPRESNOMD-28-GN"
curl "https://data.simplefunctions.dev/v1/candles/KXPRESNOMD-28-GN?tf=1h&limit=500"
curl "https://data.simplefunctions.dev/v1/trades/KXPRESNOMD-28-GN?limit=50"

Orderbook:

{
  "ticker": "KXPRESNOMD-28-GN",
  "bids": [[0.25, 1200]],
  "asks": [[0.27, 700]],
  "ts": 1777553300123
}

Candles:

{
  "ticker": "KXPRESNOMD-28-GN",
  "timeframe": "1h",
  "candles": [
    { "t": 1777550400000, "o": 0.25, "h": 0.27, "l": 0.24, "c": 0.26, "v": 900 }
  ]
}

Trades:

{
  "ticker": "KXPRESNOMD-28-GN",
  "trades": [
    {
      "ticker": "KXPRESNOMD-28-GN",
      "venue": "kalshi",
      "price": 0.26,
      "size": 10,
      "side": "buy",
      "ts": 1777553300123
    }
  ]
}

WebSocket

const ws = new WebSocket('wss://app.simplefunctions.dev/ws')

ws.addEventListener('open', () => {
  ws.send(JSON.stringify({
    action: 'subscribe',
    topics: [
      'featured',
      'ticker:KXPRESNOMD-28-GN',
      'orderbook:KXPRESNOMD-28-GN',
      'trade:KXPRESNOMD-28-GN',
      'candle:KXPRESNOMD-28-GN:1m'
    ],
  }))
})

ws.addEventListener('message', (event) => {
  const frame = JSON.parse(event.data)
  console.log(frame.type, frame)
})

Subscribe:

{
  "action": "subscribe",
  "topics": [
    "featured",
    "ticker:KXPRESNOMD-28-GN",
    "orderbook:KXPRESNOMD-28-GN",
    "trade:KXPRESNOMD-28-GN",
    "candle:KXPRESNOMD-28-GN:1m"
  ]
}

Unsubscribe:

{
  "action": "unsubscribe",
  "topics": ["ticker:KXPRESNOMD-28-GN"]
}

Legacy single-topic subscribe is also accepted:

{ "action": "subscribe", "ticker": "KXPRESNOMD-28-GN" }

WebSocket topics

Topic	Frame type	Use
`featured`	`featured`	Top-50 heat-ranked list.
`ticker:{ticker}`	`ticker_info`	Latest price/quote metadata.
`orderbook:{ticker}`	`orderbook`	Sorted book snapshot.
`trade:{ticker}`	`trade`	Trade prints from venue WS.
`candle:{ticker}:{tf}`	`candle`	Candle updates for one timeframe.
`{ticker}`	mixed	Legacy topic with ticker/orderbook/trade/candle fan-out.

When subscribing to a ticker topic, the server may send initial cached ticker_info and orderbook frames if available.

Frame shapes

featured:

{
  "type": "featured",
  "markets": [],
  "generated_at": 1777553300
}

ticker_info:

{
  "type": "ticker_info",
  "ticker": "KXPRESNOMD-28-GN",
  "venue": "kalshi",
  "title": "Will Gavin Newsom be the Democratic Presidential nominee in 2028?",
  "last": 0.26,
  "bid": 0.25,
  "ask": 0.27,
  "volume24h": 12345,
  "closeTime": 1853884800
}

orderbook, trade, and candle use the same shapes as the REST examples above, with a top-level type.

Operational notes

Public REST callers use https://data.simplefunctions.dev/v1; the edge proxy injects the internal origin token.
Direct origin routes at https://app.simplefunctions.dev/api/data/v1/* are edge-token gated and return 403 without the internal token.
Anonymous WebSocket connections are capped per IP.
The server pings WebSocket clients every 30 seconds and closes stale connections after a failed pong.
Kalshi and Polymarket are normalized into one ticker namespace, but not all fields are available from both venues.

CLI

HTTP API

Tools and events

Data

Configuration

Real-Time Data API

Base URLs

Data conventions

REST endpoints

Heartbeat

Markets

Search

Raw snapshot

Movers

Orderbook, candles, trades

WebSocket

WebSocket topics

Frame shapes

Operational notes

CLI

HTTP API

Tools and events

Data

Configuration

Documentation Index

​Base URLs

​Data conventions

​REST endpoints

​Heartbeat

​Markets

​Search

​Raw snapshot

​Movers

​Orderbook, candles, trades

​WebSocket

​WebSocket topics

​Frame shapes

​Operational notes

Base URLs

Data conventions

REST endpoints

Heartbeat

Markets

Search

Raw snapshot

Movers

Orderbook, candles, trades

WebSocket

WebSocket topics

Frame shapes

Operational notes