# Market data

Read candles, public trades, order books, and market overview, no credentials required.

Unary market-data calls are public. Realtime is always included; the legacy `realtime` Cargo feature is a no-op compatibility flag. Subscribe helpers usually need hydrated catalogs for symbol resolution. There is no `client.candles` alias, use `client.market_data`.

```rust
use polyester::{Client, Config};

let client = Client::new(Config { hydrate_catalogs: true, ..Default::default() })?;
client.wait_for_catalogs().await?;
```

Typed streams use `recv().await`. Managed order-book / overview books use `updates().recv().await`.

## Symbols

Prefer `"BTC-USDT"`. Call `wait_for_catalogs().await?` before symbol-string subscribe helpers.

## Market overview

```rust
use polyester::services::{ListMarketOverviewOptions, MarketOverviewCreateSubscriptionOptions};

let overview = client.market_overview.list(Some(50)).await?;
println!("{} markets", overview.markets.len());
let mut sub = client
    .market_overview
    .create_subscription(MarketOverviewCreateSubscriptionOptions {
        limit: Some(50),
        ..Default::default()
    })
    .await?;
while let Some(rows) = sub.updates().recv().await { let _ = rows; break; }
```

## Candles

```rust
let result = client.market_data.get_candles("BTC-USDT", "1h", Some(200)).await?;
let mut live = client.market_data.subscribe_candles("BTC-USDT", "1m").await?;
while let Some(c) = live.recv_result().await? { println!("{}", c.close); break; }
```

Row candle results are newest-first, with an included open candle prepended; use `.first()` for latest and reverse/sort by `ts_sec` for indicators. Candle columns are oldest-first.

## Order book

```rust
use polyester::services::CreateSubscriptionOptions;

let book = client.orderbook.get("BTC-USDT", Some(20)).await?;
let mut sub = client
    .orderbook
    .create_subscription(CreateSubscriptionOptions {
        symbol: "BTC-USDT".into(),
        depth: Some(50),
        ..Default::default()
    })
    .await?;
while let Some(b) = sub.updates().recv().await { println!("{}", b.book_seq); break; }
```

## Public trades

```rust
let tape = client.market_data.get_trades("BTC-USDT", Some(20)).await?;
let mut sub = client.market_data.subscribe_trades("BTC-USDT").await?;
while let Some(t) = sub.recv_result().await? { println!("{:?}", t.price); break; }
```

Private fills are `client.trades`, not the public tape.

## Heatmap & chain analytics

`client.heatmap` and `client.chain_analytics` for L2 heatmap and chain analytics reads.

> **Streaming model**
>
> Centrifugo WebSocket + Protobuf. Details: [Streaming](https://testnet.polyester.com/docs/sdk/rust/guides/streaming).

## Related

- [Order book](https://testnet.polyester.com/docs/sdk/rust/reference/order-book)
- [Candles](https://testnet.polyester.com/docs/sdk/rust/reference/candles)
- [Public trades](https://testnet.polyester.com/docs/sdk/rust/reference/public-trades)
- [Market overview](https://testnet.polyester.com/docs/sdk/rust/reference/market-overview)