> ## Documentation Index
> Fetch the complete documentation index at: https://miny.mintlify.app/llms.txt
> Use this file to discover all available pages before exploring further.

# Builder

> Configuration options for KrakenClient

## Basic

```rust theme={null}
let client = KrakenClient::builder(vec!["BTC/USD".into()])
    .with_depth(Depth::D10)
    .with_book(true)
    .connect()
    .await?;
```

## Subscriptions

### Symbols

```rust theme={null}
// Single symbol
KrakenClient::builder(vec!["BTC/USD".into()])

// Multiple symbols
KrakenClient::builder(vec![
    "BTC/USD".into(),
    "ETH/USD".into(),
    "SOL/USD".into(),
])
```

<Note>
  Use Kraken's symbol format: `"BTC/USD"` not `"BTCUSD"` or `"BTC-USD"`.
</Note>

### Depth

```rust theme={null}
.with_depth(Depth::D10)   // 10 levels (fastest)
.with_depth(Depth::D25)   // 25 levels
.with_depth(Depth::D100)  // 100 levels
.with_depth(Depth::D500)  // 500 levels
.with_depth(Depth::D1000) // 1000 levels (most data)
```

### Channels

```rust theme={null}
.with_book(true)      // L2 orderbook
.with_ticker(true)    // Ticker updates
.with_trade(true)     // Trade executions
.with_ohlc(OhlcInterval::M1)  // 1-minute candles
```

### L3 Orderbook

```rust theme={null}
// L3 requires separate endpoint and Kraken approval
.with_l3(vec!["BTC/USD".into()])
```

## Connection

### Timeout

```rust theme={null}
.with_timeout(Duration::from_secs(30))
```

### Reconnection

```rust theme={null}
use kraken_sdk::ReconnectConfig;

.with_reconnect(ReconnectConfig {
    initial_delay: Duration::from_millis(100),
    max_delay: Duration::from_secs(30),
    multiplier: 2.0,
    max_attempts: None,  // Unlimited
})

// Disable reconnection
.without_reconnect()
```

### Circuit Breaker

```rust theme={null}
use kraken_sdk::CircuitBreakerConfig;

.with_circuit_breaker(CircuitBreakerConfig {
    failure_threshold: 5,
    reset_timeout: Duration::from_secs(30),
    half_open_timeout: Duration::from_secs(60),
})
```

## Channel Settings

### Capacity & Backpressure

```rust theme={null}
use kraken_sdk::BackpressurePolicy;

.with_channel_capacity(2048, BackpressurePolicy::DropNewest)
```

| Policy       | Behavior                    |
| ------------ | --------------------------- |
| `DropNewest` | Discard incoming when full  |
| `DropOldest` | Discard oldest to make room |
| `Block`      | Block sender until space    |

### Event Filtering

```rust theme={null}
use kraken_sdk::EventFilter;

.with_event_filter(
    EventFilter::new()
        .only_market()
        .exclude_heartbeats()
)
```

## Observability

```rust theme={null}
use kraken_sdk::Hooks;

.with_hooks(
    Hooks::new()
        .on_connect(|info| log::info!("Connected"))
        .on_disconnect(|reason| log::warn!("Disconnected: {:?}", reason))
        .on_latency(|micros| metrics::histogram!("latency", micros))
)
```

## Complete Example

```rust theme={null}
let client = KrakenClient::builder(vec!["BTC/USD".into(), "ETH/USD".into()])
    // Subscriptions
    .with_depth(Depth::D25)
    .with_book(true)
    .with_ticker(true)

    // Connection
    .with_timeout(Duration::from_secs(30))
    .with_reconnect(ReconnectConfig::default())
    .with_circuit_breaker(CircuitBreakerConfig::default())

    // Channel
    .with_channel_capacity(2048, BackpressurePolicy::DropNewest)
    .with_event_filter(EventFilter::new().exclude_heartbeats())

    // Observability
    .with_hooks(
        Hooks::new()
            .on_connect(|_| log::info!("Connected"))
    )

    .connect()
    .await?;
```