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

# Rust Configuration

> Configure Rust endpoints, timeouts, reconnects, bounded buffers, and PN1 integrity.

The public endpoints are defaults. Override them only when PolyNode gives you another endpoint.

```rust theme={null}
use polynode::PolyNodeClient;
use std::time::Duration;

let client = PolyNodeClient::builder(std::env::var("POLYNODE_API_KEY")?)
    .base_url("https://api.polynode.dev")
    .ws_url("wss://ws.polynode.dev/ws")
    .ob_url("wss://ob.polynode.dev/ws")
    .rpc_url("https://rpc.polynode.dev")
    .timeout(Duration::from_secs(10))
    .build()?;
```

Configure each stream before connecting:

```rust theme={null}
use polynode::{EngineOptions, PerpsStreamOptions, StreamOptions};

let event_options = StreamOptions {
    compress: true,
    auto_reconnect: true,
    max_reconnect_attempts: None,
    message_buffer_capacity: 4096,
    dedupe_capacity: 4096,
    replay_overlap: Duration::from_millis(1),
    ..Default::default()
};

let orderbook_options = EngineOptions {
    integrity: true,
    allow_stale_reads: false,
    ..Default::default()
};

let perps_options = PerpsStreamOptions {
    auto_reconnect: true,
    message_buffer_capacity: 4096,
    ..Default::default()
};
```

Rust's bounded channels apply backpressure. Poll stream `next()` methods continuously and move expensive work to a bounded worker pipeline. API keys belong in environment variables or a secret manager, never source code, panic messages, or logs.