Errors

Error types and handling

KrakenError

pub enum KrakenError {
    // Connection
    ConnectionFailed { url: String, reason: String },
    WebSocket(String),
    Timeout,

    // Data
    InvalidJson { message: String, raw: String },
    ChecksumMismatch { symbol: String, expected: u32, computed: u32 },

    // Subscription
    SubscriptionRejected { channel: String, reason: String },

    // Rate Limiting
    RateLimited { retry_after: Duration },

    // API
    ApiError { code: i32, message: String, raw: String, recovery: RecoveryHint },

    // Auth
    AuthenticationFailed { reason: String },
    TokenExpired,

    // Trading
    OrderRejected { reason: String },
    InsufficientFunds,
    InvalidSymbol(String),
}

Helper Methods

impl KrakenError {
    /// Returns true if the error may succeed on retry
    pub fn is_retryable(&self) -> bool;

    /// Suggested wait time before retry
    pub fn retry_after(&self) -> Option<Duration>;
}

RecoveryHint

pub enum RecoveryHint {
    RetryAfter(Duration),
    RefreshAuth,
    ContactSupport,
    None,
}

Handling Patterns

Basic

match result {
    Ok(value) => { /* success */ }
    Err(KrakenError::RateLimited { retry_after }) => {
        tokio::time::sleep(retry_after).await;
    }
    Err(KrakenError::AuthenticationFailed { reason }) => {
        log::error!("Auth failed: {}", reason);
    }
    Err(e) => {
        log::error!("Error: {:?}", e);
    }
}

With Retry

if let Err(e) = operation().await {
    if e.is_retryable() {
        let delay = e.retry_after().unwrap_or(Duration::from_secs(1));
        tokio::time::sleep(delay).await;
        // Retry
    }
}

Error Categories

Retryable

Error	Recovery
ConnectionFailed	Wait and retry
RateLimited	Wait retry_after
Timeout	Retry with backoff

Permanent

Error	Action
AuthenticationFailed	Fix credentials
SubscriptionRejected	Fix parameters
InvalidSymbol	Use correct symbol format
InsufficientFunds	Deposit or reduce size

Automatic

Error	SDK Action
ChecksumMismatch	Auto-resync
TokenExpired	Auto-refresh