nautechsystems/nautilus_trader · error · anyhow::Error

Trailing stop orders are not yet supported on the Kraken WS

Error message

Trailing stop orders are not yet supported on the Kraken WS path; use REST

What it means

build_add_order_params converts a Nautilus order command into Kraken Spot WS v2 addOrder parameters. Trailing stop orders (TrailingStopMarket/TrailingStopLimit) have no supported mapping on the WS path yet, so the builder explicitly bails and directs users to the Kraken REST execution path.

Source

Thrown at crates/adapters/kraken/src/common/order_params.rs:65

    cmd: &SubmitOrder,
    order: &OrderAny,
    token: SecretString,
    leverage: Option<u16>,
) -> anyhow::Result<KrakenWsAddOrderParams> {
    let order_type = order.order_type();
    let order_side = order.order_side();
    let time_in_force = order.time_in_force();

    let side = match order_side {
        OrderSide::Buy => KrakenOrderSide::Buy,
        OrderSide::Sell => KrakenOrderSide::Sell,
    };

    if matches!(
        order_type,
        OrderType::TrailingStopMarket | OrderType::TrailingStopLimit
    ) {
        anyhow::bail!("Trailing stop orders are not yet supported on the Kraken WS path; use REST",);
    }

    if order.display_qty().is_some() {
        anyhow::bail!(
            "Iceberg (display_qty) orders are not supported on the Kraken WS path; use REST"
        );
    }

    let kraken_order_type = match order_type {
        OrderType::Market => KrakenOrderType::Market,
        OrderType::Limit => KrakenOrderType::Limit,
        OrderType::StopMarket => KrakenOrderType::StopLoss,
        OrderType::StopLimit => KrakenOrderType::StopLossLimit,
        OrderType::MarketIfTouched => KrakenOrderType::TakeProfit,
        OrderType::LimitIfTouched => KrakenOrderType::TakeProfitLimit,
        _ => anyhow::bail!("Unsupported order type for Kraken WS: {order_type:?}"),
    };

View on GitHub (pinned to 18893faf8b)

Solutions

Route trailing stop orders through the Kraken REST execution path instead of the WS path.
Change the strategy to use plain StopMarket/StopLimit orders if WS execution is required.
Track adapter updates: WS support for trailing stops may be added later; feature-gate trailing stops off for Kraken WS until then.

Example fix

// before
exec_client.submit(order); // routed to WS, order type = TrailingStopMarket
// after
if matches!(order.order_type(), OrderType::TrailingStopMarket | OrderType::TrailingStopLimit) {
    rest_exec_client.submit(order); // use REST adapter for trailing stops
} else {
    ws_exec_client.submit(order);
}

Defensive patterns

Strategy: validation

Validate before calling

if matches!(order.order_type(), OrderType::TrailingStopMarket | OrderType::TrailingStopLimit) {
    // route to REST client or reject at strategy level before reaching WS
}

Try / catch

match ws_client.submit(order).await {
    Err(e) if e.to_string().contains("Trailing stop orders are not yet supported") => {
        // fall back to REST execution or disable trailing stops
    }
    result => result?,
}

Prevention

Feature-gate trailing stop order types off in strategy configs targeting Kraken WS.
Document per-venue order-type support in strategy config reviews.
Add a pre-trade filter that rejects unsupported order types per execution client.

When it happens

Trigger: Submitting an order of type TrailingStopMarket or TrailingStopLimit through the Kraken WebSocket execution client (submit_via_ws -> build_add_order_params).

Common situations: A strategy config generates trailing-stop orders (e.g. trailing stop loss on positions) while the adapter's execution routing is set to WebSocket instead of REST.

Understand the failure class

Background: UnsupportedOperationException and "is not supported" errors: when a library deliberately refuses a call — this error's family across 30 libraries.

Related errors

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/f005666bf3f33547. Report an issue: GitHub.