nautechsystems/nautilus_trader · error

Unsupported hour interval: {step}h

Error message

Unsupported hour interval: {step}h

What it means

bar_spec_to_binance_interval supports hour steps 1, 2, 4, 6, 8 and 12 — the exact set of Binance hourly kline intervals (1h, 2h, 4h, 6h, 8h, 12h). Other hour steps such as 3h or 24h have no native interval and bail with this message (24h should be expressed as 1-DAY).

Source

Thrown at crates/adapters/binance/src/common/parse.rs:1454

            1 => BinanceKlineInterval::Second1,
            _ => anyhow::bail!("Unsupported second interval: {step}s"),
        },
        BarAggregation::Minute => match step {
            1 => BinanceKlineInterval::Minute1,
            3 => BinanceKlineInterval::Minute3,
            5 => BinanceKlineInterval::Minute5,
            15 => BinanceKlineInterval::Minute15,
            30 => BinanceKlineInterval::Minute30,
            _ => anyhow::bail!("Unsupported minute interval: {step}m"),
        },
        BarAggregation::Hour => match step {
            1 => BinanceKlineInterval::Hour1,
            2 => BinanceKlineInterval::Hour2,
            4 => BinanceKlineInterval::Hour4,
            6 => BinanceKlineInterval::Hour6,
            8 => BinanceKlineInterval::Hour8,
            12 => BinanceKlineInterval::Hour12,
            _ => anyhow::bail!("Unsupported hour interval: {step}h"),
        },
        BarAggregation::Day => match step {
            1 => BinanceKlineInterval::Day1,
            3 => BinanceKlineInterval::Day3,
            _ => anyhow::bail!("Unsupported day interval: {step}d"),
        },
        BarAggregation::Week => match step {
            1 => BinanceKlineInterval::Week1,
            _ => anyhow::bail!("Unsupported week interval: {step}w"),
        },
        BarAggregation::Month => match step {
            1 => BinanceKlineInterval::Month1,
            _ => anyhow::bail!("Unsupported month interval: {step}M"),
        },
        agg => anyhow::bail!("Unsupported bar aggregation for Binance: {agg:?}"),
    };

    Ok(interval)

View on GitHub (pinned to a4b06ed870)

Solutions

1. Remap the step onto a supported interval: 24-HOUR becomes 1-DAY, 3-HOUR becomes 1-HOUR/4-HOUR.
2. Or use INTERNAL aggregation (e.g. 3-HOUR-LAST-INTERNAL) to keep the exact step locally.
3. Validate BarType strings in config before startup.

Example fix

// before
// let bar_type = BarType::from("3-HOUR-LAST-EXTERNAL");
// -> Unsupported hour interval: 3h

// after
// let bar_type = BarType::from("3-HOUR-LAST-INTERNAL"); // aggregated locally
// or
// let bar_type = BarType::from("4-HOUR-LAST-EXTERNAL"); // nearest venue interval

fn supported_hour_step(step: u32) -> bool {
    matches!(step, 1 | 2 | 4 | 6 | 8 | 12)
}

fn is_supported_hour_bar(step: u32) -> bool {
    matches!(step, 1 | 2 | 4 | 6 | 8 | 12)
}

let bar_type = BarType::from("3-HOUR-LAST-EXTERNAL");
if let Err(e) = data_client.subscribe_bars(bar_type) {
    if e.to_string().contains("Unsupported hour interval") {
        // fall back: 4-HOUR external or 3-HOUR-LAST-INTERNAL
    } else {
        return Err(e);
    }
}

When it happens

Trigger: Requesting Binance bars with an hour step outside {1, 2, 4, 6, 8, 12} — commonly 3-HOUR or 24-HOUR specifications.

Common situations: Configs ported from venues with arbitrary hour klines; sessions defined as 3h blocks; 24-HOUR used where 1-DAY is meant.

Related errors

• Unsupported second interval: {step}s
• Unsupported minute interval: {step}m
• Unsupported day interval: {step}d
• Unsupported week interval: {step}w
• Only EXTERNAL aggregation is supported

AI-assisted analysis of nautechsystems/nautilus_trader@a4b06ed870 (2026-08-16). Data as JSON: /api/errors/76afac300d9b74c7. Report an issue: GitHub.