nautechsystems/nautilus_trader · error

Lighter does not offer {bar_type} on the candle WebSocket st

Error message

Lighter does not offer {bar_type} on the candle WebSocket stream

What it means

The requested bar type maps to a Lighter candle resolution that is not streamable over the candle WebSocket channel. Lighter only exposes certain resolutions via WebSocket; others must be polled over HTTP. The adapter rejects the subscription up front rather than silently degrading.

Source

Thrown at crates/adapters/lighter/src/data/mod.rs:1258

    ) -> anyhow::Result<()> {
        let instrument_id = subscription.instrument_id;

        let channel = self.perp_market_stats_channel(instrument_id, "funding rate")?;
        self.activate_market_stats_subscription(
            instrument_id,
            channel,
            MarketStatsKind::FundingRate,
            "funding rate",
        );

        Ok(())
    }

    fn subscribe_bars(&mut self, subscription: SubscribeBars) -> anyhow::Result<()> {
        let bar_type = subscription.bar_type;

        let resolution = LighterCandleResolution::try_from(&bar_type)?;
        anyhow::ensure!(
            resolution.is_ws_streamable(),
            "Lighter does not offer {bar_type} on the candle WebSocket stream",
        );

        let instrument_id = bar_type.instrument_id();
        if !self.instruments.contains_key(&instrument_id) {
            return Err(InstrumentLookupError::not_found(instrument_id).into());
        }

        let ws = self.ws_client.clone();
        self.spawn_task(async move {
            if let Err(e) = ws.subscribe_candles(instrument_id, resolution).await {
                log::error!("Failed to subscribe to Lighter candles for {bar_type}: {e:?}");
            }
        });

        Ok(())
    }

View on GitHub (pinned to 18893faf8b)

Solutions

1. Choose a resolution that Lighter streams over WebSocket (check LighterCandleResolution::is_ws_streamable for supported values).
2. Switch the bar subscription to an aggregation built from a smaller WS-streamable resolution.
3. Use request_bars (HTTP polling) instead of a live WebSocket subscription for non-streamable resolutions.
4. Validate the BarType spec string (e.g. LIGHTER-PERP-1-MINUTE.LIGHTER) before configuring the subscription.

Example fix

// before
client.subscribe_bars(SubscribeBars::new(BarType::parse("LIGHTER-PERP-1-DAY.LIGHTER")?));
// after
client.subscribe_bars(SubscribeBars::new(BarType::parse("LIGHTER-PERP-1-MINUTE.LIGHTER")?));

let bar_type = BarType::parse("LIGHTER-PERP-1-MINUTE.LIGHTER")?;
let res = LighterCandleResolution::try_from(&bar_type)?;
if !res.is_ws_streamable() {
    // fall back to request_bars over HTTP
}

match client.subscribe_bars(sub) {
    Err(e) if e.to_string().contains("candle WebSocket stream") => {
        client.request_bars(sub.bar_type).await?; // HTTP fallback
    }
    r => r?,
}

When it happens

Trigger: Calling subscribe_bars() (or requesting bars via a data engine) with a BarType whose aggregation/resolution maps to a LighterCandleResolution where is_ws_streamable() is false.

Common situations: Subscribing to long-interval candles (e.g. 1D bars) expecting WebSocket delivery; copying a bar spec valid on another exchange into a Lighter config.

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

• WS user data subscription timed out
• subscription confirmation failed: {e}
• Unsupported Deribit resolution: {resolution}
• invalid Derive subscription channel `{channel}`
• Failed to send UpdateInstrument command: {e}

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/9088f9120b1c5d57. Report an issue: GitHub.