nautechsystems/nautilus_trader · error

DeribitBookSummary requests require metadata['currency']

Error message

DeribitBookSummary requests require metadata['currency']

What it means

Subscribing to DeribitBookSummary data requires the request metadata to specify the currency (e.g. BTC, ETH) because the underlying ticker.book_summary channels are per currency/kind. book_summary_metadata_currency extracts metadata["currency"], trims/uppercases it, and raises this error when the metadata is missing, empty, or whitespace-only.

Source

Thrown at crates/adapters/deribit/src/data.rs:497

    }

    fn subscribe_combo_legs(params: &Option<Params>) -> bool {
        params
            .as_ref()
            .and_then(|params| params.get_bool("subscribe_combo_legs"))
            .unwrap_or(false)
    }

    fn book_summary_metadata_currency(data_type: &DataType) -> anyhow::Result<String> {
        data_type
            .metadata()
            .and_then(|m| m.get("currency"))
            .and_then(|v| v.as_str())
            .map(str::trim)
            .filter(|value| !value.is_empty())
            .map(str::to_ascii_uppercase)
            .ok_or_else(|| {
                anyhow::anyhow!("DeribitBookSummary requests require metadata['currency']")
            })
    }

    fn book_summary_metadata_kind(data_type: &DataType) -> Option<String> {
        data_type
            .metadata()
            .and_then(|m| m.get("kind"))
            .and_then(|v| v.as_str())
            .map(str::trim)
            .filter(|value| !value.is_empty())
            .map(str::to_ascii_lowercase)
    }

    fn book_summary_data_type(currency: &str, kind: Option<&str>) -> DataType {
        let mut metadata = Params::new();
        metadata.insert(
            "currency".to_string(),
            serde_json::Value::String(currency.to_string()),

View on GitHub (pinned to 18893faf8b)

Solutions

1. Pass metadata={"currency": "BTC"} (uppercase, e.g. BTC/ETH/SOL/USDC) when requesting DeribitBookSummary data.
2. Verify the key is exactly "currency" and non-empty after trimming.
3. If currency should be derived, set it from the instrument's venue/currency before subscribing.

Example fix

// before
let data_type = DataType::new(DeribitBookSummary::default(), None);
data_engine.subscribe(&data_type)?;

// after
let data_type = DataType::new(DeribitBookSummary::default(), Some(indexmap! { "currency" => "BTC" }));
data_engine.subscribe(&data_type)?;

// Rust
let currency = metadata
    .as_ref()
    .and_then(|m| m.get("currency"))
    .and_then(|v| v.as_str())
    .map(str::trim)
    .filter(|s| !s.is_empty());
anyhow::ensure!(currency.is_some(), "DeribitBookSummary requires metadata['currency']");

fn has_currency(data_type: &DataType) -> bool {
    data_type
        .metadata()
        .as_ref()
        .and_then(|m| m.get("currency"))
        .and_then(|v| v.as_str())
        .map(|s| !s.trim().is_empty())
        .unwrap_or(false)
}

match book_summary_metadata_currency(&data_type) {
    Ok(ccy) => subscribe_book_summaries(ccy).await?,
    Err(e) => return Err(anyhow!("fix subscription metadata: {e}")),
}

When it happens

Trigger: Requesting BookSummary data via the DataEngine with a DataType whose metadata dict lacks a "currency" key, contains an empty string, or only whitespace — e.g. subscribing to DeribitBookSummary(None) without passing metadata={"currency": "BTC"}.

Common situations: Copy-pasting a subscribe call for another Deribit data type that doesn't require currency; building the DataType programmatically and forgetting the metadata dict; typos in the key name ("Currency", "curr").

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• Instrument {instrument_id} not found and `auto_load_missing_
• Deribit only supports L2_MBP order book deltas
• Deribit only supports L2_MBP order book depth
• InstrumentState channel requires kind and currency parameter
• custom data request requires `instrument_id` metadata

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/0404fbb74d9ddf85. Report an issue: GitHub.