nautechsystems/nautilus_trader · error

Invalid schema {dbn_schema}

Error message

Invalid schema {dbn_schema}

What it means

`get_range_quotes` dispatches record decoding per schema (mbp-1, tbbo/tcbbo, bbo, cmbp-1, cbbo). The catch-all arm bails when a schema slipped past the earlier validation but has no decode branch — a defensive internal invariant guard indicating the two schema checks in the method are out of sync.

Source

Thrown at crates/adapters/databento/src/historical.rs:468

                    process_record(dbn::RecordRef::from(msg))?;
                }
            }
            dbn::Schema::Bbo1M => {
                while let Some(msg) = decoder.decode_record::<dbn::Bbo1MMsg>().await? {
                    process_record(dbn::RecordRef::from(msg))?;
                }
            }
            dbn::Schema::Bbo1S => {
                while let Some(msg) = decoder.decode_record::<dbn::Bbo1SMsg>().await? {
                    process_record(dbn::RecordRef::from(msg))?;
                }
            }
            dbn::Schema::Cbbo1S | dbn::Schema::Cbbo1M => {
                while let Some(msg) = decoder.decode_record::<dbn::CbboMsg>().await? {
                    process_record(dbn::RecordRef::from(msg))?;
                }
            }
            _ => anyhow::bail!("Invalid schema {dbn_schema}"),
        }

        Ok(result)
    }

    /// Fetches order book depth10 snapshots for the given parameters.
    ///
    /// # Errors
    ///
    /// Returns an error if the API request or data processing fails.
    pub async fn get_range_order_book_depth10(
        &self,
        params: RangeQueryParams,
        depth: Option<usize>,
    ) -> anyhow::Result<Vec<OrderBookDepth10>> {
        let symbols: Vec<&str> = params.symbols.iter().map(String::as_str).collect();
        check_consistent_symbology(&symbols)?;

View on GitHub (pinned to 18893faf8b)

Solutions

1. Check the adapter version against the dbn crate version and upgrade the adapter so validation and dispatch match.
2. Report/fix the mismatch: add the schema to the decode match or remove it from the allow-list.
3. Use only long-standing schemas (mbp-1, tbbo, bbo-1s/1m, cmbp-1, tcbbo, cbbo-1s/1m) until the adapter is fixed.

Example fix

// before
_ => anyhow::bail!("Invalid schema {dbn_schema}"),
// after
_ => anyhow::bail!("Schema {dbn_schema} passed validation but has no decode handler; this is an adapter bug"),

let quotes = get_range_quotes(params).await.unwrap_or_else(|e| {
    assert!(!e.to_string().contains("Invalid schema"), "adapter bug: {e}");
    Vec::new()
});

When it happens

Trigger: A `dbn::Schema` value that passed the allow-list check at the top of `get_range_quotes` but reaches the final `_ =>` arm of the per-schema decode match — normally impossible unless the two match arms diverge after an adapter update.

Common situations: Running a newer Databento dbn crate where new schema variants exist; a code change that added a schema to the validation allow-list but not to the decode dispatch; stale adapter version.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

• Invalid schema. Must be one of: mbp-1, tbbo, bbo-1s, bbo-1m,
• Invalid schema. Must be one of: trades, tbbo, tcbbo, mbp-1,
• Invalid `{SCHEMA_PARAM}` '{schema}'. Must be one of: {allowe
• DBN message type is not currently supported
• Failed to create client builder: {e}

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/754c0355ca940df7. Report an issue: GitHub.