nautechsystems/nautilus_trader · error

Missing data in initialize event log

Error message

Missing data in initialize event log

What it means

parse_initialize_event_hypersync throws this when the Hypersync-decoded Initialize event payload is None, so sqrt_price_x96 and the initial tick cannot be extracted for a newly created V3 pool. The library requires the full decode because both values are mandatory for pool-state initialization. It is the guard at the end of the success path, after topic-based pool/dex extraction.

Source

Thrown at crates/adapters/blockchain/src/exchanges/parsing/uniswap_v3/initialize.rs:83

            Err(e) => anyhow::bail!("Failed to decode initialize event data: {e}"),
        };

        let pool_address = Address::from_slice(
            log.address
                .clone()
                .expect("Contract address should be set in logs")
                .as_ref(),
        );
        let pool_identifier = PoolIdentifier::Address(Ustr::from(&pool_address.to_string()));

        Ok(InitializeEvent::new(
            dex,
            pool_identifier,
            decoded.sqrt_price_x96,
            i32::try_from(decoded.tick)?,
        ))
    } else {
        Err(anyhow::anyhow!("Missing data in initialize event log"))
    }
}

/// Parses an initialize event from an RPC log.
///
/// # Errors
///
/// Returns an error if the log parsing fails or if the event data is invalid.
pub fn parse_initialize_event_rpc(dex: SharedDex, log: &RpcLog) -> anyhow::Result<InitializeEvent> {
    rpc_log::validate_event_signature(log, INITIALIZE_EVENT_SIGNATURE_HASH, "Initialize")?;

    let data_bytes = rpc_log::extract_data_bytes(log)?;

    // Validate if data contains 2 parameters of 32 bytes each (sqrtPriceX96 and tick)
    if data_bytes.len() < 2 * 32 {
        anyhow::bail!("Initialize event data is too short");
    }

View on GitHub (pinned to 18893faf8b)

Solutions

1. Verify the log originates from a canonical Uniswap V3 pool and carries a full 64-byte data section (sqrtPriceX96 + tick).
2. Ensure the Hypersync query decodes Initialize with the correct ABI so decoded is Some.
3. Skip and log logs with empty/short data rather than aborting the ingestion batch.
4. Re-sync the affected range after fixing ABI/client versions.

fn can_parse_initialize(log: &Log) -> bool {
    log.data.len() >= 64 // sqrtPriceX96, tick words
}

fn has_decoded_initialize(decoded: &Option<InitializeDecoded>) -> bool {
    decoded.is_some()
}

match parse_initialize_event_hypersync(&log) {
    Ok(event) => handle(event),
    Err(e) if e.to_string().contains("Missing data in initialize event log") => {
        tracing::warn!("skipping malformed initialize log");
    }
    Err(e) => return Err(e),
}

When it happens

Trigger: Calling parse_initialize_event_hypersync with a log whose decoded field is None — topic0 matched the Initialize signature but the data (sqrtPriceX96, tick) was absent, truncated, or failed Hypersync decoding.

Common situations: First-sync of factory/pool-created blocks where the data section was not fetched; fork contracts emitting Initialize-shaped topics with empty data; Hypersync ABI schema drift; reorg windows delivering partial logs.

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

• Missing data in burn event log
• Missing data in collect event log
• Missing data in mint event log
• Missing data in pool created event log
• Missing data in swap event log

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/21a17a6effe00fec. Report an issue: GitHub.