nautechsystems/nautilus_trader · error

Missing data in mint event log

Error message

Missing data in mint event log

What it means

parse_mint_event_hypersync throws this when the Hypersync-decoded Mint event payload is None, so the mint amount, amount0, amount1, and tick bounds cannot be populated. The library will not fabricate a Mint event from topic data alone since the amounts live in the data section. This is the standard fallback branch of the uniswap_v3 hypersync parsers.

Source

Thrown at crates/adapters/blockchain/src/exchanges/parsing/uniswap_v3/mint.rs:116

        );
        let pool_identifier = PoolIdentifier::Address(Ustr::from(&pool_address.to_string()));
        Ok(MintEvent::new(
            dex,
            pool_identifier,
            extract_block_number(log)?,
            extract_transaction_hash(log)?,
            extract_transaction_index(log)?,
            extract_log_index(log)?,
            decoded.sender,
            owner,
            tick_lower,
            tick_upper,
            decoded.amount,
            decoded.amount0,
            decoded.amount1,
        ))
    } else {
        Err(anyhow::anyhow!("Missing data in mint event log"))
    }
}

/// Parses a mint event from an RPC log.
///
/// # Errors
///
/// Returns an error if the log parsing fails or if the event data is invalid.
pub fn parse_mint_event_rpc(dex: SharedDex, log: &RpcLog) -> anyhow::Result<MintEvent> {
    rpc_log::validate_event_signature(log, MINT_EVENT_SIGNATURE_HASH, "Mint")?;

    let owner = rpc_log::extract_address_from_topic(log, 1, "owner")?;

    // Extract int24 tickLower from topic2 (stored as a 32-byte padded value)
    let tick_lower_bytes = rpc_log::extract_topic_bytes(log, 2)?;
    let tick_lower = i32::from_be_bytes(tick_lower_bytes[28..32].try_into()?);

    // Extract int24 tickUpper from topic3 (stored as a 32-byte padded value)

View on GitHub (pinned to 18893faf8b)

Solutions

1. Confirm the log's data section exists and holds the expected 32-byte words for the Mint event.
2. Verify the Hypersync Mint ABI registration so decoding returns Some(decoded).
3. Filter non-conforming logs upstream and log them instead of letting the batch fail.
4. Bump/re-align adapter and Hypersync client versions and re-fetch the range.

fn can_parse_mint(log: &Log) -> bool {
    log.data.len() >= 96 // amount, amount0, amount1 words
}

fn has_decoded_mint(decoded: &Option<MintDecoded>) -> bool {
    decoded.is_some()
}

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

When it happens

Trigger: Calling parse_mint_event_hypersync with a log whose decoded field is None — topic0 matched the Mint signature but the data section was missing, truncated, or failed Hypersync decoding into the expected Mint struct.

Common situations: Non-standard contracts emitting Mint-shaped topic0 without data; Hypersync ABI drift after adapter updates; partially indexed logs during reorgs; hand-built test logs missing the data field.

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 initialize 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/8b82a5f7706a1437. Report an issue: GitHub.