nautechsystems/nautilus_trader · error

RPC parsing of CollectProtocol event is not defined in this

Error message

RPC parsing of CollectProtocol event is not defined in this dex: {}:{}

What it means

Raised by `DexExtended::parse_fee_protocol_collect_event_rpc` when the DEX has no RPC parser registered for the CollectProtocol event (`parse_fee_protocol_collect_event_rpc_fn` is `None`). Protocol-fee collection events are specific to certain V3-fork DEXes; adapters that don't implement an RPC log parser for them bail with the chain and DEX name so callers know the capability gap.

Source

Thrown at crates/adapters/blockchain/src/exchanges/extended.rs:583

                self.dex.chain,
                self.dex.name
            )
        }
    }

    /// Parses a `CollectProtocol` event from an RPC log.
    ///
    /// # Errors
    ///
    /// Returns an error if the DEX does not have an RPC `CollectProtocol` event parser defined or if parsing fails.
    pub fn parse_fee_protocol_collect_event_rpc(
        &self,
        log: &RpcLog,
    ) -> anyhow::Result<FeeProtocolCollectEvent> {
        if let Some(parse_fn) = &self.parse_fee_protocol_collect_event_rpc_fn {
            parse_fn(self.dex.clone(), log)
        } else {
            anyhow::bail!(
                "RPC parsing of CollectProtocol event is not defined in this dex: {}:{}",
                self.dex.chain,
                self.dex.name
            )
        }
    }

    /// Checks if this DEX requires pool initialization events.
    #[must_use]
    pub fn needs_initialization(&self) -> bool {
        self.dex.initialize_event.is_some()
    }

    /// Returns `true` if this DEX can discover pools from HyperSync `PoolCreated` logs.
    ///
    /// `sync-dex` streams `PoolCreated` logs to populate the pool set, so a DEX without this
    /// parser cannot be synced.
    #[must_use]

View on GitHub (pinned to 18893faf8b)

Solutions

1. Register the parser: `parse_fee_protocol_collect_event_rpc_fn: Some(parsing::pancakeswap_v3::fee_protocol_update::parse_fee_protocol_collect_event_rpc)` at DEX construction.
2. Gate the call on `parse_fee_protocol_collect_event_rpc_fn.is_some()` and skip/log unsupported DEXes.
3. Filter CollectProtocol topic0 from your log stream for DEXes without support.
4. Audit the full set of optional parser fns (`parse_*_rpc_fn`) during startup and fail fast if any required ones are missing for your chains.

Example fix

// before
let ev = dex.parse_fee_protocol_collect_event_rpc(&log)?;
// after
let ev = match dex.parse_fee_protocol_collect_event_rpc(&log) {
    Ok(ev) => Some(ev),
    Err(e) if e.to_string().contains("not defined in this dex") => None,
    Err(e) => return Err(e),
};

if dex.parse_fee_protocol_collect_event_rpc_fn.is_none()
    || log.topics.first().map(String::as_str) != Some(COLLECT_PROTOCOL_TOPIC)
{
    return Ok(()); // skip unsupported
}

fn supports_fee_protocol_collect_rpc(dex: &DexExtended) -> bool {
    dex.parse_fee_protocol_collect_event_rpc_fn.is_some()
}

match dex.parse_fee_protocol_collect_event_rpc(&log) {
    Ok(ev) => handle(ev),
    Err(e) if e.to_string().contains("not defined in this dex") => Ok(()),
    Err(e) => Err(e),
}

When it happens

Trigger: Calling `dex.parse_fee_protocol_collect_event_rpc(&log)` on a `DexExtended` constructed without `parse_fee_protocol_collect_event_rpc_fn` — typically when dispatching CollectProtocol logs from an RPC source to an adapter that only registered other event parsers.

Common situations: Indexing protocol-fee revenue across multiple V3-fork DEXes where only some adapters implement CollectProtocol parsing; an adapter version that predates fee-protocol support; wiring the update parser but forgetting the collect parser.

Related errors

• RPC parsing of SetFeeProtocol event is not defined in this d
• RPC parsing of initialize event is not defined in this dex:
• RPC parsing of collect event is not defined in this dex: {}:
• RPC parsing of flash event is not defined in this dex: {}:{}
• RPC parsing of pool created event is not defined in this dex

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/646707059ff764a1. Report an issue: GitHub.