nautechsystems/nautilus_trader · error

Unknown DEX {dex_id} on chain {}

Error message

Unknown DEX {dex_id} on chain {}

What it means

register_dex validates that the requested DEX type exists for the target chain via get_dex_extended. If there is no registry entry for this DEX on this chain (e.g. SushiSwap on a chain where it isn't indexed), registration cannot proceed and the error names both the DEX and chain.

Source

Thrown at crates/adapters/blockchain/src/data/core.rs:1430

    /// absent from the cache database is left for the caller's later lookup to report.
    ///
    /// # Errors
    ///
    /// Returns an error if DEX registration or the pool load fails.
    pub async fn register_dex_exchange_for_pool(
        &mut self,
        dex_id: DexType,
        pool_identifier: &PoolIdentifier,
    ) -> anyhow::Result<()> {
        self.register_dex(dex_id).await?;
        let _ = self.cache.load_pool(&dex_id, pool_identifier).await?;
        Ok(())
    }

    /// Registers a DEX in the cache and its event signatures for subscriptions, without loading pools.
    async fn register_dex(&mut self, dex_id: DexType) -> anyhow::Result<()> {
        let Some(dex_extended) = get_dex_extended(self.chain.name, &dex_id) else {
            anyhow::bail!("Unknown DEX {dex_id} on chain {}", self.chain.name);
        };

        log::debug!("Registering DEX {dex_id} on chain {}", self.chain.name);
        self.cache.add_dex(dex_extended.dex.clone()).await?;
        self.subscription_manager.register_dex_for_subscriptions(
            dex_id,
            dex_extended.swap_created_event.as_ref(),
            dex_extended.mint_created_event.as_ref(),
            dex_extended.burn_created_event.as_ref(),
            dex_extended.collect_created_event.as_ref(),
            dex_extended.flash_created_event.as_deref(),
        );
        self.subscription_manager.register_dex_fee_protocol_events(
            dex_id,
            dex_extended.fee_protocol_update_event.as_deref(),
            dex_extended.fee_protocol_collect_event.as_deref(),
        );
        Ok(())

View on GitHub (pinned to 18893faf8b)

Solutions

1. Check the supported DEX list for your chain and pick a valid DexType
2. Correct the chain configuration if the DEX should exist on it
3. Upgrade the library/dex-metadata dependency if the DEX was recently added upstream

Example fix

// before
client.register_dex_exchange(chain, DexType::Camelot).await?; // not on this chain
// after
client.register_dex_exchange(chain, DexType::UniswapV3).await?; // supported on this chain

if get_dex_extended(chain.name, dex_id).is_none() {
    return Err(anyhow::anyhow!("DEX {:?} unsupported on {}", dex_id, chain.name));
}
client.register_dex_exchange(chain, dex_id).await?;

if let Err(e) = client.register_dex_exchange(chain, dex).await {
    if e.to_string().starts_with("Unknown DEX") {
        log::warn!("{} unsupported on {}; skipping", dex, chain.name);
        return Ok(()); // or fall back to a supported DEX
    }
    return Err(e);
}

When it happens

Trigger: Calling register_dex (directly or via register_dex_exchange / register_dex_exchange_for_pool) with a DexType not supported/indexed on the configured chain.

Common situations: Configuring a DEX on the wrong chain in the adapter config; typo in DEX id; DEX not yet supported by the underlying dex metadata registry for that network.

Understand the failure class

Background: Invalid enum value errors: "Unknown type", "Invalid scope", "must be one of" — when a string is not on the library's allowed list — this error's family across 23 libraries.

Related errors

• Dex {dex_id} doesn't exist for chain {}
• No DEX extended found for {} on {}
• DEX {dex_id:?} has not been registered
• no Lighter market_index registered for instrument {instrumen
• DEX '{dex_type}' is not registered on chain '{}'

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/c39e3f04a65b531d. Report an issue: GitHub.