nautechsystems/nautilus_trader · error

Unsupported DEX type {dex_type}; only UniswapV3 is supported

Error message

Unsupported DEX type {dex_type}; only UniswapV3 is supported

What it means

resolve_pool() only supports Uniswap V3 pools. After the venue parses into `(blockchain, dex_type)`, any dex_type other than `DexType::UniswapV3` bails immediately. This execution client implements swap logic, quoter calls, and pool resolution exclusively against Uniswap V3 deployments.

Source

Thrown at crates/adapters/blockchain/src/execution/client.rs:814

            .ok_or_else(|| {
                anyhow::anyhow!(
                    "No registered Uniswap V3 deployment for chain {}",
                    self.chain.name
                )
            })
    }

    fn resolve_pool(&self, instrument_id: &InstrumentId) -> anyhow::Result<Pool> {
        let (blockchain, dex_type) = instrument_id.venue.parse_dex()?;
        if blockchain != self.chain.name {
            anyhow::bail!(
                "Pool venue chain {blockchain} does not match the client chain {}",
                self.chain.name
            );
        }

        if dex_type != DexType::UniswapV3 {
            anyhow::bail!("Unsupported DEX type {dex_type}; only UniswapV3 is supported");
        }

        let pool_identifier = PoolIdentifier::new_checked(instrument_id.symbol.as_str())?;
        if !pool_identifier.is_address() {
            anyhow::bail!(
                "Pool identifier {pool_identifier} is a pool ID; only address identifiers are supported"
            );
        }

        let pool = self
            .core
            .cache()
            .pool(instrument_id)
            .cloned()
            .ok_or_else(|| {
                anyhow::anyhow!(
                    "Unknown pool {instrument_id}; not found in the shared engine cache"
                )

View on GitHub (pinned to 18893faf8b)

Solutions

1. Use an instrument whose venue specifies `uniswap_v3` (e.g. `ethereum/uniswap_v3:0x<pool_address>`), recreating it against the V3 deployment if needed.
2. Route the non-V3 instrument to an execution client/adapter that supports its DEX type instead of this one.
3. If you must trade V2, check the adapter's supported DEX registry (`exchanges::get_dex_extended`) before wiring instruments, and only register instruments for supported types.

Example fix

// before
let id = InstrumentId::from("ethereum/uniswap_v2:0x...-ETH-USD");
client.preflight(&id, ...).await?;

// after
let id = InstrumentId::from("ethereum/uniswap_v3:0x<eth_usdc_pool>");
client.preflight(&id, ...).await?;

let (_chain, dex_type) = instrument_id.venue.parse_dex()?;
if dex_type != DexType::UniswapV3 {
    anyhow::bail!("{dex_type} unsupported by this client; route to a matching adapter");
}
// safe to call client.prepare_swap(...).await?

fn is_uniswap_v3(instrument_id: &InstrumentId) -> anyhow::Result<bool> {
    Ok(instrument_id.venue.parse_dex()?.1 == DexType::UniswapV3)
}

match client.preflight(&instrument_id, quote, slippage).await {
    Err(e) if e.to_string().contains("only UniswapV3 is supported") => {
        warn!("non-V3 instrument routed to V3 client; skipping");
    }
    other => other?,
}

When it happens

Trigger: Calling `preflight`, `restore_swap_plan`, or `prepare_swap` with an `InstrumentId` whose venue encodes a non-V3 DEX — e.g. `ethereum/uniswap_v2`, `base/sushiswap`, or any other registered DEX type. The venue must still parse successfully via `parse_dex()` for this error (not a parse error) to occur.

Common situations: Reusing instruments defined for a V2 strategy against the V3-only execution client; generic swap tooling that accepts arbitrary venues but was pointed at this adapter; migrating a strategy from Uniswap V2 to V3 without updating instrument venue strings; automated venue generation enumerating all registered DEXes.

Related errors

• Dex {dex_id} doesn't exist for chain {}
• Pool identifier {pool_identifier} is a pool ID; only address
• Finalized transaction {} emitted {} Swap logs; expected exac
• DEX {dex_id} is not registered in the data client
• HyperSync parsing of pool created event is not defined in th

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/758f5412d527a014. Report an issue: GitHub.