Finalized Swap input {quote_amount} does not match the persi

Error message

Finalized Swap input {quote_amount} does not match the persisted amount {}

What it means

For BUY orders, the finalized Swap event's quote-side amount must be positive and equal in absolute value to the persisted plan.amount_in, since for a BUY the quote token is the input. A mismatch means the on-chain quote input differs from the recorded plan amount.

Source

Thrown at crates/adapters/blockchain/src/execution/client.rs:4785

        })?;
    let event = dex.parse_swap_event_rpc(log)?;
    let (base_amount, quote_amount) =
        if plan.pool.get_base_token().address == plan.pool.token0.address {
            (event.amount0, event.amount1)
        } else {
            (event.amount1, event.amount0)
        };
    let last_qty = match plan.order.order_side() {
        OrderSide::Sell => {
            anyhow::ensure!(
                base_amount.is_positive() && base_amount.unsigned_abs() == plan.amount_in,
                "Finalized Swap input {base_amount} does not match the persisted amount {}",
                plan.amount_in
            );
            plan.order.quantity()
        }
        OrderSide::Buy => {
            anyhow::ensure!(
                quote_amount.is_positive() && quote_amount.unsigned_abs() == plan.amount_in,
                "Finalized Swap input {quote_amount} does not match the persisted amount {}",
                plan.amount_in
            );
            anyhow::ensure!(
                base_amount.is_negative(),
                "Finalized Swap base amount {base_amount} is not a BUY output"
            );
            raw_amount_to_quantity(
                base_amount.unsigned_abs(),
                plan.pool.get_base_token().decimals,
            )?
        }
    };

    let block = &included.finality.inclusion_header;
    anyhow::ensure!(
        block.number == included.block_number

View on GitHub (pinned to 18893faf8b)

Solutions

Check that the base/quote selection branch matches the pool's token ordering
Persist amount_in with the same decimals/units the RPC decoder emits
If the route splits input across multiple pools, sum per-pool inputs rather than comparing plan.amount_in to one leg
Verify the log corresponds to this plan's swap (tx hash, log index) before comparing amounts

Defensive patterns

Strategy: validation

Validate before calling

if order_side == OrderSide::Buy && !(quote_amount.is_positive() && quote_amount.unsigned_abs() == plan.amount_in) {
    return Err(anyhow!("BUY input mismatch: event={} plan={}", quote_amount, plan.amount_in));
}

Try / catch

if let Err(e) = verify_finalized_swap(...).await {
    if e.to_string().contains("does not match the persisted amount") {
        reconcile_with_route_splits(tx_hash).await?;
    } else { return Err(e); }
}

Prevention

Persist amount_in in the same units the RPC decoder emits
Map amount0/amount1 to base/quote once, centrally, from token ordering
Handle aggregator routes that split input across pools by summing legs
Confirm the log belongs to this plan's swap before comparing amounts

When it happens

Trigger: Verifying a BUY swap where the selected quote amount is <= 0 or unsigned_abs() != plan.amount_in — caused by wrong base/quote amount mapping (amount0 vs amount1), a plan whose recorded input was changed, or the log belonging to a different swap in the same transaction.

Common situations: Token0/token1 ordering confusion between pool metadata and decoder output; amount_in persisted in different units (wei vs token decimals); executing via an aggregator that split the input across pools so this pool's input is smaller than the plan total.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/735b8a0274c4be1b. Report an issue: GitHub.