nautechsystems/nautilus_trader · critical

provider condition {condition_id} does not match instrument

Error message

provider condition {condition_id} does not match instrument condition {instrument_condition}

What it means

Before reconciling an order or fill, the code binds the provider object to the local instrument by comparing condition_id metadata. This error fires when the condition_id from the provider (order or trade) does not match the condition_id stored in the instrument's info metadata (case-insensitively), meaning the order/fill belongs to a different market than the instrument.

Source

Thrown at crates/adapters/polymarket/src/execution/reconciliation.rs:252

        trade_id,
    })
}

fn validate_instrument_binding(
    instrument: &InstrumentAny,
    condition_id: &str,
    outcome: PolymarketOutcome,
) -> anyhow::Result<()> {
    let InstrumentAny::BinaryOption(binary) = instrument else {
        anyhow::bail!("expected Polymarket BinaryOption instrument, found {instrument:?}");
    };
    let instrument_condition = binary
        .info
        .as_ref()
        .and_then(|info| info.get_str("condition_id"))
        .context("Polymarket instrument is missing condition_id metadata")?;

    anyhow::ensure!(
        instrument_condition.eq_ignore_ascii_case(condition_id),
        "provider condition {condition_id} does not match instrument condition {instrument_condition}",
    );
    let instrument_outcome = binary
        .outcome
        .context("Polymarket instrument is missing outcome metadata")?;
    anyhow::ensure!(
        instrument_outcome == outcome.as_str(),
        "provider outcome {outcome} does not match instrument outcome {instrument_outcome}",
    );

    Ok(())
}

fn validate_quantity_evidence(
    value: Decimal,
    precision: u8,
    field: &str,

View on GitHub (pinned to 18893faf8b)

Solutions

1. Print both condition_ids and confirm which is correct; refetch the market definition from Polymarket.
2. Rebuild the instrument from the current market metadata so info.condition_id matches the live market.
3. Check the instrument/venue configuration for a copied or outdated condition_id.
4. Verify any instrument cache is invalidated when the market is re-created or resolved.

Example fix

// before
let instrument = load_instrument_cached(symbol)?;
validate_instrument_binding(&order, &instrument)?;
// after: refresh instrument when condition ids diverge
let instrument = load_instrument_cached(symbol)?;
if !condition_matches(&order, &instrument) {
    let instrument = reload_instrument_from_provider(symbol)?;
    validate_instrument_binding(&order, &instrument)?;
}

fn condition_matches(instrument: &Instrument, condition_id: &str) -> bool {
    instrument.info.as_ref()
        .and_then(|i| i.get_str("condition_id"))
        .map(|c| c.eq_ignore_ascii_case(condition_id))
        .unwrap_or(false)
}

fn bound_to_condition(instrument: &Instrument, condition_id: &str) -> Option<&Instrument> {
    condition_matches(instrument, condition_id).then_some(instrument)
}

match validate_instrument_binding(&order, &instrument) {
    Ok(()) => (),
    Err(e) if e.to_string().contains("condition") => reload_instrument_and_retry(&symbol)?,
    Err(e) => return Err(e),
}

When it happens

Trigger: build_order_report_from_order, classify_target_trade, or build_fill_reports_from_trades -> validate_instrument_binding is called with a provider object whose condition_id differs from binary.info["condition_id"].

Common situations: Subscribing/reconciling with an instrument built from a stale market config while the venue moved the market to a new condition_id; hardcoding or mis-copying a token/condition id in config; a market resolved and re-deployed with a new condition id.

Understand the failure class

Background: "Must be a positive integer", "Invalid value", "Unsupported": the invalid-argument-value error family, when a library rejects the value you pass — this error's family across 35 libraries.

Related errors

• provider outcome {outcome} does not match instrument outcome
• Polymarket execution shutdown failed: {}
• Polymarket CLOB protocol version {version} is unsupported; a
• provider venue order {} is not owned by the account
• unmapped in-scope open order instrument {instrument_id} (tok

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/feb0f6c2ba1dbdd3. Report an issue: GitHub.