nautechsystems/nautilus_trader · error

{e}

Error message

{e}

What it means

request_instruments_by_slugs_with_retry executes the retried Gamma API request and maps any remaining error into anyhow with this message. It means the instrument fetch from the Gamma /events endpoint failed after retry attempts.

Source

Thrown at crates/adapters/polymarket/src/http/gamma.rs:660

                                parse_markets_to_instruments(&markets, ts_init)
                            })
                            .collect();

                        if instruments.is_empty() {
                            return Err(Error::transport(
                                "Gamma returned no instruments (indexing lag)",
                            ));
                        }

                        Ok(instruments)
                    }
                },
                |e| e.is_retryable(),
                |e| Error::transport(e.to_string()),
            )
            .execute()
            .await
            .map_err(|e| anyhow::anyhow!("{e}"))
    }

    /// Fetches instruments from event slugs concurrently.
    ///
    /// Each slug queries `GET /events?slug=`, extracts the markets array from
    /// the first matching event, and parses each market into instruments.
    pub async fn request_instruments_by_event_slugs(
        &self,
        event_slugs: Vec<String>,
    ) -> anyhow::Result<Vec<InstrumentAny>> {
        let ts_init = self.clock.get_time_ns();

        let futures = event_slugs.into_iter().map(|slug| {
            let inner = Arc::clone(&self.inner);
            async move {
                match inner.get_gamma_events_by_slug(&slug).await {
                    Ok(events) => Some((slug, events)),
                    Err(e) => {

View on GitHub (pinned to 18893faf8b)

Solutions

1. Read the wrapped error {e} for the underlying cause (transport vs HTTP status vs retry exhaustion).
2. Confirm the slug values are correct and the Gamma endpoint is reachable.
3. Increase retry attempts/backoff or handle non-retryable Error variants explicitly before retrying.

for slug in &slugs { if slug.is_empty() { bail!("empty slug"); } }

match request_instruments_by_slugs_with_retry(slugs).await {
    Ok(instruments) => instruments,
    Err(e) => { error!("gamma instruments fetch failed after retries: {e}"); Vec::new() }
}

When it happens

Trigger: Calling request_instruments_by_slugs_with_retry when every retry fails — e.g. persistent transport errors, non-retryable HTTP errors, or the retry policy exhausting its attempts against GET /events?slug=.

Common situations: Gamma API outage, rate limiting beyond the retry budget, invalid slugs causing repeated HTTP errors, or network/proxy misconfiguration in the deployment environment.

Understand the failure class

Background: "API request failed": what wrapped HTTP errors from external APIs mean and how to find the real cause — this error's family across 29 libraries.

Related errors

• Failed to fetch order status: {e}
• {e}
• Modify order failed: {e}
• Either client_order_id or venue_order_id is required
• Failed to connect after {max_attempts} attempts

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/6d35d0297fb13075. Report an issue: GitHub.