nautechsystems/nautilus_trader · error

debug_traceTransaction redirect rejected

Error message

debug_traceTransaction redirect rejected

What it means

`probe_call_trace` sends a test `debug_traceTransaction` request to check whether the endpoint accepts the configured `callTracer` request shape. When the underlying transport reports a client error containing "redirect response rejected", it is re-mapped to this specific error, distinguishing redirect rejection from other request failures.

Source

Thrown at crates/adapters/blockchain/src/rpc/http.rs:825

            "params": [
                B256::ZERO,
                {
                    "tracer": "callTracer",
                    "tracerConfig": {
                        "onlyTopCall": false,
                        "withLog": false,
                    },
                }
            ],
        });
        let bytes = self
            .send_rpc_request(request, Some(EXECUTION_RPC_TIMEOUT_SECS))
            .await
            .map_err(|e| match e {
                BlockchainRpcClientError::ClientError(message)
                    if message.contains("redirect response rejected") =>
                {
                    anyhow::anyhow!("debug_traceTransaction redirect rejected")
                }
                _ => anyhow::anyhow!("debug_traceTransaction request failed"),
            })?;
        let parsed =
            serde_json::from_slice::<RpcNodeHttpResponse<serde_json::Value>>(bytes.as_ref())
                .map_err(|_| anyhow::anyhow!("Failed to parse debug_traceTransaction response"))?;
        if parsed.jsonrpc.is_none()
            && let (Some(code), Some(_)) = (parsed.code, parsed.message)
        {
            return trace_probe_result(code);
        }

        if let Some(error) = parsed.error {
            return trace_probe_result(error.code);
        }
        anyhow::ensure!(
            parsed.result.is_some(),
            "debug_traceTransaction returned no result"

View on GitHub (pinned to 18893faf8b)

Solutions

1. Change the RPC URL to the final destination (usually https:// and the exact path) so no redirect occurs
2. Check whether a missing/expired API key causes the provider to redirect; add credentials to the URL/config
3. Test with `curl -i` on the configured URL to see the 3xx and its Location header
4. Remove trailing slashes or wrong paths that trigger canonical redirects

Example fix

// before: http URL that the gateway redirects to https
rpc_url = "http://rpc.provider.example/v3/mykey"
// after: use the final https URL directly
rpc_url = "https://rpc.provider.example/v3/mykey"

async fn no_redirect(url: &str) -> bool {
    reqwest::Client::new().post(url)
        .json(&serde_json::json!({"jsonrpc":"2.0","method":"eth_chainId","params":[],"id":1}))
        .send().await
        .map(|r| !r.status().is_redirection())
        .unwrap_or(false)
}
// also: curl -i $URL to inspect 3xx Location headers

match client.probe_call_trace().await {
    Ok(()) => Ok(()),
    Err(e) if e.to_string().contains("redirect rejected") => {
        Err(anyhow!("RPC URL redirects; use the final https URL directly: {e}"))
    }
    Err(e) => Err(e),
}

When it happens

Trigger: The HTTP client receives a redirect (3xx) from the RPC endpoint and refuses to follow it — typically the endpoint URL is behind a redirecting proxy, points at http:// when the server redirects to https://, or the provider redirects unauthenticated requests to a login/canonical URL.

Common situations: Configuring `http://host:8545` while the provider redirects to `https://`; trailing-slash or path redirects from a gateway; providers redirecting to an auth page when the API key is missing.

Understand the failure class

Background: "Invalid URL" / "URL cannot be empty": fix the malformed or missing URL behind request-construction failures — this error's family across 50 libraries.

Related errors

• {method} redirect rejected
• eth_call redirect rejected
• debug_traceTransaction RPC error {code}
• Failed to execute eth call RPC request: {e}
• Failed to parse eth call response: {e} Raw response: {previe

AI-assisted analysis of nautechsystems/nautilus_trader@18893faf8b (2026-09-08). Data as JSON: /api/errors/62fac52a1e2bd9df. Report an issue: GitHub.