nautechsystems/nautilus_trader · error · anyhow::Error

Failed to create HTTP client: {e}

Error message

Failed to create HTTP client: {e}

What it means

The authenticated branch of the data-client factory: building the underlying HTTP stack (AxHttpClient::with_credentials -> HttpClient::new with headers, rate-limiter quotas, timeout and optional proxy) returned Err, re-wrapped as AxHttpError::NetworkError("Failed to create HTTP client: ...") and surfaced with this anyhow context. Construction-time failures are local, not venue responses: typically an invalid proxy_url, a TLS/connector initialization failure, or a misbuilt client runtime.

Source

Thrown at crates/adapters/architect_ax/src/factories.rs:118

        let client_id = ClientId::from(name);

        let http_client = if ax_config.has_api_credentials() {
            let credential =
                Credential::resolve(ax_config.api_key.clone(), ax_config.api_secret.clone())
                    .ok_or_else(|| anyhow::anyhow!("API credentials not configured"))?;

            AxHttpClient::with_credentials(
                credential.api_key().to_string(),
                credential.api_secret().to_string(),
                Some(ax_config.http_base_url()),
                None, // orders_base_url
                ax_config.http_timeout_secs,
                ax_config.max_retries,
                ax_config.retry_delay_initial_ms,
                ax_config.retry_delay_max_ms,
                ax_config.proxy_url.clone(),
            )
            .map_err(|e| anyhow::anyhow!("Failed to create HTTP client: {e}"))?
        } else {
            AxHttpClient::new(
                Some(ax_config.http_base_url()),
                None, // orders_base_url
                ax_config.http_timeout_secs,
                ax_config.max_retries,
                ax_config.retry_delay_initial_ms,
                ax_config.retry_delay_max_ms,
                ax_config.proxy_url.clone(),
            )
            .map_err(|e| anyhow::anyhow!("Failed to create HTTP client: {e}"))?
        };

        let ws_url = ax_config.ws_public_url();

        // Token set during connect
        let ws_client = AxMdWebSocketClient::without_auth(
            ws_url,

View on GitHub (pinned to a4b06ed870)

Solutions

1. Check the inner {e}: 'proxy' errors -> fix/remove proxy_url in the config; TLS errors -> check build features and CA store
2. Retry with proxy_url: None to isolate whether the proxy is the cause
3. Validate the proxy URL parses (reqwest::Proxy::all) before passing it into config
4. Confirm the same config works in a plain environment (no proxy env vars like HTTPS_PROXY leaking in)

Example fix

// before
let cfg = AxDataClientConfig::builder()
    .proxy_url(Some("localhost:8080".into())) // missing scheme -> client build fails
    .build()?;
// after
let cfg = AxDataClientConfig::builder()
    .proxy_url(Some("http://localhost:8080".into()))
    .build()?;

// Validate the proxy URL before handing it to the config
if let Some(proxy) = &config.proxy_url {
    reqwest::Proxy::all(proxy.as_str())
        .with_context(|| format!("invalid proxy_url: {proxy}"))?;
}

match AxDataClientFactory.create(...) {
    Err(e) if e.to_string().contains("Failed to create HTTP client") => {
        log::error!("local HTTP stack init failed: {e:#}"); // do not retry unchanged config
        Err(e)
    }
    r => r,
}

When it happens

Trigger: AxDataClientConfig with proxy_url set to a malformed URL or unreachable proxy scheme; TLS backend problems in the build (missing rustls/native-tls features); exotic runtime configurations where the HTTP connector cannot initialize. Happens with valid credentials - it fails before any request is sent.

Common situations: Corporate-proxy deployments where proxy_url was typo'd (missing scheme, bad port); hardened containers missing CA bundles; feature-flag mismatches after editing the crate's Cargo features.

Related errors

• Invalid config type for AxDataClientFactory. Expected AxData
• Invalid config type for AxExecutionClientFactory. Expected A
• Authentication failed: {e}
• Invalid order side: {e}
• Instrument {instrument_id} not found in cache

AI-assisted analysis of nautechsystems/nautilus_trader@a4b06ed870 (2026-08-16). Data as JSON: /api/errors/a5919561e965bbe5. Report an issue: GitHub.