BoundaryML/baml · error · ExposedError

ExposedError::ClientHttpError { client_name, message, status

Error message

ExposedError::ClientHttpError { client_name, message, status_code, detailed_message, raw_response }

What it means

For any other LLMFailure error code, result_with_constraints_content converts it to ExposedError::ClientHttpError with the client name, message, status code, detailed message and raw response. This is the generic HTTP-level failure path from the LLM provider.

Source

Thrown at engine/baml-runtime/src/types/response.rs:138

                Ok(val) => Ok(val),
                Err(err) => Err(anyhow::anyhow!(self.format_last_error_with_details(err))),
            })
        else {
            // If we don't have a parsed result, check if we have an LLMFailure
            return match self.llm_response() {
                    LLMResponse::LLMFailure(err) => {
                        // Convert LLMFailure to appropriate error type
                        match &err.code {
                            crate::internal::llm_client::ErrorCode::Timeout => {
                                Err(anyhow::anyhow!(crate::errors::ExposedError::TimeoutError {
                                    client_name: err.client.clone(),
                                    message: err.message.clone(),
                                }))
                            }
                            crate::internal::llm_client::ErrorCode::Other(2) => {
                                Err(anyhow::anyhow!(err.message.clone()))
                            }
                            _ => Err(anyhow::anyhow!(
                                crate::errors::ExposedError::ClientHttpError {
                                    client_name: err.client.clone(),
                                    message: err.message.clone(),
                                    status_code: err.code.clone(),
                                    detailed_message: err.message.clone(),
                                    raw_response: err.raw_response.clone(),
                                }
                            )),
                        }
                    }
                    LLMResponse::UserFailure(message) => {
                        Err(anyhow::anyhow!("User Failure: {message}.\nPlease report this error to our team with BAML_LOG=info enabled so we can catch this error earlier and improve your development experience."))
                    }
                    LLMResponse::InternalFailure(message) => {
                        Err(anyhow::anyhow!("Internal Failure: {message}.\nThis should not happen - please report this error to our team with BAML_LOG=info enabled so we can catch this error earlier and improve your development experience."))
                    }
                    LLMResponse::Cancelled(message) => {
                        Err(anyhow::anyhow!(crate::errors::ExposedError::AbortError {

View on GitHub (pinned to bd85ce9dee)

Solutions

1. Inspect status_code and raw_response in the error to identify the provider issue.
2. Fix credentials/API key configuration for 401/403 errors.
3. Add retry with backoff for 429/5xx, or configure BAML's retry strategy.
4. Verify model name and provider base_url in the client config.

Example fix

// before
let v = chain.content()?; // ClientHttpError 429 surfaces

// after
match chain.content() {
    Ok(v) => Ok(v),
    Err(e) if e.to_string().contains("429") => retry_with_backoff(),
    Err(e) => Err(e),
}

match chain.content() {
    Ok(v) => Ok(v),
    Err(e) if is_http_status(&e, &[429, 500, 502, 503]) => retry_with_backoff(),
    Err(e) => Err(e),
}

When it happens

Trigger: Reading the result of a chain whose LLM call failed with a non-timeout, non-Other(2) error code — typically HTTP error statuses (401, 403, 429, 5xx) returned by the provider.

Common situations: Invalid or expired API keys (401), quota/rate limits (429), provider 5xx outages, wrong base URL or model name (404).

Understand the failure class

Background: "API error: {status}" and "HTTP 401/403/404/429/5xx" errors: non-2xx HTTP responses explained — this error's family across 27 libraries.

Related errors

• LLM client "{client_name}" failed with status code: {status_
• BamlError: BamlClientError: BamlClientHttpError: {message}
• Auth server returned {status}: {body}
• PostHog returned {status}
• network error fetching {url}: {source}

AI-assisted analysis of BoundaryML/baml@bd85ce9dee (2026-09-12). Data as JSON: /api/errors/b9ad69e2740bfc7a. Report an issue: GitHub.