> ## Documentation Index
> Fetch the complete documentation index at: https://docs.braintrust.dev/llms.txt
> Use this file to discover all available pages before exploring further.

# CloudFront 403 errors during evaluator invocation

> [!NOTE]
>
> **Applies to:**
>
> * Plan - Enterprise
> * Deployment - Self-hosted (self-hosted data plane)
> *
> * Use case - Evaluators with scorers processing large token counts that exceed 60-second response times

## Summary

**Issue:** Evaluator invocations fail with `403 Forbidden` errors from CloudFront when processing large inputs. Evaluations hang indefinitely on rows with high token counts before failing.

**Cause:** CloudFront's `origin_read_timeout` is set to 60 seconds, causing requests to fail when scorers take longer to process large payloads.

**Resolution:** Reduce input size to scorers or configure CloudFront timeout settings in your Terraform deployment.

## Resolution Steps

### Immediate workaround: Reduce scorer input size

#### Step 1: Limit tokens sent to scorers

Reduce the amount of data sent to individual scorers, especially for informational scorers that are not critical to evaluation results.

#### Step 2: Split evaluations into smaller batches

Break large evaluations into multiple smaller runs to avoid timeout thresholds.


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