# Crawler-facing error budgets

Canonical HTML: /atlas/error-budgets
Atlas version: atlas-2026-07-28-v1
Category: Quality, provenance, and observability

## Definition

An error budget defines how much failure and latency a crawl surface can tolerate before measurements or discovery become unreliable.

## How it works

Status errors, timeouts, stale imports, and high tail latency reduce effective coverage even when the average request succeeds.

## How to validate it

Report valid sample counts, error rate, p50 and p95 latency, newest observation age, and missing-field completeness per source class.

## Common failure

Displaying zero when no latency sample exists makes an unmeasured system look perfectly fast.

## Related topics

- [Measurement quality](/atlas/measurement-quality)
- [HTTP status semantics](/atlas/http-status)