# AI Harness Observability

Trace model calls, tool use, failures, cost, and safety signals.

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Canonical: /harness/observability/
Source: web/src/data/harness-markdown.ts
Format: Markdown for agents
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Production agents need operational visibility.

Capture enough telemetry to debug behavior without logging sensitive data.

## Useful Signals

- Agent name and version.
- Model and provider.
- Tool calls and outcomes.
- Token and cost estimates.
- Latency by model and tool.
- Safety filters and refusal decisions.
- Correlation IDs across PURISTA service calls.