> ## Documentation Index
> Fetch the complete documentation index at: https://tero-0926be64-video-walkthrough.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Master Catalog

> The catalog context behind issues and policies

The Master Catalog is Tero's maintained context for the telemetry estate.

Use catalog data to understand an issue before you approve a policy: it links findings to services, log events, ownership, volume, cost, compliance exposure, and related runtime state.

## Current catalog surfaces

Tero exposes catalog context through Services and Log events.

<CardGroup cols={2}>
  <Card title="Services" icon="box" href="/master-catalog/services">
    Service-level ownership, status, open issues, log volume, cost, and related log events.
  </Card>

  <Card title="Log events" icon="file-lines" href="/master-catalog/log-events">
    Grouped log patterns with service, severity, event rate, volume, cost, policies, and issues.
  </Card>
</CardGroup>

Tero also presents catalog-backed lanes:

* **Cost** shows service-level log cost and recoverable savings.
* **Compliance** shows affected services, exposed fields, and affected log events.
* **Checks** shows detector inventory and related issues.
* **Log ingestion** shows Datadog ingestion analysis, index breakdown, migration candidates, and projected savings.

## How catalog context helps review

Before approving a policy you need the owning service, the affected log event pattern, the volume and cost involved, the issue or check that produced the recommendation, and any policy or runtime state that already exists. The catalog supplies those facts across Tero.

Issues use catalog context to explain findings, and policies link back to issues and services. Edge instances and provider surfaces show whether approved policies run.

## Metrics and traces

Tero is telemetry control, but these docs cover the log-oriented surfaces: services, log events, checks, issues, policies, log ingestion, cost, compliance, and Edge runtime state.

Use the Metrics or Trace Spans pages only when your Tero account exposes those surfaces.

## Related pages

* [Services](/master-catalog/services)
* [Log events](/master-catalog/log-events)
* [Issues](/issues/overview)
* [Policies](/policies)