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

# Observe & Control

> Inspect model calls, enforce organization rules, and route traffic without changing application code.

Once an AI feature reaches production, you need to understand what it is doing
and change its operating boundaries safely. **Observe & Control** brings those
tools together in the Opper platform.

## Observe what happened

<CardGroup cols={2}>
  <Card title="Traces" icon="list-tree" href="/control-plane/trace">
    Inspect the model call, nested tool calls, cost, latency, and rule activity behind a request.
  </Card>

  <Card title="Files" icon="folder-open" href="/build/multimodal/files">
    Manage files used as model inputs and generation outputs.
  </Card>
</CardGroup>

## Control what is allowed

[**Rules**](/control-plane/rules/overview) is the organization-level workspace
for the policies Opper enforces on model calls.

<CardGroup cols={2}>
  <Card title="Data retention" icon="database" href="/control-plane/rules/retention">
    Choose how long call content is stored, or enable Zero Data Retention.
  </Card>

  <Card title="Spend limits" icon="wallet" href="/control-plane/rules/spend">
    Set a monthly organization budget and optional project caps.
  </Card>

  <Card title="Model access" icon="scale-balanced" href="/control-plane/rules/model-access">
    Restrict the providers, regions, countries, and models your apps can use.
  </Card>

  <Card title="Checks" icon="shield" href="/control-plane/rules/checks">
    Score quality or flag, redact, and block content.
  </Card>
</CardGroup>

Route rules remain available for setting a default model or configuring response
caching:

<CardGroup cols={2}>
  <Card title="Route" icon="signs-post" href="/control-plane/route">
    Set a default model for an organization or project.
  </Card>
</CardGroup>

## How rules apply

Organization rules set the default for every project. Project overrides can
tighten that default, but cannot loosen it.

* Model-access rules intersect, so a model must be available at both levels.
* The shortest applicable retention period wins.
* Project spend caps must fit inside the organization budget.
* Checks can run across the organization or only on selected projects.

When trace storage is enabled, rule activity appears on the relevant
[trace](/control-plane/trace). In the playground, turn on **Project controls** to
test a call with its rules applied.