> ## Documentation Index
> Fetch the complete documentation index at: https://neuraltrust-92b43583-develop.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Detectors

> Configure reusable detector instances and attach them to TrustGuard policies

A **detector** is a reusable, named instance you create from one entry in the
[detector catalog](/trustguard/detectors/overview), such as `prompt_guard`, plus
its settings. Settings can include thresholds, entity lists, and allow or deny
lists. You
create and edit detectors in the console's **Detectors** screen, and the same
detector can be referenced by many [policies](/trustguard/concepts/policies).

<Note>
  Detectors report what they find and their confidence. They do not decide whether
  to block, mask, or allow traffic. That
  decision lives on the [policy](/trustguard/concepts/policies) that uses the
  detector (its **Gates** and **Detectors** tabs). This separation lets you reuse
  one well-tuned detector across many policies with different enforcement.
</Note>

## What defines a detector

| Property     | Values                                                       | Meaning                                                                                                                                                                       |
| ------------ | ------------------------------------------------------------ | ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Type**     | one entry from the [catalog](/trustguard/detectors/overview) | The catalog detector, such as `prompt_guard` or `data_loss_prevention`. Its type is fixed after creation; its settings remain configurable. Sent to the API as `plugin_slug`. |
| **Name**     | free text                                                    | A label that distinguishes configured instances of the same detector type.                                                                                                    |
| **Settings** | type-specific                                                | Thresholds, entity lists, keyword or regular-expression lists, and other detector-specific values. The console renders and validates the form.                                |
| **Enabled**  | on / off                                                     | A disabled detector is skipped everywhere it's referenced.                                                                                                                    |

A detector does **not** carry a mode, a direction, or a protocol. Those belong
to the [policy](/trustguard/concepts/policies) rule that puts the detector to
work (the **Input** / **Output** phase). At request time, the collector must send
the matching `direction` on `/v1/evaluate`. [TrustGate](/integrations/trustgate)
sets it automatically; [application SDKs](/integrations/python-sdk) and other
collectors must set it themselves.

## Settings

Every catalog detector exposes its own settings schema (the catalog API,
`GET /v1/plugins`, returns each detector type and its fields). Examples:

* `prompt_guard`, `toxicity`: a `threshold` in `[0, 1]`.
* `data_loss_prevention`: which PII entities to detect or mask, plus custom
  keyword/regex rules.
* Moderation (`prompt_moderation`): keyword or regular-expression lists and
  NeuralTrust topic thresholds.

See each detector's full settings on its
[category page](/trustguard/detectors/overview).

## Mutable (transform-capable) detectors

Most detectors only read the payload. A **mutable** detector can rewrite it.
Currently, only [`data_loss_prevention`](/trustguard/detectors/data-loss-prevention)
which masks matched values in flight and populates `transformed_payload`.

Only a mutable detector can be used with the **Transform** action in a policy;
choosing Transform for any other detector is rejected when you save the policy.

## Putting a detector to work

Creating a detector doesn't run it. To evaluate traffic you reference the
detector from a [policy](/trustguard/concepts/policies):

1. Open a policy and select the **Detectors** tab.
2. Pick an **evaluation phase**: **Input** (prompt/request) or **Output**
   (completion/response).
3. Add a rule that selects the detector and an **action**: **Monitor**
   (record a finding only), **Block**, or **Transform** (mutable detectors).
4. Optionally add **conditions** so the rule only runs for certain consumers,
   models, collectors, protocols, sessions, directions, or tools.

Then attach the policy to a [collector](/trustguard/concepts/collectors) so its
traffic is evaluated.