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

# Configure transformations

> Select entities, override strategies, add allowlists, and keep scan settings separate.

Every transformation configuration requires a `default` strategy.

```json theme={null}
{
  "default": { "strategy": "redact" }
}
```

`scan_and_transform` wraps this configuration under `transform` and keeps
detection settings under `scan`:

```json theme={null}
{
  "scan": { "locale": "en-US" },
  "transform": {
    "default": { "strategy": "redact" }
  }
}
```

## Select entity types

Omitting `entities` selects all supplied findings. A non-empty list selects only
exact, case-sensitive entity names.

```json theme={null}
{
  "default": { "strategy": "redact" },
  "entities": ["EMAIL", "PHONE"]
}
```

An empty `entities` list is invalid.

## Override a strategy

Overrides are exact and case-sensitive. Findings without an override use the
default strategy.

```json theme={null}
{
  "default": { "strategy": "redact" },
  "overrides": {
    "PHONE": {
      "strategy": "mask",
      "reveal": { "direction": "last", "count": 4 }
    }
  }
}
```

## Exempt exact values

Exact allowlists are scoped to an entity type and compare exact Unicode values
without normalization.

```json theme={null}
{
  "default": { "strategy": "redact" },
  "allow": {
    "exact": {
      "EMAIL": ["support@example.com"]
    }
  }
}
```

## Exempt values with regular expressions

Regex allowlist patterns must match the full finding value. Matching is
case-sensitive by default.

```json theme={null}
{
  "default": { "strategy": "redact" },
  "allow": {
    "regex": {
      "EMAIL": [
        { "pattern": ".+@example\\.org" },
        { "pattern": ".+@example\\.com", "case_sensitive": false }
      ]
    }
  }
}
```

## Evaluation order

DataFog Core processes a request in this order:

1. Validate the complete configuration.
2. Select entity types.
3. Apply exact and regex allowlists.
4. Resolve duplicates and overlaps.
5. Choose the per-entity override or default strategy.
6. Transform selected findings in document order.

Valid configuration for an unselected entity remains dormant. Invalid fields
are rejected even when their entity is not selected.

## Strict input

Unknown fields and explicit `null` values are rejected. Empty structural maps
are treated as omission, but empty semantic values such as an empty entity
selection, key reference, or token reference are invalid.