> ## 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.

# UUID identifiers

> Opt-in recognition of canonical UUIDs with exact source ranges.

<Note>
  UUID detection is available in Core 0.4.0 or newer and remains opt-in.
</Note>

UUIDs often identify records, requests or public resources. A UUID-shaped value
is not inherently personal or secret, so UUID scanning is disabled by default.
Enable it explicitly when those identifiers belong in your privacy policy.

```python theme={null}
from datafog_core import scan_and_transform

result = scan_and_transform("Customer 550e8400-e29b-41d4-a716-446655440000", {
    "scan": {"detect_uuid": True},
    "transform": {"default": {"strategy": "redact"}, "entities": ["UUID"]},
})
assert result.text == "Customer [UUID]"
```

Node and browser/WASM use the same JSON configuration with `detect_uuid: true`
and `scanAndTransform`. For Rust, use
`ScanConfig::new().with_uuid_detection(true)`. The option is independent of
locale, applies equally to text and structured scans, and must be a boolean.
Selecting `UUID` for transformation does not activate detection. Explicit UUID
findings can be transformed without any scan configuration.

## Accepted syntax

The detector recognizes the canonical `8-4-4-4-12` ASCII hex-and-hyphen form,
with version nibble 1–8 and IETF variant nibble `8`, `9`, `a` or `b`. Uppercase,
lowercase and mixed-case hex are accepted and preserved. The format and bit
positions follow [RFC 9562 sections 4.1–4.2](https://www.rfc-editor.org/rfc/rfc9562.html#section-4).

The policy excludes compact 32-character forms, other variants, unknown versions,
and the Nil/Max sentinel UUIDs. Braces and a `urn:uuid:` prefix may surround a
match but are not part of it. An immediately adjacent ASCII letter, digit,
underscore or hyphen prevents a match, so longer identifiers cannot yield a
UUID prefix. Unicode text and punctuation can delimit a match.

Recognition does not establish uniqueness, ownership, a valid timestamp or
sensitivity. No UUID generation, registry lookup or network access occurs.

## Findings and transformations

The label is `UUID`, detector name `datafog-core/uuid`, and version is the current
Core crate version. Confidence is absent. Source casing and exact byte/code-point
ranges are preserved; JavaScript bindings also return slice-compatible UTF-16
ranges. Structured findings use string-local ranges and JSON Pointer paths.

All existing transformation strategies, entity selection, overrides, and exact
or full-match regex allowlists work. Exact allowlists compare original casing.
Redaction uses `[UUID]`; masks cover all 36 source characters, including hyphens.
Provider-backed operations remain unsupported in browser/WASM. Generic scan
findings are retained; transformation overlap resolution is unchanged.