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

# Guardrails AI

> PII detection and protection validator for the Guardrails AI framework

The `guardrails-blindfold` package integrates Blindfold with [Guardrails AI](https://guardrailsai.com), letting you add PII protection to any Guard with one line. Detect and fix PII in LLM outputs automatically.

## Installation

```bash theme={null}
pip install guardrails-blindfold
```

Set your API key:

```bash theme={null}
export BLINDFOLD_API_KEY=your-api-key
```

Get a free API key at [app.blindfold.dev](https://app.blindfold.dev).

## Quick Start

```python theme={null}
from guardrails import Guard
from guardrails_blindfold import BlindfoldPII

guard = Guard().use(BlindfoldPII(on_fail="fix"))

result = guard.validate("Contact John Doe at john@example.com")
print(result.validated_output)
# → "Contact <Person_1> at <Email Address_1>"
```

## Parameters

| Parameter         | Type    | Default      | Description                               |
| ----------------- | ------- | ------------ | ----------------------------------------- |
| `policy`          | `str`   | `"basic"`    | Detection policy                          |
| `pii_method`      | `str`   | `"tokenize"` | How to fix detected PII                   |
| `region`          | `str`   | `None`       | `"eu"` or `"us"` for data residency       |
| `entities`        | `list`  | `None`       | Specific entity types to detect           |
| `score_threshold` | `float` | `None`       | Confidence threshold (0.0–1.0)            |
| `api_key`         | `str`   | `None`       | Falls back to `BLINDFOLD_API_KEY` env var |
| `on_fail`         | `str`   | `None`       | Guardrails failure action                 |

### Policies

| Policy     | Entities                                      | Best For               |
| ---------- | --------------------------------------------- | ---------------------- |
| `basic`    | Names, emails, phones, locations              | General PII protection |
| `gdpr_eu`  | EU-specific: IBANs, addresses, dates of birth | GDPR compliance        |
| `hipaa_us` | PHI: SSNs, MRNs, medical terms                | HIPAA compliance       |
| `pci_dss`  | Card numbers, CVVs, expiry dates              | PCI DSS compliance     |
| `strict`   | All entity types, lower threshold             | Maximum detection      |

See [Policies](/essentials/policies) for details.

### PII Methods

The `pii_method` parameter controls how detected PII is fixed when `on_fail="fix"`:

| Method       | Output                            | Reversible     |
| ------------ | --------------------------------- | -------------- |
| `tokenize`   | `<Person_1>`, `<Email Address_1>` | Yes            |
| `redact`     | PII removed entirely              | No             |
| `mask`       | `J****oe`, `j****om`              | No             |
| `hash`       | `HASH_abc123`                     | No             |
| `synthesize` | `Jane Smith`, `jane@example.org`  | No             |
| `encrypt`    | AES-256 encrypted value           | Yes (with key) |

## Usage Examples

### GDPR Compliance with EU Region

```python theme={null}
guard = Guard().use(
    BlindfoldPII(
        policy="gdpr_eu",
        region="eu",
        on_fail="fix",
    )
)

result = guard.validate("Hans Mueller, hans.mueller@example.de, IBAN DE89370400440532013000")
print(result.validated_output)
# → "<Person_1>, <Email Address_1>, IBAN <IBAN_1>"
```

### HIPAA — Redact PHI

```python theme={null}
guard = Guard().use(
    BlindfoldPII(
        policy="hipaa_us",
        pii_method="redact",
        region="us",
        on_fail="fix",
    )
)

result = guard.validate("Patient Sarah Jones, SSN 123-45-6789, MRN 4567890")
print(result.validated_output)
# → PHI redacted from output
```

### Block Output if PII Detected

Use `on_fail="exception"` to raise an error instead of fixing:

```python theme={null}
from guardrails.errors import ValidationError

guard = Guard().use(
    BlindfoldPII(policy="strict", on_fail="exception")
)

try:
    result = guard.validate("Email john@example.com")
except ValidationError as e:
    print("PII detected — output blocked")
```

### Detect Specific Entity Types

```python theme={null}
guard = Guard().use(
    BlindfoldPII(
        entities=["Email Address", "Phone Number", "Credit Card Number"],
        on_fail="fix",
    )
)
```

### Chain with Other Validators

Blindfold can be combined with any other Guardrails validator:

```python theme={null}
guard = Guard().use(
    BlindfoldPII(policy="strict", on_fail="fix"),
).use(
    AnotherValidator(on_fail="exception"),
)
```

### Protect LLM Output in a Chain

```python theme={null}
from guardrails import Guard
from guardrails_blindfold import BlindfoldPII
from openai import OpenAI

client = OpenAI()
guard = Guard().use(BlindfoldPII(policy="gdpr_eu", on_fail="fix"))

response = client.chat.completions.create(
    model="gpt-4o-mini",
    messages=[{"role": "user", "content": "Write a sample customer profile"}],
)

# Validate and protect PII in the LLM output
result = guard.validate(response.choices[0].message.content)
print(result.validated_output)  # PII tokenized
```

## On-Fail Actions

Guardrails supports several failure handling strategies:

| Action      | Behavior                                                           |
| ----------- | ------------------------------------------------------------------ |
| `fix`       | Replace PII with the protected version (tokenized, redacted, etc.) |
| `exception` | Raise `ValidationError` — blocks the output entirely               |
| `noop`      | Log the failure but return the original output unchanged           |
| `reask`     | Re-prompt the LLM to regenerate without PII                        |

## Data Residency

Use the `region` parameter to ensure PII is processed in a specific jurisdiction:

| Region | Endpoint               | Location           |
| ------ | ---------------------- | ------------------ |
| `eu`   | `eu-api.blindfold.dev` | Frankfurt, Germany |
| `us`   | `us-api.blindfold.dev` | Virginia, US       |

See [Regions](/essentials/regions) for details.

## Links

<CardGroup cols={2}>
  <Card title="PyPI Package" icon="python" href="https://pypi.org/project/guardrails-blindfold/">
    Install from PyPI
  </Card>

  <Card title="GitHub" icon="github" href="https://github.com/blindfold-dev/guardrails-blindfold">
    Source code and issues
  </Card>

  <Card title="Guardrails AI Docs" icon="book" href="https://docs.guardrailsai.com">
    Guardrails AI documentation
  </Card>

  <Card title="Cookbook Examples" icon="code" href="https://github.com/blindfold-dev/blindfold-cookbook">
    Working integration examples
  </Card>
</CardGroup>