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

> Scans messages for regex patterns and rejects or redacts matches. Useful for filtering sensitive information like emails, phone numbers, or credit card numbers.

# Regex Detect

The Regex Detect plugin scans user and assistant messages for specified regex patterns and can either reject requests containing matches or redact the matched content.

## Features

* **Flexible Pattern Matching**: Configure multiple regex patterns with optional flags
* **Selective Scanning**: Choose to scan only the latest message or all messages in the conversation
* **Reject or Redact**: Either block requests containing sensitive data or automatically redact it
* **Custom Messages**: Define custom rejection messages for different patterns
* **Configurable Redaction**: Use static text or character repetition for redaction

## Use Cases

* Filter sensitive information (emails, phone numbers, credit cards)
* Enforce content policies by blocking specific patterns
* Automatically redact PII (Personally Identifiable Information)
* Prevent prompt injection attacks by detecting suspicious patterns

## Configuration Options

### `patterns` (required)

Array of pattern objects to scan for. Each pattern object contains:

* `regex` (string, required): The regular expression pattern to match
* `flags` (string, optional): Regex flags (e.g., 'gi' for global case-insensitive). Default: 'g'
* `rejectMessage` (string, optional): Custom message to return when this pattern is matched

### `scanAllMessages` (boolean)

* `true`: Scans all messages in the array
* `false`: Only scans the latest message
* Default: `false`

### `redactMatches` (boolean)

* `true`: Redacts matched patterns instead of rejecting the request
* `false`: Rejects the request if a match is found
* Default: `false`

### `redactionText` (string)

Text to replace redacted patterns with. Default: `[REDACTED]`

### `redactCharacters` (string)

If set, replaces each match with this character repeated to match the length of the original text. Overrides `redactionText` if both are set.

## Example Configurations

### Block Email Addresses

```json theme={null}
{
  "patterns": [
    {
      "regex": "\\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Z|a-z]{2,}\\b",
      "flags": "gi",
      "rejectMessage": "Email addresses are not allowed in requests"
    }
  ],
  "scanAllMessages": false,
  "redactMatches": false
}
```

### Redact Phone Numbers

```json theme={null}
{
  "patterns": [
    {
      "regex": "\\b\\d{3}[-.]?\\d{3}[-.]?\\d{4}\\b",
      "flags": "g"
    }
  ],
  "scanAllMessages": true,
  "redactMatches": true,
  "redactionText": "[PHONE]"
}
```

### Redact Credit Cards with Character Masking

```json theme={null}
{
  "patterns": [
    {
      "regex": "\\b\\d{4}[\\s-]?\\d{4}[\\s-]?\\d{4}[\\s-]?\\d{4}\\b",
      "flags": "g"
    }
  ],
  "scanAllMessages": true,
  "redactMatches": true,
  "redactCharacters": "*"
}
```

### Multiple Patterns

```json theme={null}
{
  "patterns": [
    {
      "regex": "\\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Z|a-z]{2,}\\b",
      "flags": "gi",
      "rejectMessage": "Email addresses are not allowed"
    },
    {
      "regex": "\\b\\d{3}-\\d{2}-\\d{4}\\b",
      "flags": "g",
      "rejectMessage": "Social Security Numbers are not allowed"
    }
  ],
  "scanAllMessages": false,
  "redactMatches": false
}
```

## Response Behavior

### When Rejecting (redactMatches: false)

* Returns `reject: true` with a rejection reason
* Uses custom `rejectMessage` if provided, otherwise a default message
* No messages are modified

### When Redacting (redactMatches: true)

* Returns modified messages array with redacted content
* Original request continues through the pipeline
* Debug logs indicate how many matches were redacted

## Common Regex Patterns

* **Email**: `\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\.[A-Z|a-z]{2,}\b`
* **US Phone**: `\b\d{3}[-.]?\d{3}[-.]?\d{4}\b`
* **Credit Card**: `\b\d{4}[\s-]?\d{4}[\s-]?\d{4}[\s-]?\d{4}\b`
* **SSN**: `\b\d{3}-\d{2}-\d{4}\b`
* **IP Address**: `\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b`
* **URL**: `https?://[^\s]+`

## Notes

* Patterns are tested in order; the first match determines the rejection message
* Invalid regex patterns are logged in debug output but don't fail the request
* The 'g' (global) flag is recommended for finding all matches
* When using `redactCharacters`, the replacement length always matches the original

***

## Configuration Schema

```json theme={null}
{
  "type": "object",
  "title": "Regex Detect Configuration",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "required": [
    "patterns"
  ],
  "properties": {
    "patterns": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "regex"
        ],
        "properties": {
          "flags": {
            "type": "string",
            "title": "Regex Flags",
            "default": "g",
            "description": "Optional regex flags (e.g., 'gi' for global case-insensitive)"
          },
          "regex": {
            "type": "string",
            "title": "Regular Expression",
            "description": "The regex pattern to match (e.g., \\b[A-Za-z0-9._%+-]+@[A-Za-z0-9.-]+\\.[A-Z|a-z]{2,}\\b for emails)"
          },
          "rejectMessage": {
            "type": "string",
            "title": "Custom Reject Message",
            "description": "Custom message to return when this pattern is matched"
          }
        }
      },
      "title": "Regex Patterns",
      "minItems": 1,
      "description": "List of regex patterns to scan for"
    },
    "redactMatches": {
      "type": "boolean",
      "title": "Redact Matches",
      "default": false,
      "description": "If true, redacts matched patterns instead of rejecting the request"
    },
    "redactionText": {
      "type": "string",
      "title": "Redaction Text",
      "default": "[REDACTED]",
      "description": "Text to replace redacted patterns with"
    },
    "scanAllMessages": {
      "type": "boolean",
      "title": "Scan All Messages",
      "default": false,
      "description": "If true, scans all messages. If false, only scans the latest message"
    },
    "redactCharacters": {
      "type": "string",
      "title": "Redact Characters",
      "description": "If set, replaces each match with this character repeated to match the original length. Overrides redactionText"
    }
  },
  "description": "Configuration for the Regex Detect plugin"
}
```