Keyword Filter

Matches specific keywords or regex patterns in user input and performs an action (block, sanitize, log).

The Keyword Filter guard scans messages for specific words, phrases, or regular expressions. It supports three modes:

• block: Rejects the request if a keyword is found.
• sanitize: Replaces found keywords with the configured replacement text.
• log: Only logs the finding without altering the request or blocking it.

Matching can be case-sensitive or insensitive, and you can require matching ‘all’ keywords instead of ‘any’.

Configuration

Field	Type	Default	Description
keywords	array	[]	List of keywords or regular expressions to match.
match_mode	string	"any"	Whether to trigger on ‘any’ matched keyword or require ‘all’ to match.
case_sensitive	boolean	False	Whether the matching should be case-sensitive.
action	string	"block"	Action to take when triggered (‘block’, ‘sanitize’, ‘log’).
replacement	string	"[REDACTED]"	Text to replace matched keywords with when action is ‘sanitize’.
use_regex	boolean	False	Whether the keywords should be treated as regular expressions.
scan_input_only	boolean	False	When True, keywords are only matched against the request input. Stream output scanning (stream_blocks) is skipped. Use this for broad patterns that would cause false positives on model output.

Examples

# Block Specific Words
type: keyword_filter
config:
  keywords:
  - secret
  - confidential
  match_mode: any
  action: block

# Sanitize API Keys
type: keyword_filter
config:
  keywords:
  - sk-[a-zA-Z0-9]{48}
  use_regex: true
  action: sanitize
  replacement: '[API_KEY_REDACTED]'