> ## Documentation Index > Fetch the complete documentation index at: https://openrouter.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # ContentFilterBuiltinEntry A builtin content filter entry. Builtin filters include PII detectors, API-key and secret detectors, and the regex-based prompt injection detector. ## Fields | Field | Type | Required | Description | Example | | ------------ | --------------------------------------------------------------------------------------------- | -------------------- | --------------------------------------------------------------------------------------------------------------------------------- | ---------------------- | | `action` | [components.ContentFilterBuiltinAction](../components/contentfilterbuiltinaction.mdx) | :heavy\_check\_mark: | Action taken when the builtin filter triggers | block | | `label` | *Optional\[str]* | :heavy\_minus\_sign: | Read-only, system-assigned redaction placeholder derived from the slug (e.g. "\[EMAIL]", "\[PHONE]"). Not settable by the caller. | \[EMAIL] | | `scan_scope` | [Optional\[components.PromptInjectionScanScope\]](../components/promptinjectionscanscope.mdx) | :heavy\_minus\_sign: | Which message roles to scan for prompt injection. Only applies to the regex-prompt-injection builtin. Defaults to all\_messages. | user\_only | | `slug` | [components.ContentFilterBuiltinSlug](../components/contentfilterbuiltinslug.mdx) | :heavy\_check\_mark: | The builtin filter identifier | regex-prompt-injection |