Guardrail Policy Reference
A guardrail bundles a set of policies, each backed by AWS Bedrock Guardrails. Each policy is optional, but a guardrail must enforce at least one. This page documents each policy type’s configuration fields, available actions, direction settings, and regional availability.
Common settings
Two settings recur across policies:
-
Action: what the policy does when it matches.
Nonedetects and records the match in the trace without intervening.Blockstops the request and returns the configured blocked message. The sensitive-information policy addsAnonymize. -
Direction: most policies evaluate input, output, or both, and you set the action per direction. Some policies are fixed to one direction (noted below).
| Feature availability varies by AWS region. Choose a region that supports the policies you need, and see the AWS Bedrock Guardrails documentation for exhaustive behavior and regional support. |
Content filters
Classify prompts and responses against harmful-content categories and block or detect them per category.
| Field | Description |
|---|---|
Categories |
|
Strength |
Per category and direction. Sets the confidence cutoff for a match: |
Action |
Per category and direction: |
Modality |
|
Word filters
Block or detect exact words and phrases.
| Field | Description |
|---|---|
Custom words |
Your own list of words and phrases to match. |
Managed lists |
Platform-managed lists. |
Action |
Per direction (input and output): |
Denied topics
Block content by meaning rather than exact words, so the policy catches paraphrases and misspellings. A policy holds up to 30 topics.
| Field | Description |
|---|---|
Name |
Topic name, 1 to 100 characters. |
Definition |
What the topic covers, up to 1000 characters. The definition drives the semantic match, so write it as a clear, self-contained statement. Keep example phrases and negations out of the definition; put concrete examples in the Examples field instead, which improves accuracy. |
Examples |
Up to five example phrases, each up to 100 characters, that match the topic. |
Action |
Per direction (input and output): |
Sensitive information
Detect personally identifiable information (PII) by built-in entity type or by your own regular expressions, then detect, block, or anonymize it.
| Field | Description |
|---|---|
Entities |
Built-in entity types. Each entity has a per-direction action. |
Regexes |
Custom patterns. Each rule has a name (1 to 100 characters), an RE2 pattern (1 to 500 characters; lookaround is not supported), an optional description, and a per-direction action. |
Action |
Per direction (input and output): |
The built-in entity types are: ADDRESS, AGE, NAME, EMAIL, PHONE, USERNAME, PASSWORD, DRIVER_ID, LICENSE_PLATE, VEHICLE_IDENTIFICATION_NUMBER, CREDIT_DEBIT_CARD_CVV, CREDIT_DEBIT_CARD_EXPIRY, CREDIT_DEBIT_CARD_NUMBER, PIN, INTERNATIONAL_BANK_ACCOUNT_NUMBER, SWIFT_CODE, IP_ADDRESS, MAC_ADDRESS, URL, AWS_ACCESS_KEY, AWS_SECRET_KEY, US_BANK_ACCOUNT_NUMBER, US_BANK_ROUTING_NUMBER, US_INDIVIDUAL_TAX_IDENTIFICATION_NUMBER, US_PASSPORT_NUMBER, US_SOCIAL_SECURITY_NUMBER, CA_HEALTH_NUMBER, CA_SOCIAL_INSURANCE_NUMBER, UK_NATIONAL_HEALTH_SERVICE_NUMBER, UK_NATIONAL_INSURANCE_NUMBER, and UK_UNIQUE_TAXPAYER_REFERENCE_NUMBER.
Contextual grounding
For retrieval-augmented generation (RAG) applications, check model output against a source and the user’s query. This policy evaluates output only and has two independent sub-filters.
| Sub-filter | Description |
|---|---|
Grounding |
Checks that the response is factually grounded in the provided source. |
Relevance |
Checks that the response is relevant to the user’s query. |
Each sub-filter has its own enable toggle, a threshold between 0.0 and 0.99, and an action. The action fires when the response scores below the threshold, so higher thresholds are stricter. The action is None (detect) or Block.
Automated reasoning
Mathematically verify model output against formal Bedrock Automated Reasoning policies. This policy is detect-only: it never blocks, and its findings appear in the trace.
| Field | Description |
|---|---|
Policy ARNs |
One or two Bedrock Automated Reasoning policy Amazon Resource Names (ARNs) to attach. Each ARN must point at a specific numeric version (for example, ending in |
Confidence threshold |
A value between |