tracer-cloud--opensre/docs/guardrails

Guardrails: Sensitive Information Protection

Guardrails intercepts content before every LLM call and applies configurable rules to detect, redact, block, or audit sensitive information.

Quick start

# Generate a starter config with common patterns
opensre guardrails init

# Test it against sample text
opensre guardrails test "my key is AKIAIOSFODNN7EXAMPLE"

# View configured rules
opensre guardrails rules

How it works

1. Rules are loaded from ~/.opensre/guardrails.yml on first LLM call
2. Before every LLM API request, all message content is scanned against the rules
3. Depending on the rule action:
   • redact: matched text is replaced with [REDACTED:<rule_name>]
   • block: the request is rejected with a GuardrailBlockedError
   • audit: the match is logged but text passes through unchanged
4. All matches are written to ~/.opensre/guardrail_audit.jsonl

If no guardrails.yml exists, all content passes through unchanged with zero overhead.

Configuration

The config file lives at ~/.opensre/guardrails.yml. Each rule can use regex patterns, keyword lists, or both.

rules:
  - name: aws_access_key
    description: "AWS access key IDs"
    action: redact
    patterns:
      - "(?:AKIA|ASIA)[A-Z0-9]{16}"

  - name: credit_card
    description: "Credit card numbers"
    action: block
    patterns:
      - "\\b\\d{4}[- ]?\\d{4}[- ]?\\d{4}[- ]?\\d{4}\\b"

  - name: internal_domains
    description: "Internal hostnames that should not leak"
    action: audit
    keywords:
      - "prod-db.internal.corp"
      - "staging.internal.corp"

  - name: pii_fields
    description: "Common PII field names"
    action: redact
    keywords:
      - "social_security"
      - "date_of_birth"
    replacement: "[PII_REDACTED]"

Rule fields

Field	Required	Description
name	yes	Unique identifier for the rule
action	no	redact, block, or audit (default: audit)
patterns	no*	List of regex patterns (case-insensitive)
keywords	no*	List of literal keywords (case-insensitive)
description	no	Human-readable description
replacement	no	Custom replacement text (default: [REDACTED:<name>])
enabled	no	Set to false to disable without removing (default: true)

*At least one of patterns or keywords is required.

CLI commands

opensre guardrails init

Creates a starter ~/.opensre/guardrails.yml with common patterns for AWS keys, credit cards, private keys, and API tokens. Does not overwrite an existing config.

opensre guardrails test "text"

Dry-run: scans the provided text against all rules and shows what would be matched, redacted, or blocked.

$ opensre guardrails test "key=AKIAIOSFODNN7EXAMPLE"
  [REDACT] aws_access_key: matched 'AKIAIOSFODNN7EXAMPLE'

  Redacted output: key=[REDACTED:aws_access_key]

opensre guardrails rules

Lists all configured rules with their action and status.

opensre guardrails audit

Shows recent entries from the audit log at ~/.opensre/guardrail_audit.jsonl.

Health check

opensre health shows the current guardrails status:

CLI
  environment: development
  integration store: ~/.opensre/integrations.json
  guardrails: 5 rules active (~/.opensre/guardrails.yml)

Coverage

Guardrails protect all LLM call paths:

• Custom Anthropic client (LLMClient.invoke)
• OpenAI-compatible client (OpenAILLMClient.invoke)
• Structured output calls (delegated to base client)
• Interactive shell and investigation chat calls
• Alert extraction prompts
• Root cause diagnosis prompts
• Action planning prompts

Common patterns

Here are useful patterns you can add to your config:

# Email addresses
- name: email
  action: redact
  patterns:
    - "[a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\\.[a-zA-Z]{2,}"

# IPv4 addresses
- name: ipv4
  action: audit
  patterns:
    - "\\b\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\b"

# GitHub personal access tokens
- name: github_pat
  action: redact
  patterns:
    - "ghp_[a-zA-Z0-9]{36}"
    - "github_pat_[a-zA-Z0-9]{22}_[a-zA-Z0-9]{59}"

# Slack webhook URLs
- name: slack_webhook
  action: redact
  patterns:
    - "https://hooks\\.slack\\.com/services/T[A-Z0-9]+/B[A-Z0-9]+/[a-zA-Z0-9]+"

# JWT tokens
- name: jwt
  action: redact
  patterns:
    - "eyJ[A-Za-z0-9_-]+\\.eyJ[A-Za-z0-9_-]+\\.[A-Za-z0-9_-]+"