Security Patterns
Comprehensive security patterns for building hardened applications. Each category has individual rule files in rules/ loaded on-demand.
Quick Reference
| Category | Rules | Impact | When to Use | |----------|-------|--------|-------------| | Authentication | 3 | CRITICAL | JWT tokens, OAuth 2.1/PKCE, RBAC/permissions | | Defense-in-Depth | 2 | CRITICAL | Multi-layer security, zero-trust architecture | | Input Validation | 3 | HIGH | Schema validation (Zod/Pydantic), output encoding, file uploads | | OWASP Top 10 | 2 | CRITICAL | Injection prevention, broken authentication fixes | | LLM Safety | 3 | HIGH | Prompt injection defense, output guardrails, content filtering | | PII Masking | 2 | HIGH | PII detection/redaction with Presidio, Langfuse, LLM Guard | | Scanning | 3 | HIGH | Dependency audit, SAST (Semgrep/Bandit), secret detection | | Advanced Guardrails | 2 | CRITICAL | NeMo/Guardrails AI validators, red-teaming, OWASP LLM |
Total: 20 rules across 8 categories
Quick Start
# Argon2id password hashing
from argon2 import PasswordHasher
ph = PasswordHasher()
password_hash = ph.hash(password)
ph.verify(password_hash, password)
# JWT access token (15-min expiry)
import jwt
from datetime import datetime, timedelta, timezone
payload = {
'sub': user_id, 'type': 'access',
'exp': datetime.now(timezone.utc) + timedelta(minutes=15),
}
token = jwt.encode(payload, SECRET_KEY, algorithm='HS256')
// Zod v4 schema validation
import { z } from 'zod';
const UserSchema = z.object({
email: z.string().email(),
name: z.string().min(2).max(100),
role: z.enum(['user', 'admin']).default('user'),
});
const result = UserSchema.safeParse(req.body);
# PII masking with Langfuse
import re
from langfuse import Langfuse
def mask_pii(data, **kwargs):
if isinstance(data, str):
data = re.sub(r'\b[\w.-]+@[\w.-]+\.\w+\b', '[REDACTED_EMAIL]', data)
data = re.sub(r'\b\d{3}-\d{2}-\d{4}\b', '[REDACTED_SSN]', data)
return data
langfuse = Langfuse(mask=mask_pii)
Authentication
Secure authentication with OAuth 2.1, Passkeys/WebAuthn, JWT tokens, and role-based access control.
| Rule | Description |
|------|-------------|
| auth-jwt.md | JWT creation, verification, expiry, refresh token rotation |
| auth-oauth.md | OAuth 2.1 with PKCE, DPoP, Passkeys/WebAuthn |
| auth-rbac.md | Role-based access control, permission decorators, MFA |
Key Decisions: Argon2id > bcrypt | Access tokens 15 min | PKCE required | Passkeys > TOTP > SMS
Defense-in-Depth
Multi-layer security architecture with no single point of failure.
| Rule | Description |
|------|-------------|
| defense-layers.md | 8-layer security architecture (edge to observability) |
| defense-zero-trust.md | Immutable request context, tenant isolation, audit logging |
Key Decisions: Immutable dataclass context | Query-level tenant filtering | No IDs in LLM prompts
Input Validation
Validate and sanitize all untrusted input using Zod v4 and Pydantic.
| Rule | Description |
|------|-------------|
| validation-input.md | Schema validation with Zod v4 and Pydantic, type coercion |
| validation-output.md | HTML sanitization, output encoding, XSS prevention |
| validation-schemas.md | Discriminated unions, file upload validation, URL allowlists |
Key Decisions: Allowlist over blocklist | Server-side always | Validate magic bytes not extensions
OWASP Top 10
Protection against the most critical web application security risks.
| Rule | Description |
|------|-------------|
| owasp-injection.md | SQL/command injection, parameterized queries, SSRF prevention |
| owasp-broken-auth.md | JWT algorithm confusion, CSRF protection, timing attacks |
Key Decisions: Parameterized queries only | Hardcode JWT algorithm | SameSite=Strict cookies
LLM Safety
Security patterns for LLM integrations including context separation and output validation.
| Rule | Description |
|------|-------------|
| llm-prompt-injection.md | Context separation, prompt auditing, forbidden patterns |
| llm-guardrails.md | Output validation pipeline: schema, grounding, safety, size |
| llm-content-filtering.md | Pre-LLM filtering, post-LLM attribution, three-phase pattern |
Key Decisions: IDs flow around LLM, never through | Attribution is deterministic | Audit every prompt
Context Separation (CRITICAL)
Sensitive IDs and data flow AROUND the LLM, never through it. The LLM sees only content — mapping back to entities happens deterministically after.
# CORRECT: IDs bypass the LLM
context = {"user_id": user_id, "tenant_id": tenant_id} # kept server-side
llm_input = f"Summarize this document:\n{doc_text}" # no IDs in prompt
llm_output = call_llm(llm_input)
result = {"summary": llm_output, **context} # IDs reattached after
Output Validation Pipeline
Every LLM response MUST pass a 4-stage guardrail pipeline before reaching the user:
def validate_llm_output(raw_output: str, schema, sources: list[str]) -> str:
# 1. Schema — does it match expected structure?
parsed = schema.parse(raw_output)
# 2. Grounding — are claims supported by source documents?
assert_grounded(parsed, sources)
# 3. Safety — toxicity, PII leakage, prompt leakage
assert_safe(parsed, max_toxicity=0.5)
# 4. Size — prevent token-bomb responses
assert len(parsed.text) < MAX_OUTPUT_CHARS
return parsed.text
PII Masking
PII detection and masking for LLM observability pipelines and logging.
| Rule | Description |
|------|-------------|
| pii-detection.md | Microsoft Presidio, regex patterns, LLM Guard Anonymize |
| pii-redaction.md | Langfuse mask callback, structlog/loguru processors, Vault deanonymization |
Key Decisions: Presidio for enterprise | Replace with type tokens | Use mask callback at init
Scanning
Automated security scanning for dependencies, code, and secrets.
| Rule | Description |
|------|-------------|
| scanning-dependency.md | npm audit, pip-audit, Trivy container scanning, CI gating |
| scanning-sast.md | Semgrep and Bandit static analysis, custom rules, pre-commit |
| scanning-secrets.md | Gitleaks, TruffleHog, detect-secrets with baseline management |
Key Decisions: Pre-commit hooks for shift-left | Block on critical/high | Gitleaks + detect-secrets baseline
Advanced Guardrails
Production LLM safety with NeMo Guardrails, Guardrails AI validators, and DeepTeam red-teaming.
| Rule | Description |
|------|-------------|
| guardrails-nemo.md | NeMo Guardrails, Colang 2.0 flows, Guardrails AI validators, layered validation |
| guardrails-llm-validation.md | DeepTeam red-teaming (40+ vulnerabilities), OWASP LLM Top 10 compliance |
Key Decisions: NeMo for flows, Guardrails AI for validators | Toxicity 0.5 threshold | Red-team pre-release + quarterly
Managed Hook Hierarchy (CC 2.1.49)
Plugin settings follow a 3-tier precedence:
| Tier | Source | Overridable? |
|------|--------|-------------|
| 1. Managed (plugin settings.json) | Plugin author ships defaults | Yes, by user |
| 2. Project (.claude/settings.json) | Repository config | Yes, by user |
| 3. User (~/.claude/settings.json) | Personal preferences | Final authority |
Security hooks shipped by OrchestKit are managed defaults — users can disable them but are warned. Enterprise admins can lock settings via managed profiles.
Anti-Patterns (FORBIDDEN)
# Authentication
user.password = request.form['password'] # Plaintext password storage
response_type=token # Implicit OAuth grant (deprecated)
return "Email not found" # Information disclosure
# Input Validation
"SELECT * FROM users WHERE name = '" + name + "'" # SQL injection
if (file.type === 'image/png') {...} # Trusting Content-Type header
# LLM Safety
prompt = f"Analyze for user {user_id}" # ID in prompt
artifact.user_id = llm_output["user_id"] # Trusting LLM-generated IDs
# PII
logger.info(f"User email: {user.email}") # Raw PII in logs
langfuse.trace(input=raw_prompt) # Unmasked observability data
Detailed Documentation
Load on demand with Read("${CLAUDE_SKILL_DIR}/references/<file>"):
| File | Content |
|------|---------|
| oauth-2.1-passkeys.md | OAuth 2.1, PKCE, DPoP, Passkeys/WebAuthn |
| request-context-pattern.md | Immutable request context for identity flow |
| tenant-isolation.md | Tenant-scoped repository, vector/full-text search |
| audit-logging.md | Sanitized structured logging, compliance |
| zod-v4-api.md | Zod v4 types, coercion, transforms, refinements |
| vulnerability-demos.md | OWASP vulnerable vs secure code examples |
| context-separation.md | LLM context separation architecture |
| output-guardrails.md | Output validation pipeline implementation |
| pre-llm-filtering.md | Tenant-scoped retrieval, content extraction |
| post-llm-attribution.md | Deterministic attribution pattern |
| prompt-audit.md | Prompt audit patterns, safe prompt builder |
| presidio-integration.md | Microsoft Presidio setup, custom recognizers |
| langfuse-mask-callback.md | Langfuse SDK mask implementation |
| llm-guard-sanitization.md | LLM Guard Anonymize/Deanonymize with Vault |
| logging-redaction.md | structlog/loguru pre-logging redaction |
Related Skills
api-design-framework- API security patternsork:rag-retrieval- RAG pipeline patterns requiring tenant-scoped retrievalllm-evaluation- Output quality assessment including hallucination detection
Capability Details
authentication
Keywords: password, hashing, JWT, token, OAuth, PKCE, passkey, WebAuthn, RBAC, session Solves:
- Implement secure authentication with modern standards
- JWT token management with proper expiry
- OAuth 2.1 with PKCE flow
- Passkeys/WebAuthn registration and login
- Role-based access control
defense-in-depth
Keywords: defense in depth, security layers, multi-layer, request context, tenant isolation Solves:
- How to secure AI applications end-to-end
- Implement 8-layer security architecture
- Create immutable request context
- Ensure tenant isolation at query level
input-validation
Keywords: schema, validate, Zod, Pydantic, sanitize, HTML, XSS, file upload Solves:
- Validate input against schemas (Zod v4, Pydantic)
- Prevent injection attacks with allowlists
- Sanitize HTML and prevent XSS
- Validate file uploads by magic bytes
owasp-top-10
Keywords: OWASP, sql injection, broken access control, CSRF, XSS, SSRF Solves:
- Fix OWASP Top 10 vulnerabilities
- Prevent SQL and command injection
- Implement CSRF protection
- Fix broken authentication
llm-safety
Keywords: prompt injection, context separation, guardrails, hallucination, LLM output Solves:
- Prevent prompt injection attacks
- Implement context separation (IDs around LLM)
- Validate LLM output with guardrail pipeline
- Deterministic post-LLM attribution
pii-masking
Keywords: PII, masking, Presidio, Langfuse, redact, GDPR, privacy Solves:
- Detect and mask PII in LLM pipelines
- Integrate masking with Langfuse observability
- Implement pre-logging redaction
- GDPR-compliant data handling