Pii Detection

1"""
2Pii Detection
3=============================
4
5Example demonstrating how to use PII detection guardrails with Kern Agent.
6"""
7
8import asyncio
9
10from kern.agent import Agent
11from kern.exceptions import InputCheckError
12from kern.guardrails import PIIDetectionGuardrail
13from kern.models.openai import OpenAIResponses
14
15
16# ---------------------------------------------------------------------------
17# Create Agent
18# ---------------------------------------------------------------------------
19async def main():
20    """Demonstrate PII detection guardrails functionality."""
21    print("PII Detection Guardrails Demo")
22    print("=" * 50)
23
24    # Create an agent with PII detection protection
25    agent = Agent(
26        name="Privacy-Protected Agent",
27        model=OpenAIResponses(id="gpt-5-mini"),
28        pre_hooks=[PIIDetectionGuardrail()],
29        description="An agent that helps with customer service while protecting privacy.",
30        instructions="You are a helpful customer service assistant. Always protect user privacy and handle sensitive information appropriately.",
31    )
32
33    # Test 1: Normal request without PII (should work)
34    print("\n[TEST 1] Normal request without PII")
35    print("-" * 30)
36    try:
37        agent.print_response(
38            input="Can you help me understand your return policy?",
39        )
40        print("[OK] Normal request processed successfully")
41    except InputCheckError as e:
42        print(f"[ERROR] Unexpected error: {e}")
43
44    # Test 2: Request with SSN (should be blocked)
45    print("\n[TEST 2] Input containing SSN")
46    print("-" * 30)
47    try:
48        agent.print_response(
49            input="Hi, my Social Security Number is 123-45-6789. Can you help me with my account?",
50        )
51        print("[WARNING] This should have been blocked!")
52    except InputCheckError as e:
53        print(f"[BLOCKED] PII blocked: {e.message}")
54        print(f"   Trigger: {e.check_trigger}")
55
56    # Test 3: Request with credit card (should be blocked)
57    print("\n[TEST 3] Input containing credit card")
58    print("-" * 30)
59    try:
60        agent.print_response(
61            input="I'd like to update my payment method. My new card number is 4532 1234 5678 9012.",
62        )
63        print("[WARNING] This should have been blocked!")
64    except InputCheckError as e:
65        print(f"[BLOCKED] PII blocked: {e.message}")
66        print(f"   Trigger: {e.check_trigger}")
67
68    # Test 4: Request with email address (should be blocked)
69    print("\n[TEST 4] Input containing email address")
70    print("-" * 30)
71    try:
72        agent.print_response(
73            input="Please send the receipt to john.doe@example.com for my recent purchase.",
74        )
75        print("[WARNING] This should have been blocked!")
76    except InputCheckError as e:
77        print(f"[BLOCKED] PII blocked: {e.message}")
78        print(f"   Trigger: {e.check_trigger}")
79
80    # Test 5: Request with phone number (should be blocked)
81    print("\n[TEST 5] Input containing phone number")
82    print("-" * 30)
83    try:
84        agent.print_response(
85            input="My phone number is 555-123-4567. Please call me about my order status.",
86        )
87        print("[WARNING] This should have been blocked!")
88    except InputCheckError as e:
89        print(f"[BLOCKED] PII blocked: {e.message}")
90        print(f"   Trigger: {e.check_trigger}")
91
92    # Test 6: Mixed PII in context (should be blocked)
93    print("\n[TEST 6] Multiple PII types in one request")
94    print("-" * 30)
95    try:
96        agent.print_response(
97            input="Hi, I'm John Smith. My email is john@company.com and phone is 555.987.6543. I need help with my account.",
98        )
99        print("[WARNING] This should have been blocked!")
100    except InputCheckError as e:
101        print(f"[BLOCKED] PII blocked: {e.message}")
102        print(f"   Trigger: {e.check_trigger}")
103
104    # Test 7: Edge case - formatted differently (should still be blocked)
105    print("\n[TEST 7] PII with different formatting")
106    print("-" * 30)
107    try:
108        agent.print_response(
109            input="Can you verify my credit card ending in 4532123456789012?",
110        )
111        print("[WARNING] This should have been blocked!")
112    except InputCheckError as e:
113        print(f"[BLOCKED] PII blocked: {e.message}")
114        print(f"   Trigger: {e.check_trigger}")
115
116    print("\n" + "=" * 50)
117    print("PII Detection Demo Complete")
118    print("All sensitive information was successfully blocked!")
119
120    # Create an agent with PII detection which masks the PII in the input
121    agent = Agent(
122        name="Privacy-Protected Agent (Masked)",
123        model=OpenAIResponses(id="gpt-5-mini"),
124        pre_hooks=[PIIDetectionGuardrail(mask_pii=True)],
125        description="An agent that helps with customer service while protecting privacy.",
126        instructions="You are a helpful customer service assistant. Always protect user privacy and handle sensitive information appropriately.",
127    )
128
129    # Test 8: Request with SSN (should be masked)
130    print("\n[TEST 8] Input containing SSN (masked mode)")
131    print("-" * 30)
132    agent.print_response(
133        input="Hi, my Social Security Number is 123-45-6789. Can you help me with my account?",
134    )
135
136
137# ---------------------------------------------------------------------------
138# Run Agent
139# ---------------------------------------------------------------------------
140if __name__ == "__main__":
141    asyncio.run(main())

1# Clone and setup repo
2git clone https://github.com/kern-ai/kern.git
3cd kern/cookbook/02_agents/08_guardrails
4
5# Create and activate virtual environment
6./scripts/demo_setup.sh
7source .venvs/demo/bin/activate
8
9python pii_detection.py