"""
Custom Guardrail
=============================
Custom Guardrail.
"""
from agno.agent import Agent
from agno.exceptions import CheckTrigger, InputCheckError
from agno.guardrails.base import BaseGuardrail
from agno.models.openai import OpenAIResponses
class TopicGuardrail(BaseGuardrail):
"""Blocks requests that ask for dangerous instructions."""
def check(self, run_input) -> None:
content = (run_input.input_content or "").lower()
blocked_terms = ["build malware", "phishing template", "exploit"]
if any(term in content for term in blocked_terms):
raise InputCheckError(
"Input contains blocked security-abuse content.",
check_trigger=CheckTrigger.INPUT_NOT_ALLOWED,
)
async def async_check(self, run_input) -> None:
self.check(run_input)
# ---------------------------------------------------------------------------
# Create Agent
# ---------------------------------------------------------------------------
agent = Agent(
name="Guarded Agent",
model=OpenAIResponses(id="gpt-5.2"),
pre_hooks=[TopicGuardrail()],
)
# ---------------------------------------------------------------------------
# Run Agent
# ---------------------------------------------------------------------------
if __name__ == "__main__":
agent.print_response(
"Explain secure password management best practices.", stream=True
)
Run the Example
# Clone and setup repo
git clone https://github.com/agno-agi/agno.git
cd agno/cookbook/02_agents/08_guardrails
# Create and activate virtual environment
./scripts/demo_setup.sh
source .venvs/demo/bin/activate
python custom_guardrail.py