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Overview

You can customize the system prompt by extending the SystemPrompt class. Internally, this adds extra instructions to the default system prompt.
Custom system prompts allow you to modify the agent’s behavior at a fundamental level. Use this feature carefully as it can significantly impact the agent’s performance and reliability.

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Basic Customization

Create a custom system prompt by inheriting from the base class. 
from openoperator import SystemPrompt

class MySystemPrompt(SystemPrompt):
    def important_rules(self) -> str:
        # Get existing rules from parent class
        existing_rules = super().important_rules()

        # Add your custom rules
        new_rules = """
9. MOST IMPORTANT RULE:
- ALWAYS open first a new tab and go to wikipedia.com no matter the task!!!
"""

        # Make sure to use this pattern otherwise the exiting rules will be lost
        return f'{existing_rules}\n{new_rules}'

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Using Custom System Prompt

Apply your custom system prompt when creating an agent: 
from openoperator import Agent, LLM

# Initialize the model
llm = LLM(model='openai/gpt-4o')

# Create agent with custom system prompt
agent = Agent(
    llm=llm,
    system_prompt_class=MySystemPrompt
)