Quick Start
Create your first agent in just a few lines:Core Concepts
Agent Configuration
Every agent has three key components:- name: Identifies your agent
- model: The LLM to use (supports any LiteLLM model)
- instructions: System prompt that defines agent behavior
Model Selection
Agentor supports any model available through LiteLLM. Use theprovider/model-name format:
Model Settings
Customize model behavior withModelSettings:
Running Agents
Synchronous Execution
For simple, blocking execution:Async Execution
For better performance and concurrent operations:Batch Processing
Process multiple prompts concurrently:Conversation Context
Maintain conversation history with message format:Agent from Markdown
Create agents from markdown files with frontmatter:Advanced Features
Fallback Models
Automatically retry with fallback models on rate limits or errors:Structured Outputs
Get typed responses with Pydantic models:Agent Skills
Skills are folders of instructions and scripts that agents load dynamically:Thinking Mode
Get the agent’s reasoning process:Best Practices
gpt-5-mini, gpt-4o-minianthropic/claude-3.5-sonnet, gpt-4ogemini/gemini-2.5-flashinstructions = """
You are a technical support agent for a SaaS product.
Guidelines:
- Always be polite and professional
- Ask clarifying questions before assuming
- Provide step-by-step solutions
- If unsure, escalate to human support
"""
try:
result = await agent.arun(user_input)
except Exception as e:
print(f"Agent error: {e}")
# Fallback logic
Next Steps
- Learn how to add custom tools to your agents
- Set up streaming responses for real-time output
- Deploy your agent with the Celesto CLI
- Enable observability for production monitoring