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Concept

Agents in CAMEL are autonomous entities capable of performing specific tasks through interaction with language models and other components. Each agent is designed with a particular role and capability, allowing them to work independently or collaboratively to achieve complex goals.
Think of an agent as an AI-powered teammate one that brings a defined role, memory, and tool-using abilities to every workflow. CAMEL’s agents are composable, robust, and can be extended with custom logic.

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Base Agent Architecture

All CAMEL agents inherit from the BaseAgent abstract class, which defines two essential methods:
MethodPurposeDescription
reset()State ManagementResets the agent to its initial state
step()Task ExecutionPerforms a single step of the agent’s operation

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Types

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ChatAgent

The ChatAgent is the primary implementation that handles conversations with language models. It supports:
  • System message configuration for role definition
  • Memory management for conversation history
  • Tool/function calling capabilities
  • Response formatting and structured outputs
  • Multiple model backend support with scheduling strategies
  • Async operation support

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Usage

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Basic ChatAgent Usage

from camel.agents import ChatAgent

# Create a chat agent with a system message
agent = ChatAgent(system_message="You are a helpful assistant.")

# Step through a conversation
response = agent.step("Hello, can you help me?")

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Simplified Agent Creation

The ChatAgent supports multiple ways to specify the model: 
from camel.agents import ChatAgent
from camel.models import ModelFactory
from camel.types import ModelPlatformType, ModelType

# Method 1: Using just a string for the model name (default model platform is used)
agent_1 = ChatAgent("You are a helpful assistant.", model="gpt-4o-mini")

# Method 2: Using a ModelType enum (default model platform is used)
agent_2 = ChatAgent("You are a helpful assistant.", model=ModelType.GPT_4O_MINI)

# Method 3: Using a tuple of strings (platform, model)
agent_3 = ChatAgent("You are a helpful assistant.", model=("openai", "gpt-4o-mini"))

# Method 4: Using a tuple of enums
agent_4 = ChatAgent(
    "You are a helpful assistant.",
    model=(ModelPlatformType.ANTHROPIC, ModelType.CLAUDE_3_5_SONNET),
)

# Method 5: Using default model platform and default model type when none is specified
agent_5 = ChatAgent("You are a helpful assistant.")

# Method 6: Using a pre-created model with ModelFactory (original approach)
model = ModelFactory.create(
    model_platform=ModelPlatformType.OPENAI,  # Using enum
    model_type=ModelType.GPT_4O_MINI,         # Using enum
)
agent_6 = ChatAgent("You are a helpful assistant.", model=model)

# Method 7: Using ModelFactory with string parameters
model = ModelFactory.create(
    model_platform="openai",     # Using string
    model_type="gpt-4o-mini",    # Using string
)
agent_7 = ChatAgent("You are a helpful assistant.", model=model)

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Using Tools with Chat Agent

from camel.agents import ChatAgent
from camel.toolkits import FunctionTool

# Define a tool
def calculator(a: int, b: int) -> int:
    return a + b

# Create agent with tool
agent = ChatAgent(tools=[calculator])

# The agent can now use the calculator tool in conversations
response = agent.step("What is 5 + 3?")

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Structured Output

CAMEL’s ChatAgent can produce structured output by leveraging Pydantic models. This feature is especially useful when you need the agent to return data in a specific format, such as JSON. By defining a Pydantic model, you can ensure that the agent’s output is predictable and easy to parse.
Here’s how you can get a structured response from a ChatAgent. First, define a BaseModel that specifies the desired output fields. You can add descriptions to each field to guide the model.
from pydantic import BaseModel, Field
from typing import List

class JokeResponse(BaseModel):
    joke: str = Field(description="A joke")
    funny_level: int = Field(description="Funny level, from 1 to 10")

# Create agent with structured output
agent = ChatAgent(model="gpt-4o-mini")
response = agent.step("Tell me a joke.", response_format=JokeResponse)

# The response content is a JSON string
print(response.msgs[0].content)
# '{"joke": "Why don't scientists trust atoms? Because they make up everything!", "funny_level": 8}'

# Access the parsed Pydantic object
parsed_response = response.msgs[0].parsed
print(parsed_response.joke)
# "Why don't scientists trust atoms? Because they make up everything!"
print(parsed_response.funny_level)
# 8

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Best Practices

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Advanced Features

You can dynamically select which model an agent uses for each step by adding your own scheduling strategy.
def custom_strategy(models):
    # Custom model selection logic
    return models[0]

agent.add_model_scheduling_strategy("custom", custom_strategy)