Python AI Agent Frameworks Guide

Overview
Framework Comparison Matrix
Strands Agents
LangGraph
CrewAI
LangChain
AutoGen
AWS Bedrock Integration
Choosing the Right Framework
Implementation Examples

Overview

AI agent frameworks provide the orchestration layer for building intelligent systems that can reason, plan, and execute tasks autonomously. This guide covers the major Python frameworks and their integration with AWS services, particularly Amazon Bedrock.

What is an AI Agent?

An AI agent is an autonomous system that: - Perceives its environment through inputs - Reasons about goals and plans - Takes actions using tools and APIs - Learns from feedback and outcomes

Why Use a Framework?

Without Framework:
├── Manual prompt engineering
├── Custom tool integration
├── State management from scratch
├── Error handling and retries
└── Observability and logging

With Framework:
├── ✅ Pre-built agent patterns
├── ✅ Tool integration abstractions
├── ✅ State management built-in
├── ✅ Automatic error handling
└── ✅ Observability and tracing

Framework Comparison Matrix

Framework	Developer	Philosophy	Complexity	AWS Integration	Best For
Strands	AWS	Model-driven, minimal scaffolding	Low	Native (Bedrock-first)	AWS-native apps, quick prototypes
LangGraph	LangChain	Stateful graph workflows	Medium-High	Excellent	Complex workflows, state machines
CrewAI	CrewAI Inc	Role-based teams	Low-Medium	Good	Multi-agent collaboration
LangChain	LangChain	Composable chains	Medium	Excellent	RAG, chains, general purpose
AutoGen	Microsoft	Conversational agents	Medium	Good	Research, multi-agent conversations

Key Characteristics

Architecture Patterns:

┌─────────────────────────────────────────────────────────────┐
│                    FRAMEWORK PATTERNS                        │
├─────────────────────────────────────────────────────────────┤
│                                                              │
│  STRANDS: Model-Driven                                      │
│  ┌──────────┐                                               │
│  │   LLM    │ ← Drives everything                           │
│  └────┬─────┘                                               │
│       ├─→ Plans                                             │
│       ├─→ Executes Tools                                    │
│       └─→ Reasons                                           │
│                                                              │
│  LANGGRAPH: State Machine                                   │
│  ┌─────┐    ┌─────┐    ┌─────┐                            │
│  │Node1│───→│Node2│───→│Node3│                            │
│  └─────┘    └─────┘    └─────┘                            │
│     ↑          │          │                                 │
│     └──────────┴──────────┘                                │
│                                                              │
│  CREWAI: Role-Based Teams                                   │
│  ┌──────────┐  ┌──────────┐  ┌──────────┐                │
│  │Researcher│→ │ Analyst  │→ │  Writer  │                │
│  └──────────┘  └──────────┘  └──────────┘                │
│                                                              │
│  LANGCHAIN: Sequential Chains                               │
│  Input → Chain1 → Chain2 → Chain3 → Output                 │
│                                                              │
│  AUTOGEN: Conversational                                    │
│  ┌──────┐     ┌──────┐                                     │
│  │Agent1│ ←──→│Agent2│                                     │
│  └──────┘     └──────┘                                     │
│      ↕           ↕                                          │
│  ┌──────┐     ┌──────┐                                     │
│  │Agent3│ ←──→│Agent4│                                     │
│  └──────┘     └──────┘                                     │
│                                                              │
└─────────────────────────────────────────────────────────────┘

Strands Agents

Developer: AWS
License: Apache 2.0
GitHub: strands-agents/sdk-python

Philosophy

Strands takes a model-driven approach - trust the LLM to handle planning, reasoning, and tool execution with minimal scaffolding. The framework stays out of your way and lets the model do the heavy lifting.

Core Characteristics

Strengths: - ✅ Minimal code - agents in ~10 lines - ✅ AWS-native with Bedrock-first design - ✅ Model-agnostic (Bedrock, OpenAI, Anthropic, local models) - ✅ MCP (Model Context Protocol) tool integration - ✅ Streaming support built-in - ✅ Production-ready observability and tracing - ✅ Lightweight with minimal dependencies

Limitations: - ❌ Newer framework (less community resources) - ❌ Less control over agent workflow - ❌ Simpler patterns (not for complex state machines)

Architecture

# Strands Agent Architecture
from strands_agents import Agent, Tool

# 1. Define tools
tools = [
    Tool(name="search", function=search_function),
    Tool(name="calculator", function=calc_function)
]

# 2. Create agent (model drives everything)
agent = Agent(
    model="bedrock/anthropic.claude-3-sonnet",
    system_prompt="You are a helpful assistant",
    tools=tools
)

# 3. Run - model decides what to do
response = agent.run("What's 25 * 4 and search for Python tutorials")
# Model automatically:
# - Plans the approach
# - Calls calculator tool
# - Calls search tool
# - Synthesizes response

AWS Bedrock Integration

Native Bedrock Support:

from strands_agents import Agent
import boto3

# Direct Bedrock integration
agent = Agent(
    model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0",
    region="us-east-1",
    tools=[...]
)

# Or with custom boto3 client
bedrock_client = boto3.client('bedrock-runtime', region_name='us-west-2')
agent = Agent(
    model="bedrock/anthropic.claude-3-haiku",
    client=bedrock_client,
    tools=[...]
)

Use Cases

Best for: - AWS-native applications - Quick prototypes and MVPs - Simple to medium complexity agents - When you want minimal code - Bedrock-first deployments

Not ideal for: - Complex multi-step workflows with branching - Fine-grained control over execution flow - When you need explicit state machines

Example: Customer Support Agent

from strands_agents import Agent, Tool

def query_knowledge_base(query: str) -> str:
    """Query Bedrock Knowledge Base"""
    # Integration with Bedrock KB
    return kb_response

def create_ticket(issue: str, priority: str) -> str:
    """Create support ticket"""
    return ticket_id

agent = Agent(
    model="bedrock/anthropic.claude-3-sonnet",
    system_prompt="""You are a customer support agent.
    Help users with their questions using the knowledge base.
    Create tickets for issues you cannot resolve.""",
    tools=[
        Tool(name="search_kb", function=query_knowledge_base),
        Tool(name="create_ticket", function=create_ticket)
    ]
)

# Agent automatically decides when to search KB vs create ticket
response = agent.run("My order hasn't arrived in 2 weeks")

LangGraph

Developer: LangChain
License: MIT
GitHub: langchain-ai/langgraph

Philosophy

LangGraph treats agent workflows as stateful graphs where nodes represent actions and edges represent transitions. This gives you explicit control over execution flow, state management, and conditional branching.

Core Characteristics

Strengths: - ✅ Explicit control over workflow logic - ✅ Built-in state management and persistence - ✅ Conditional branching and loops - ✅ Human-in-the-loop support - ✅ Time-travel debugging - ✅ Excellent for complex workflows - ✅ Strong AWS Bedrock integration

Limitations: - ❌ Steeper learning curve - ❌ More verbose code - ❌ Requires understanding of graph concepts - ❌ Overkill for simple agents

Architecture

# LangGraph Architecture - Stateful Graph
from langgraph.graph import StateGraph, END
from langchain_aws import ChatBedrock

# 1. Define state
class AgentState(TypedDict):
    messages: list
    next_action: str
    data: dict

# 2. Define nodes (actions)
def research_node(state: AgentState):
    # Perform research
    return {"data": research_results}

def analyze_node(state: AgentState):
    # Analyze data
    return {"data": analysis}

def decide_next(state: AgentState):
    # Conditional routing
    if state["data"]["confidence"] > 0.8:
        return "finalize"
    return "research"

# 3. Build graph
workflow = StateGraph(AgentState)
workflow.add_node("research", research_node)
workflow.add_node("analyze", analyze_node)
workflow.add_node("finalize", finalize_node)

# 4. Add edges (transitions)
workflow.add_edge("research", "analyze")
workflow.add_conditional_edges(
    "analyze",
    decide_next,
    {"research": "research", "finalize": "finalize"}
)
workflow.add_edge("finalize", END)

# 5. Compile and run
app = workflow.compile()
result = app.invoke({"messages": [user_input]})

AWS Bedrock Integration

Bedrock Models in LangGraph:

from langgraph.graph import StateGraph
from langchain_aws import ChatBedrock
from langchain_core.messages import HumanMessage

# Initialize Bedrock model
llm = ChatBedrock(
    model_id="anthropic.claude-3-sonnet-20240229-v1:0",
    region_name="us-east-1",
    model_kwargs={"temperature": 0.7}
)

# Use in graph nodes
def agent_node(state):
    messages = state["messages"]
    response = llm.invoke(messages)
    return {"messages": messages + [response]}

# Multi-agent with different Bedrock models
researcher_llm = ChatBedrock(model_id="anthropic.claude-3-sonnet")
analyst_llm = ChatBedrock(model_id="anthropic.claude-3-haiku")  # Faster/cheaper

workflow = StateGraph(AgentState)
workflow.add_node("research", lambda s: research_with_llm(s, researcher_llm))
workflow.add_node("analyze", lambda s: analyze_with_llm(s, analyst_llm))

Integration with Bedrock Knowledge Bases:

from langchain_aws import AmazonKnowledgeBasesRetriever

# Bedrock KB as retriever in LangGraph
kb_retriever = AmazonKnowledgeBasesRetriever(
    knowledge_base_id="KB123456",
    retrieval_config={"vectorSearchConfiguration": {"numberOfResults": 5}}
)

def rag_node(state):
    query = state["query"]
    # Retrieve from Bedrock KB
    docs = kb_retriever.get_relevant_documents(query)
    # Generate with Bedrock model
    response = llm.invoke(f"Context: {docs}\n\nQuestion: {query}")
    return {"answer": response}

Use Cases

Best for: - Complex multi-step workflows - Workflows with conditional logic - State persistence requirements - Human-in-the-loop applications - When you need explicit control - Multi-agent orchestration with routing

Example: Research & Analysis Pipeline

from langgraph.graph import StateGraph, END
from langchain_aws import ChatBedrock

class ResearchState(TypedDict):
    topic: str
    research_data: list
    analysis: str
    retry_count: int

llm = ChatBedrock(model_id="anthropic.claude-3-sonnet")

def research(state):
    # Research the topic
    data = perform_research(state["topic"])
    return {"research_data": data}

def analyze(state):
    # Analyze research data
    analysis = llm.invoke(f"Analyze: {state['research_data']}")
    return {"analysis": analysis.content}

def quality_check(state):
    # Decide if analysis is good enough
    if len(state["analysis"]) > 500:
        return "finalize"
    elif state["retry_count"] < 3:
        return "research"  # Retry
    return "finalize"

workflow = StateGraph(ResearchState)
workflow.add_node("research", research)
workflow.add_node("analyze", analyze)
workflow.add_node("finalize", lambda s: s)

workflow.set_entry_point("research")
workflow.add_edge("research", "analyze")
workflow.add_conditional_edges("analyze", quality_check)
workflow.add_edge("finalize", END)

app = workflow.compile()
result = app.invoke({"topic": "AI trends 2025", "retry_count": 0})

CrewAI

Developer: CrewAI Inc
License: MIT
GitHub: joaomdmoura/crewAI

Philosophy

CrewAI uses a role-based team metaphor where you define agents by their role, goal, and backstory, then assemble them into "crews" that collaborate toward shared objectives. Think of it as building a team of specialists.

Core Characteristics

Strengths: - ✅ Intuitive role-based design - ✅ Easy to understand and use - ✅ Great for multi-agent collaboration - ✅ Built-in task delegation - ✅ Sequential and hierarchical processes - ✅ Good documentation and examples - ✅ AWS Bedrock integration via tools

Limitations: - ❌ Less flexible than graph-based approaches - ❌ Opinionated structure - ❌ Limited control over execution flow - ❌ Can be verbose for simple tasks

Architecture

# CrewAI Architecture - Role-Based Teams
from crewai import Agent, Task, Crew
from langchain_aws import ChatBedrock

# 1. Define LLM
llm = ChatBedrock(model_id="anthropic.claude-3-sonnet")

# 2. Create agents with roles
researcher = Agent(
    role="Research Specialist",
    goal="Find accurate information on given topics",
    backstory="Expert researcher with 10 years experience",
    llm=llm,
    tools=[search_tool, web_scraper]
)

analyst = Agent(
    role="Data Analyst",
    goal="Analyze research data and extract insights",
    backstory="Senior analyst specializing in trend analysis",
    llm=llm,
    tools=[analysis_tool]
)

writer = Agent(
    role="Content Writer",
    goal="Create engaging content from analysis",
    backstory="Professional writer with technical expertise",
    llm=llm,
    tools=[grammar_check]
)

# 3. Define tasks
research_task = Task(
    description="Research AI trends in 2025",
    agent=researcher,
    expected_output="Comprehensive research report"
)

analysis_task = Task(
    description="Analyze research findings",
    agent=analyst,
    expected_output="Key insights and trends"
)

writing_task = Task(
    description="Write article based on analysis",
    agent=writer,
    expected_output="Publication-ready article"
)

# 4. Create crew
crew = Crew(
    agents=[researcher, analyst, writer],
    tasks=[research_task, analysis_task, writing_task],
    process="sequential"  # or "hierarchical"
)

# 5. Execute
result = crew.kickoff()

AWS Bedrock Integration

Using Bedrock Models:

from crewai import Agent, Task, Crew
from langchain_aws import ChatBedrock

# Different Bedrock models for different agents
researcher_llm = ChatBedrock(
    model_id="anthropic.claude-3-sonnet-20240229-v1:0",
    region_name="us-east-1"
)

writer_llm = ChatBedrock(
    model_id="anthropic.claude-3-haiku-20240307-v1:0",  # Faster for writing
    region_name="us-east-1"
)

researcher = Agent(
    role="Researcher",
    goal="Deep research",
    llm=researcher_llm,
    tools=[...]
)

writer = Agent(
    role="Writer",
    goal="Create content",
    llm=writer_llm,
    tools=[...]
)

Integration with Bedrock Agents:

from crewai_tools import BedrockInvokeAgentTool

# Use Bedrock Agent as a tool in CrewAI
bedrock_agent_tool = BedrockInvokeAgentTool(
    agent_id="AGENT123",
    agent_alias_id="ALIAS456",
    region_name="us-east-1"
)

# CrewAI agent can invoke Bedrock Agent
crewai_agent = Agent(
    role="Coordinator",
    goal="Coordinate with Bedrock agents",
    tools=[bedrock_agent_tool],
    llm=ChatBedrock(model_id="anthropic.claude-3-sonnet")
)

Bedrock Knowledge Bases Integration:

from langchain_aws import AmazonKnowledgeBasesRetriever
from crewai_tools import LangChainTool

# Wrap Bedrock KB as CrewAI tool
kb_retriever = AmazonKnowledgeBasesRetriever(
    knowledge_base_id="KB123456"
)

kb_tool = LangChainTool(
    name="Company Knowledge Base",
    description="Search company documentation and policies",
    func=lambda q: kb_retriever.get_relevant_documents(q)
)

support_agent = Agent(
    role="Support Specialist",
    goal="Help customers using company knowledge",
    tools=[kb_tool],
    llm=ChatBedrock(model_id="anthropic.claude-3-sonnet")
)

Use Cases

Best for: - Multi-agent collaboration scenarios - Role-based task delegation - Content creation pipelines - Research and analysis workflows - When team metaphor fits naturally - Regulatory compliance automation

Example: Compliance Review System

from crewai import Agent, Task, Crew
from langchain_aws import ChatBedrock, AmazonKnowledgeBasesRetriever

llm = ChatBedrock(model_id="anthropic.claude-3-sonnet")

# Agent 1: Document Reviewer
reviewer = Agent(
    role="Compliance Reviewer",
    goal="Review documents for regulatory compliance",
    backstory="Expert in financial regulations with 15 years experience",
    llm=llm,
    tools=[kb_search_tool]
)

# Agent 2: Risk Assessor
assessor = Agent(
    role="Risk Assessor",
    goal="Assess compliance risks and severity",
    backstory="Risk management specialist",
    llm=llm,
    tools=[risk_calculator]
)

# Agent 3: Report Generator
reporter = Agent(
    role="Report Generator",
    goal="Generate compliance reports",
    backstory="Technical writer specializing in compliance",
    llm=llm,
    tools=[template_tool]
)

# Tasks
review_task = Task(
    description="Review contract for compliance issues",
    agent=reviewer
)

assess_task = Task(
    description="Assess risk level of identified issues",
    agent=assessor
)

report_task = Task(
    description="Generate compliance report",
    agent=reporter
)

# Crew
compliance_crew = Crew(
    agents=[reviewer, assessor, reporter],
    tasks=[review_task, assess_task, report_task],
    process="sequential"
)

result = compliance_crew.kickoff(inputs={"contract": contract_text})

LangChain

Developer: LangChain
License: MIT
GitHub: langchain-ai/langchain

Philosophy

LangChain provides composable building blocks (chains, agents, tools, memory) that you can combine to build LLM applications. It's the most mature and comprehensive framework with extensive integrations.

Core Characteristics

Strengths: - ✅ Mature ecosystem with extensive integrations - ✅ Comprehensive documentation - ✅ Large community and resources - ✅ Excellent AWS Bedrock support - ✅ RAG capabilities built-in - ✅ Flexible and composable - ✅ Production-ready features

Limitations: - ❌ Can be overwhelming for beginners - ❌ Frequent API changes - ❌ Sometimes over-engineered for simple tasks - ❌ Large dependency footprint

Architecture

# LangChain Architecture - Composable Chains
from langchain_aws import ChatBedrock
from langchain.agents import AgentExecutor, create_tool_calling_agent
from langchain_core.prompts import ChatPromptTemplate
from langchain_core.tools import tool

# 1. Initialize LLM
llm = ChatBedrock(
    model_id="anthropic.claude-3-sonnet-20240229-v1:0",
    region_name="us-east-1"
)

# 2. Define tools
@tool
def search_database(query: str) -> str:
    """Search the company database"""
    return db_results

@tool
def send_email(to: str, subject: str, body: str) -> str:
    """Send an email"""
    return "Email sent"

tools = [search_database, send_email]

# 3. Create prompt
prompt = ChatPromptTemplate.from_messages([
    ("system", "You are a helpful assistant"),
    ("human", "{input}"),
    ("placeholder", "{agent_scratchpad}")
])

# 4. Create agent
agent = create_tool_calling_agent(llm, tools, prompt)

# 5. Create executor
agent_executor = AgentExecutor(
    agent=agent,
    tools=tools,
    verbose=True
)

# 6. Run
result = agent_executor.invoke({"input": "Search for customer X and email them"})

AWS Bedrock Integration

Comprehensive Bedrock Support:

from langchain_aws import ChatBedrock, BedrockEmbeddings
from langchain_aws import AmazonKnowledgeBasesRetriever
from langchain.agents import AgentExecutor

# 1. Chat Models
chat = ChatBedrock(
    model_id="anthropic.claude-3-sonnet-20240229-v1:0",
    model_kwargs={"temperature": 0.7, "max_tokens": 4096}
)

# 2. Embeddings
embeddings = BedrockEmbeddings(
    model_id="amazon.titan-embed-text-v2:0"
)

# 3. Knowledge Bases
kb_retriever = AmazonKnowledgeBasesRetriever(
    knowledge_base_id="KB123456",
    retrieval_config={
        "vectorSearchConfiguration": {
            "numberOfResults": 5,
            "overrideSearchType": "HYBRID"
        }
    }
)

# 4. Bedrock Agents
from langchain_aws.agents import BedrockAgentsRunnable

bedrock_agent = BedrockAgentsRunnable(
    agent_id="AGENT123",
    agent_alias_id="ALIAS456"
)

response = bedrock_agent.invoke({
    "input": "What's the weather?",
    "session_id": "session123"
})

RAG with Bedrock:

from langchain_aws import ChatBedrock, BedrockEmbeddings
from langchain_community.vectorstores import FAISS
from langchain.chains import RetrievalQA
from langchain.text_splitter import RecursiveCharacterTextSplitter

# 1. Load and split documents
text_splitter = RecursiveCharacterTextSplitter(
    chunk_size=1000,
    chunk_overlap=200
)
docs = text_splitter.split_documents(documents)

# 2. Create embeddings with Bedrock
embeddings = BedrockEmbeddings(
    model_id="amazon.titan-embed-text-v2:0"
)

# 3. Create vector store
vectorstore = FAISS.from_documents(docs, embeddings)

# 4. Create retrieval chain
llm = ChatBedrock(model_id="anthropic.claude-3-sonnet")

qa_chain = RetrievalQA.from_chain_type(
    llm=llm,
    chain_type="stuff",
    retriever=vectorstore.as_retriever(search_kwargs={"k": 5})
)

# 5. Query
answer = qa_chain.invoke({"query": "What is the return policy?"})

Use Cases

Best for: - RAG applications - General-purpose LLM apps - When you need extensive integrations - Production applications - Document processing pipelines - Chatbots and conversational AI

Example: Customer Support RAG System

from langchain_aws import ChatBedrock, AmazonKnowledgeBasesRetriever
from langchain.chains import ConversationalRetrievalChain
from langchain.memory import ConversationBufferMemory

# Bedrock components
llm = ChatBedrock(model_id="anthropic.claude-3-sonnet")
retriever = AmazonKnowledgeBasesRetriever(
    knowledge_base_id="KB123456"
)

# Memory for conversation history
memory = ConversationBufferMemory(
    memory_key="chat_history",
    return_messages=True,
    output_key="answer"
)

# Conversational RAG chain
qa_chain = ConversationalRetrievalChain.from_llm(
    llm=llm,
    retriever=retriever,
    memory=memory,
    return_source_documents=True
)

# Multi-turn conversation
response1 = qa_chain({"question": "What's your return policy?"})
response2 = qa_chain({"question": "How long does it take?"})  # Remembers context

AutoGen

Developer: Microsoft
License: MIT
GitHub: microsoft/autogen

Philosophy

AutoGen enables multi-agent conversations where agents communicate with each other to solve problems collaboratively. It emphasizes agent-to-agent interaction and supports both autonomous and human-in-the-loop workflows.

Core Characteristics

Strengths: - ✅ Powerful multi-agent conversations - ✅ Human-in-the-loop support - ✅ Code execution capabilities - ✅ Flexible conversation patterns - ✅ Good for research and experimentation - ✅ Microsoft ecosystem integration

Limitations: - ❌ Complex setup for production - ❌ Less AWS-native than other frameworks - ❌ Steeper learning curve - ❌ Can be unpredictable with many agents

Architecture

# AutoGen Architecture - Conversational Agents
import autogen

# 1. Configure LLM
config_list = [{
    "model": "anthropic.claude-3-sonnet",
    "api_type": "bedrock",
    "region": "us-east-1"
}]

# 2. Create agents
user_proxy = autogen.UserProxyAgent(
    name="User",
    human_input_mode="NEVER",
    code_execution_config={"work_dir": "coding"}
)

assistant = autogen.AssistantAgent(
    name="Assistant",
    llm_config={"config_list": config_list}
)

critic = autogen.AssistantAgent(
    name="Critic",
    system_message="Review and critique solutions",
    llm_config={"config_list": config_list}
)

# 3. Initiate conversation
user_proxy.initiate_chat(
    assistant,
    message="Write a Python function to calculate fibonacci"
)

# Agents converse until task is complete

AWS Bedrock Integration

Using Bedrock with AutoGen:

import autogen
import boto3
from typing import Dict, List

# Custom Bedrock client for AutoGen
class BedrockClient:
    def __init__(self, model_id: str, region: str):
        self.client = boto3.client('bedrock-runtime', region_name=region)
        self.model_id = model_id

    def create(self, messages: List[Dict], **kwargs):
        # Convert to Bedrock format and invoke
        response = self.client.invoke_model(
            modelId=self.model_id,
            body=json.dumps({
                "messages": messages,
                "max_tokens": kwargs.get("max_tokens", 4096),
                "temperature": kwargs.get("temperature", 0.7)
            })
        )
        return response

# Configure AutoGen with Bedrock
config_list = [{
    "model": "anthropic.claude-3-sonnet-20240229-v1:0",
    "api_type": "bedrock",
    "region_name": "us-east-1",
    "bedrock_client": BedrockClient(
        model_id="anthropic.claude-3-sonnet-20240229-v1:0",
        region="us-east-1"
    )
}]

# Create agents with Bedrock
assistant = autogen.AssistantAgent(
    name="Assistant",
    llm_config={"config_list": config_list}
)

Use Cases

Best for: - Research and experimentation - Code generation and execution - Multi-agent debates and discussions - Complex problem-solving requiring collaboration - When agent-to-agent communication is key

Example: Code Review System

import autogen

config_list = [{"model": "bedrock/anthropic.claude-3-sonnet"}]

# Developer agent
developer = autogen.AssistantAgent(
    name="Developer",
    system_message="You write Python code",
    llm_config={"config_list": config_list}
)

# Reviewer agent
reviewer = autogen.AssistantAgent(
    name="Reviewer",
    system_message="You review code for bugs and improvements",
    llm_config={"config_list": config_list}
)

# Tester agent
tester = autogen.UserProxyAgent(
    name="Tester",
    human_input_mode="NEVER",
    code_execution_config={"work_dir": "tests"}
)

# Group chat
groupchat = autogen.GroupChat(
    agents=[developer, reviewer, tester],
    messages=[],
    max_round=10
)

manager = autogen.GroupChatManager(
    groupchat=groupchat,
    llm_config={"config_list": config_list}
)

# Start collaborative code review
tester.initiate_chat(
    manager,
    message="Create a function to validate email addresses"
)

AWS Bedrock Integration

Bedrock-Specific Considerations

Model Selection by Framework:

Framework	Bedrock Integration	Ease of Use	Recommended Models
Strands	Native, first-class	⭐⭐⭐⭐⭐	All Bedrock models
LangGraph	Excellent via LangChain	⭐⭐⭐⭐	Claude 3, Titan
CrewAI	Good via LangChain	⭐⭐⭐⭐	Claude 3 Sonnet
LangChain	Excellent, comprehensive	⭐⭐⭐⭐⭐	All Bedrock models
AutoGen	Custom integration needed	⭐⭐⭐	Claude 3

Common Bedrock Patterns

1. Using Multiple Bedrock Models:

# Different models for different tasks
from langchain_aws import ChatBedrock

# Expensive, powerful model for complex reasoning
sonnet = ChatBedrock(
    model_id="anthropic.claude-3-sonnet-20240229-v1:0",
    model_kwargs={"temperature": 0.7}
)

# Cheaper, faster model for simple tasks
haiku = ChatBedrock(
    model_id="anthropic.claude-3-haiku-20240307-v1:0",
    model_kwargs={"temperature": 0.5}
)

# Use appropriately
complex_analysis = sonnet.invoke("Analyze this complex data...")
simple_summary = haiku.invoke("Summarize this text...")

2. Bedrock Knowledge Bases Integration:

# Works with all frameworks via LangChain
from langchain_aws import AmazonKnowledgeBasesRetriever

kb_retriever = AmazonKnowledgeBasesRetriever(
    knowledge_base_id="YOUR_KB_ID",
    retrieval_config={
        "vectorSearchConfiguration": {
            "numberOfResults": 5,
            "overrideSearchType": "HYBRID"  # Vector + keyword
        }
    }
)

# Use in any framework
docs = kb_retriever.get_relevant_documents("query")

3. Bedrock Guardrails:

from langchain_aws import ChatBedrock

# Apply guardrails to any Bedrock model
llm = ChatBedrock(
    model_id="anthropic.claude-3-sonnet-20240229-v1:0",
    guardrails={
        "guardrailIdentifier": "your-guardrail-id",
        "guardrailVersion": "1",
        "trace": "enabled"
    }
)

# Guardrails automatically filter harmful content
response = llm.invoke("User input...")

4. Cost Optimization with Bedrock:

# Strategy: Use cheaper models where possible
from langchain_aws import ChatBedrock

class CostOptimizedAgent:
    def __init__(self):
        # Haiku for simple tasks (cheapest)
        self.haiku = ChatBedrock(
            model_id="anthropic.claude-3-haiku-20240307-v1:0"
        )
        # Sonnet for complex tasks (balanced)
        self.sonnet = ChatBedrock(
            model_id="anthropic.claude-3-sonnet-20240229-v1:0"
        )
        # Opus for critical tasks (most expensive)
        self.opus = ChatBedrock(
            model_id="anthropic.claude-3-opus-20240229-v1:0"
        )

    def route_query(self, query: str, complexity: str):
        if complexity == "simple":
            return self.haiku.invoke(query)
        elif complexity == "medium":
            return self.sonnet.invoke(query)
        else:
            return self.opus.invoke(query)

Non-Bedrock AWS Services Integration

1. Lambda Deployment:

# Deploy any framework as Lambda function
import json
from strands_agents import Agent

# Initialize agent (cold start)
agent = Agent(
    model="bedrock/anthropic.claude-3-sonnet",
    tools=[...]
)

def lambda_handler(event, context):
    user_input = event['body']
    response = agent.run(user_input)

    return {
        'statusCode': 200,
        'body': json.dumps({'response': response})
    }

2. S3 for Document Storage:

import boto3
from langchain_community.document_loaders import S3FileLoader

# Load documents from S3
s3_client = boto3.client('s3')
loader = S3FileLoader(
    bucket="my-docs-bucket",
    key="documents/policy.pdf"
)
documents = loader.load()

# Process with any framework

3. DynamoDB for State Persistence:

import boto3
from boto3.dynamodb.conditions import Key

dynamodb = boto3.resource('dynamodb')
table = dynamodb.Table('agent-state')

# Save agent state
def save_state(session_id: str, state: dict):
    table.put_item(
        Item={
            'session_id': session_id,
            'state': state,
            'timestamp': int(time.time())
        }
    )

# Load agent state
def load_state(session_id: str):
    response = table.get_item(Key={'session_id': session_id})
    return response.get('Item', {}).get('state', {})

4. EventBridge for Agent Orchestration:

import boto3

eventbridge = boto3.client('events')

# Trigger agent workflows via events
def trigger_agent_workflow(workflow_type: str, data: dict):
    eventbridge.put_events(
        Entries=[{
            'Source': 'agent.system',
            'DetailType': workflow_type,
            'Detail': json.dumps(data)
        }]
    )

Choosing the Right Framework

Decision Matrix

┌─────────────────────────────────────────────────────────────┐
│                  FRAMEWORK SELECTION GUIDE                   │
├─────────────────────────────────────────────────────────────┤
│                                                              │
│  START HERE                                                  │
│      │                                                       │
│      ▼                                                       │
│  Are you building on AWS?                                   │
│      │                                                       │
│      ├─ YES ──→ Need complex workflows?                     │
│      │            │                                          │
│      │            ├─ YES ──→ LangGraph                      │
│      │            │                                          │
│      │            └─ NO ──→ Strands (simplest)              │
│      │                                                       │
│      └─ NO ──→ Need multi-agent teams?                      │
│                  │                                           │
│                  ├─ YES ──→ CrewAI or AutoGen               │
│                  │                                           │
│                  └─ NO ──→ LangChain (most flexible)        │
│                                                              │
└─────────────────────────────────────────────────────────────┘

Use Case Recommendations

Simple Chatbot / Assistant: - ✅ Strands - Minimal code, fast setup - ✅ LangChain - If you need RAG - ❌ LangGraph - Overkill - ❌ CrewAI - Overkill - ❌ AutoGen - Overkill

RAG Application: - ✅ LangChain - Best RAG support - ✅ LangGraph - If complex retrieval logic - ✅ Strands - Simple RAG - ⚠️ CrewAI - Possible but not ideal - ❌ AutoGen - Not designed for RAG

Multi-Agent Collaboration: - ✅ CrewAI - Easiest for role-based teams - ✅ LangGraph - Most control - ✅ AutoGen - Best for agent conversations - ⚠️ LangChain - Possible but verbose - ❌ Strands - Not designed for this

Complex Workflow with Branching: - ✅ LangGraph - Purpose-built for this - ⚠️ LangChain - Possible but complex - ❌ Strands - Too simple - ❌ CrewAI - Limited branching - ❌ AutoGen - Not ideal

AWS-Native Application: - ✅ Strands - AWS-first design - ✅ LangChain - Excellent Bedrock support - ✅ LangGraph - Great Bedrock support - ⚠️ CrewAI - Good via LangChain - ⚠️ AutoGen - Requires custom integration

Research / Experimentation: - ✅ AutoGen - Great for exploration - ✅ LangGraph - Good debugging tools - ✅ Strands - Quick prototyping - ⚠️ LangChain - Can be heavy - ⚠️ CrewAI - More opinionated

Complexity vs Control Trade-off

High Control
    │
    │  LangGraph ●
    │              
    │                    AutoGen ●
    │
    │  LangChain ●
    │
    │              CrewAI ●
    │
    │                        Strands ●
    │
Low Control
    └────────────────────────────────────→
       Low Complexity        High Complexity

Team Skill Level Considerations

Beginner Team: 1. Strands - Simplest, minimal concepts 2. CrewAI - Intuitive role-based model 3. LangChain - Good docs but more to learn

Intermediate Team: 1. LangChain - Flexible, well-documented 2. CrewAI - Easy multi-agent 3. LangGraph - If workflows are complex

Advanced Team: 1. LangGraph - Maximum control 2. AutoGen - Complex multi-agent 3. Custom - Build your own

Implementation Examples

Example 1: Customer Support Agent (Strands)

Scenario: Simple customer support bot with knowledge base access

from strands_agents import Agent, Tool
import boto3

# Bedrock KB tool
def search_knowledge_base(query: str) -> str:
    """Search company knowledge base"""
    client = boto3.client('bedrock-agent-runtime')
    response = client.retrieve(
        knowledgeBaseId='KB123456',
        retrievalQuery={'text': query}
    )
    return response['retrievalResults']

# Create agent
agent = Agent(
    model="bedrock/anthropic.claude-3-sonnet-20240229-v1:0",
    system_prompt="""You are a helpful customer support agent.
    Use the knowledge base to answer questions accurately.
    If you cannot find an answer, politely say so.""",
    tools=[
        Tool(name="search_kb", function=search_knowledge_base)
    ]
)

# Use
response = agent.run("What's your return policy for electronics?")
print(response)

Why Strands? - Simple use case - Minimal code required - AWS-native - No complex workflows needed

Example 2: Document Analysis Pipeline (LangGraph)

Scenario: Multi-step document analysis with quality checks and retries

from langgraph.graph import StateGraph, END
from langchain_aws import ChatBedrock
from typing import TypedDict

class AnalysisState(TypedDict):
    document: str
    summary: str
    key_points: list
    quality_score: float
    retry_count: int

llm = ChatBedrock(model_id="anthropic.claude-3-sonnet-20240229-v1:0")

# Nodes
def summarize(state: AnalysisState):
    summary = llm.invoke(f"Summarize: {state['document']}")
    return {"summary": summary.content}

def extract_points(state: AnalysisState):
    points = llm.invoke(f"Extract key points from: {state['summary']}")
    return {"key_points": points.content.split('\n')}

def quality_check(state: AnalysisState):
    # Check quality
    score = len(state['key_points']) / 10.0
    return {"quality_score": score}

def route_decision(state: AnalysisState):
    if state['quality_score'] >= 0.7:
        return "finalize"
    elif state['retry_count'] < 3:
        return "retry"
    return "finalize"

def retry_node(state: AnalysisState):
    return {"retry_count": state['retry_count'] + 1}

# Build graph
workflow = StateGraph(AnalysisState)
workflow.add_node("summarize", summarize)
workflow.add_node("extract", extract_points)
workflow.add_node("check", quality_check)
workflow.add_node("retry", retry_node)
workflow.add_node("finalize", lambda s: s)

workflow.set_entry_point("summarize")
workflow.add_edge("summarize", "extract")
workflow.add_edge("extract", "check")
workflow.add_conditional_edges(
    "check",
    route_decision,
    {"retry": "summarize", "finalize": "finalize"}
)
workflow.add_edge("finalize", END)

app = workflow.compile()

# Run
result = app.invoke({
    "document": long_document,
    "retry_count": 0
})

Why LangGraph? - Complex workflow with conditional logic - Retry mechanism needed - State persistence across steps - Quality checks and routing

Example 3: Content Creation Team (CrewAI)

Scenario: Multi-agent team for blog post creation

from crewai import Agent, Task, Crew
from langchain_aws import ChatBedrock

llm = ChatBedrock(model_id="anthropic.claude-3-sonnet-20240229-v1:0")

# Define agents
researcher = Agent(
    role="Research Specialist",
    goal="Research topics thoroughly and gather accurate information",
    backstory="Expert researcher with 10 years of experience in tech",
    llm=llm,
    tools=[web_search_tool, kb_search_tool],
    verbose=True
)

writer = Agent(
    role="Content Writer",
    goal="Write engaging, SEO-optimized blog posts",
    backstory="Professional tech writer with strong SEO skills",
    llm=llm,
    tools=[grammar_tool],
    verbose=True
)

editor = Agent(
    role="Editor",
    goal="Review and improve content quality",
    backstory="Senior editor with eye for detail",
    llm=llm,
    verbose=True
)

# Define tasks
research_task = Task(
    description="Research the topic: {topic}. Find latest trends and statistics.",
    agent=researcher,
    expected_output="Comprehensive research report with sources"
)

writing_task = Task(
    description="Write a 1000-word blog post based on the research",
    agent=writer,
    expected_output="Complete blog post with SEO optimization"
)

editing_task = Task(
    description="Review and edit the blog post for quality and clarity",
    agent=editor,
    expected_output="Polished, publication-ready blog post"
)

# Create crew
content_crew = Crew(
    agents=[researcher, writer, editor],
    tasks=[research_task, writing_task, editing_task],
    process="sequential",
    verbose=True
)

# Execute
result = content_crew.kickoff(inputs={"topic": "AI Agents in 2025"})
print(result)

Why CrewAI? - Natural role-based structure - Sequential task delegation - Each agent has specialized role - Team collaboration metaphor fits

Example 4: RAG Chatbot (LangChain)

Scenario: Conversational chatbot with memory and RAG

from langchain_aws import ChatBedrock, AmazonKnowledgeBasesRetriever
from langchain.chains import ConversationalRetrievalChain
from langchain.memory import ConversationBufferMemory

# Initialize components
llm = ChatBedrock(
    model_id="anthropic.claude-3-sonnet-20240229-v1:0",
    model_kwargs={"temperature": 0.7}
)

retriever = AmazonKnowledgeBasesRetriever(
    knowledge_base_id="KB123456",
    retrieval_config={
        "vectorSearchConfiguration": {
            "numberOfResults": 5
        }
    }
)

memory = ConversationBufferMemory(
    memory_key="chat_history",
    return_messages=True,
    output_key="answer"
)

# Create conversational RAG chain
qa_chain = ConversationalRetrievalChain.from_llm(
    llm=llm,
    retriever=retriever,
    memory=memory,
    return_source_documents=True,
    verbose=True
)

# Multi-turn conversation
print("Chatbot: Hello! How can I help you today?")

while True:
    user_input = input("You: ")
    if user_input.lower() in ['exit', 'quit']:
        break

    response = qa_chain({"question": user_input})
    print(f"Chatbot: {response['answer']}")

    # Show sources
    if response.get('source_documents'):
        print("\nSources:")
        for doc in response['source_documents'][:2]:
            print(f"- {doc.metadata.get('source', 'Unknown')}")

Why LangChain? - Excellent RAG support - Built-in memory management - Bedrock KB integration - Mature conversational chains

Example 5: Code Review System (AutoGen)

Scenario: Multi-agent code review with execution

import autogen

# Configure Bedrock
config_list = [{
    "model": "anthropic.claude-3-sonnet-20240229-v1:0",
    "api_type": "bedrock",
    "region_name": "us-east-1"
}]

# Create agents
developer = autogen.AssistantAgent(
    name="Developer",
    system_message="You are a Python developer. Write clean, efficient code.",
    llm_config={"config_list": config_list}
)

reviewer = autogen.AssistantAgent(
    name="CodeReviewer",
    system_message="""You are a code reviewer. Check for:
    - Bugs and errors
    - Performance issues
    - Security vulnerabilities
    - Best practices""",
    llm_config={"config_list": config_list}
)

executor = autogen.UserProxyAgent(
    name="Executor",
    human_input_mode="NEVER",
    code_execution_config={
        "work_dir": "code_review",
        "use_docker": False
    }
)

# Group chat for collaboration
groupchat = autogen.GroupChat(
    agents=[developer, reviewer, executor],
    messages=[],
    max_round=12
)

manager = autogen.GroupChatManager(
    groupchat=groupchat,
    llm_config={"config_list": config_list}
)

# Start code review process
executor.initiate_chat(
    manager,
    message="""Create a Python function to validate email addresses.
    Include error handling and unit tests."""
)

Why AutoGen? - Multi-agent conversation needed - Code execution capability - Collaborative problem-solving - Iterative review process

Summary

Quick Reference

Need	Framework	Reason
Simplest setup	Strands	Minimal code, AWS-native
Complex workflows	LangGraph	State machines, branching
Multi-agent teams	CrewAI	Role-based, intuitive
RAG application	LangChain	Best RAG support
Agent conversations	AutoGen	Multi-agent dialogue
AWS Bedrock-first	Strands or LangChain	Native integration
Maximum control	LangGraph	Explicit workflow control
Quick prototype	Strands	Fastest to implement

Installation Commands

# Strands
pip install strands-agents boto3

# LangGraph
pip install langgraph langchain-aws

# CrewAI
pip install crewai crewai-tools langchain-aws

# LangChain
pip install langchain langchain-aws boto3

# AutoGen
pip install pyautogen boto3

Key Takeaways

Start Simple: Begin with Strands or LangChain for most use cases
AWS Integration: Strands and LangChain have the best Bedrock support
Complexity Matters: Use LangGraph only when you need complex workflows
Team Structure: CrewAI excels when your problem maps to roles
Experimentation: AutoGen is great for research and exploration
Production Ready: LangChain and Strands are most production-ready
Community: LangChain has the largest community and resources
Cost Optimization: All frameworks support multiple Bedrock models for cost control

Resources

Official Documentation: - Strands Agents - LangGraph - CrewAI - LangChain - AutoGen

AWS Resources: - Amazon Bedrock Documentation - Bedrock Agents - Bedrock Knowledge Bases

Community: - LangChain Discord - CrewAI Discord - AWS re:Post

Content rephrased for compliance with licensing restrictions. Information synthesized from official documentation and AWS blog posts.

Sources: - AWS Blog: Build multi-agent systems with LangGraph and Amazon Bedrock - AWS Blog: Build agentic systems with CrewAI and Amazon Bedrock - Glama AI: AWS Strands Agents SDK - LangFuse: Comparing Open-Source AI Agent Frameworks

Python AI Agent Frameworks Guide

Table of Contents

Overview

Framework Comparison Matrix

Key Characteristics

Strands Agents

Philosophy

Core Characteristics

Architecture

AWS Bedrock Integration

Use Cases

Example: Customer Support Agent

LangGraph

Philosophy

Core Characteristics

Architecture

AWS Bedrock Integration

Use Cases

CrewAI

Philosophy

Core Characteristics

Architecture

AWS Bedrock Integration

Use Cases

LangChain

Philosophy

Core Characteristics

Architecture

AWS Bedrock Integration

Use Cases

AutoGen

Philosophy

Core Characteristics

Architecture

AWS Bedrock Integration

Use Cases

AWS Bedrock Integration

Bedrock-Specific Considerations

Common Bedrock Patterns

Non-Bedrock AWS Services Integration

Choosing the Right Framework

Decision Matrix

Use Case Recommendations

Complexity vs Control Trade-off

Team Skill Level Considerations

Implementation Examples

Example 1: Customer Support Agent (Strands)

Example 2: Document Analysis Pipeline (LangGraph)

Example 3: Content Creation Team (CrewAI)

Example 4: RAG Chatbot (LangChain)

Example 5: Code Review System (AutoGen)

Summary

Quick Reference

Installation Commands

Key Takeaways

Resources