<<< Previous Chapter Next Chapter >>>
From The Book: Agentic AI - Theories and Practices (Ken Huang, 2025, Springer)
A practical, no-nonsense guide for builders, not theorists
Introduction: The Most Common Mistake People Make
If you’ve started exploring Agentic AI, chances are you’ve already asked (or Googled):
“Should I use LangChain, AutoGen, LangGraph, LlamaIndex, or AutoGPT?”
And if you’re being honest, you probably hoped there was a single best answer.
Here’s the uncomfortable truth—straight from the chapter:
There is no “best” agent framework.
There is only a best fit for your problem.
Choosing an Agentic AI framework too early—or for the wrong reasons—is one of the fastest ways to:
-
build something impressive but unusable,
-
burn money on infrastructure,
-
or end up with an agent that works in demos and fails in production.
This post will help you avoid that.
Instead of starting with tools, we’ll start with how agents actually work, then map that understanding to framework choices in a simple, human way.
First: What an Agent Framework Actually Does (In Plain English)
Before picking a framework, let’s clear up a common misunderstanding.
An agent framework is not the AI model.
The model (like GPT-4 or Claude) is the brain.
The framework is the nervous system.
An agent framework decides:
-
how the agent thinks step by step,
-
how it remembers things,
-
how it uses tools,
-
how it loops, retries, or stops,
-
how failures are handled,
-
how multiple agents coordinate (if needed).
If you skip the framework layer, you’ll end up stuffing everything into prompts—and that never ends well.
The Big Mental Model: Don’t Pick a Framework in Isolation
Chapter 2 introduces a Seven-Layer AI Agent Architecture, and this is the most important idea to understand before choosing any framework.
In simple terms:
-
Frameworks live in Layer 3
-
They depend heavily on:
-
your data setup (Layer 2),
-
your deployment needs (Layer 4),
-
your safety and evaluation requirements (Layers 5 & 6).
-
So framework choice is never a standalone decision.
Step 1: Start With the Problem, Not the Tool
Here’s the first rule the chapter quietly enforces:
❌ “LangChain is popular, so let’s use it”
✅ “What kind of agent are we actually building?”
Ask yourself (or your team) these questions first:
1. Is this a short task or a long-running workflow?
-
One-shot answers → simpler frameworks
-
Multi-step reasoning → structured frameworks
2. Does the agent need memory?
-
Just this conversation?
-
Or across sessions, days, or weeks?
3. Does the agent act, or only answer?
-
Answering questions → RAG-focused tools
-
Taking actions (code, APIs, systems) → stronger control needed
4. Is safety critical?
-
Finance, healthcare, enterprise → observability + control required
-
Hobby projects → flexibility is fine
5. Will this scale?
-
One user → almost anything works
-
Thousands of users → architecture matters more than features
Only after answering these should you look at frameworks.
Step 2: Understand the Four “Personalities” of Agent Frameworks
The chapter groups popular frameworks by design philosophy, even if it doesn’t explicitly say so.
Let’s translate that into human terms.
1️⃣ LangChain / LangGraph: “I Want Structure Without Losing Flexibility”
What it’s good at
LangChain is often the first framework people encounter—and for good reason:
-
huge ecosystem,
-
tons of integrations,
-
flexible building blocks.
LangGraph (built on LangChain) adds something critical:
-
explicit state and flow control.
Instead of hidden loops, you get:
-
nodes,
-
edges,
-
clear transitions.
Think of LangChain as:
“A powerful toolbox”
And LangGraph as:
“A blueprint with guardrails”
When to choose it
Use LangChain / LangGraph if:
-
you’re building custom workflows,
-
you need controlled loops,
-
debugging matters,
-
production readiness is important.
When to be careful
-
LangChain alone can become messy if overused
-
Too much flexibility = accidental complexity
Rule of thumb
๐ Start with LangChain for exploration
๐ Move to LangGraph when workflows stabilize
2️⃣ AutoGen: “I Want Multiple Agents to Collaborate”
AutoGen takes a very different approach.
Instead of one agent doing everything, it assumes:
-
multiple agents,
-
different roles,
-
conversations between them.
For example:
-
Planner agent
-
Code writer agent
-
Reviewer agent
-
User proxy agent
They talk to each other, negotiate, and solve problems collaboratively.
When AutoGen shines
Use AutoGen if:
-
tasks benefit from role separation,
-
collaboration improves outcomes,
-
you want human-in-the-loop workflows,
-
coding, research, or analysis is central.
Trade-offs
-
More moving parts
-
Harder debugging
-
Higher cost
-
Requires discipline
Rule of thumb
๐ Use AutoGen when the problem naturally feels like a team
3️⃣ LlamaIndex: “My Agent Is Only as Good as My Data”
LlamaIndex is not really about agents first.
It’s about data first.
It assumes your biggest problem is:
-
finding the right information,
-
at the right time,
-
in the right format.
And honestly?
For many real projects, that’s true.
Where LlamaIndex excels
-
Knowledge-heavy agents
-
Enterprise documents
-
Search, QA, summarization
-
Compliance and auditability
It offers:
-
connectors to data sources,
-
indexing strategies,
-
query engines,
-
RAG out of the box.
When to choose it
Use LlamaIndex if:
-
your agent’s value comes from retrieval accuracy,
-
you have lots of documents,
-
hallucinations are unacceptable.
Limitations
-
Less opinionated about agent control loops
-
You’ll combine it with other frameworks for actions
Rule of thumb
๐ If your agent “knows things” more than it “does things,” start here
4️⃣ AutoGPT-Style Frameworks: “Let the Agent Run on Its Own”
AutoGPT represents the extreme end of autonomy.
You give it:
-
a goal,
-
minimal guidance,
-
and it plans and executes by itself.
It has:
-
memory,
-
internet access,
-
code execution,
-
file handling.
Sounds amazing, right?
The reality
AutoGPT is:
-
powerful,
-
unpredictable,
-
hard to control,
-
risky in production.
The chapter is very cautious here—and for good reason.
When (and when not) to use it
Use AutoGPT-style frameworks if:
-
you’re experimenting,
-
you’re researching autonomy,
-
cost and predictability aren’t critical.
Avoid it if:
-
you need reliability,
-
safety matters,
-
users depend on it.
Rule of thumb
๐ Autonomy is exciting, but constraints win in production
Step 3: Match Frameworks to Common Project Types
Let’s make this concrete.
๐ง Knowledge Assistant (Docs, PDFs, Search)
Best fit:
-
LlamaIndex + LangGraph
Why:
-
strong retrieval,
-
controlled reasoning,
-
explainable answers.
๐ค Workflow Automation (APIs, Actions, Tools)
Best fit:
-
LangGraph
-
Possibly AutoGen for delegation
Why:
-
explicit control,
-
easier failure handling,
-
safer execution.
๐จ๐ป Coding / Research Agent
Best fit:
-
AutoGen
Why:
-
multi-agent collaboration,
-
critique loops,
-
role-based reasoning.
๐ Long-Running Autonomous Tasks
Best fit:
-
Carefully constrained AutoGPT-style agents
-
Or LangGraph with strict limits
Why:
-
autonomy needs guardrails.
๐งช Prototypes and Learning
Best fit:
-
LangChain
-
BabyAGI
Why:
-
fast iteration,
-
low setup cost.
Step 4: Don’t Ignore Evaluation, Security, and Cost
One of the strongest messages in Chapter 2 is this:
Framework choice is meaningless if you can’t observe, secure, or afford the agent.
Before finalizing a framework, ask:
Can I observe what the agent is doing?
-
Logs
-
Traces
-
Decision paths
Can I stop it when it misbehaves?
-
Timeouts
-
Budget limits
-
Step caps
Can I explain its decisions?
-
Especially important for enterprise use
Can I afford it at scale?
-
Token usage
-
Tool calls
-
Infrastructure costs
A “cool” agent that bankrupts you is not a success.
The Decision Tree (Simplified)
If you remember nothing else, remember this:
-
Data-heavy? → LlamaIndex
-
Workflow-heavy? → LangGraph
-
Collaboration-heavy? → AutoGen
-
Autonomy-heavy? → AutoGPT (with caution)
And most real systems:
combine more than one framework
Final Advice: Frameworks Will Change — Principles Won’t
The chapter ends with a subtle but powerful reminder:
Agent frameworks evolve fast.
New ones will appear.
Old ones will fade.
But the principles stay constant:
-
separation of concerns,
-
explicit state,
-
evaluation first,
-
safety by design,
-
cost awareness.
If you choose a framework that aligns with these principles, you’ll be able to adapt—even when the tools change.
Closing Thought
Choosing an Agentic AI framework is not about picking the most popular tool.
It’s about asking:
“What kind of intelligence am I building—and how much freedom should it have?”
Answer that honestly, and the right framework usually becomes obvious.

No comments:
Post a Comment