AI Agent Zero-to-Hero Tutorial
What tech stack do agent products actually use? This guide breaks down the complete tech stack behind mainstream AI agents. Build your mental map from zero.
Overview: The Six-Layer Agent Tech Stack
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| 6. Observability Tracing, debugging |
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| 5. Deployment Serve as API/UI |
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| 4. Low-Code Drag-and-drop |
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| 3. Tools & Proto Interact with world |
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| 2. Memory Short + long term |
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| 1. Orchestration Agent skeleton |
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| 0. LLM The brain |
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0. LLM Providers -- The Brain
Updated 2026-07-22.
Model
Provider
Positioning
Key Strengths
GPT-5.5
OpenAI
Flagship
Apr 2026; 1M context; built-in Computer Use / MCP / Web Search; GPT-5.5 Pro for harder problems
Claude Opus 4.8
Anthropic
Agent specialist
May 2026; best for coding + long-running agentic tasks; Fable 5 (Jun) even stronger but access-restricted
Claude Sonnet 4.6
Anthropic
Value pick
Feb 2026; speed + intelligence balanced; 1M context (Beta); daily agent go-to
Gemini 3.6 Flash
Google
Low-cost agents
Jul 22, 2026; 17% fewer tokens; optimized for large-scale agent workflows
Llama 4
Meta
Open-source
Local deployment; data stays on your machine
Note: GPT-4o, o3, o4-mini retired Feb 2026. Claude 3.5 also out of main lineup.
Model
Provider
Positioning
Key Strengths
DeepSeek V4-Pro
DeepSeek
Open-source flagship
Apr 2026; 1.6T params (MoE); 1M context; MIT license; Huawei Ascend native; ~1/10 GPT cost
Qwen 3.7-Max
Alibaba
CN #1
Arena blind-test leader among Chinese models; 100M+ downloads
GLM-5.2
Zhipu AI
Long-horizon agents
Jul 2026; million-token context; bi-monthly iteration; 6M+ global users
Kimi K2.6
Moonshot AI
Agent Swarm
Hundreds of sub-agents simultaneously; K2.5 does end-to-end software dev
MiniMax M3
MiniMax
Cost-breaker
Jun 2026; native multimodal; SWE-Bench Pro 59; ~1/5 Claude price
Wenxin 6.0
Baidu
Massive scale
2.4T params; 2M context; offline on mobile
Hunyuan Hy3
Tencent
Ecosystem
2.95B params (MoE); Apache 2.0; embedded in WeChat/Docs/Meetings
Baichuan M4
Baichuan
Medical
Medical-focused; AI family doctor; ultra-low hallucination
Note: DeepSeek R2 never shipped; reasoning absorbed into V4 Thinking mode.
Scenario
Recommendation
Prototype / learn agent dev
DeepSeek V4 (nearly free) or GPT-5.5
Coding agent
Claude Opus 4.8 or GPT-5.3-Codex
High-volume, cost-sensitive
Gemini 3.6 Flash or MiniMax M3
China-compliant production
Qwen 3.7 / GLM-5.2
Long-horizon multi-step
GLM-5.2 or Kimi K2.6
Air-gapped / data sovereignty
DeepSeek V4 (MIT) or Llama 4
Healthcare / legal vertical
Baichuan M4 or custom fine-tuned
1. Orchestration Frameworks -- The Skeleton
Framework
Language
Level
One-liner
Stars
LangChain
Python/JS
Entry
Swiss Army knife; largest ecosystem
100K+
LangGraph
Python/JS
Mid
State-machine agent flows; complex multi-step
10K+
LlamaIndex
Python/JS
Entry
Data-first; indexing & RAG expert
38K+
CrewAI
Python
Entry
Multi-agent teams with roles & goals
25K+
AutoGen
Python
Mid
Microsoft; conversational multi-agent; enterprise
38K+
Semantic Kernel
C#/Python/Java
Mid
Microsoft; deep Azure / .NET integration
22K+
Vercel AI SDK
TypeScript
Entry
Frontend-first; streaming UX; Next.js
12K+
Spring AI
Java
Entry
Java's LangChain; Spring Boot native
4K+
Haystack
Python
Entry
NLP pipeline; search/QA agents
18K+
MetaGPT
Python
Mid
Simulates software company SOP
50K+
Memory Type
What it is
Storage
Short-term
Current conversation
LLM context window
Long-term
History, preferences
Vector DB + SQL/NoSQL
Product
Type
One-liner
Chroma
Lightweight OSS
pip install and go; learning & prototypes
Milvus
Production OSS
China's most mature; trillion-scale
Qdrant
High-perf OSS
Rust-based; excellent single-node
Weaviate
Full-featured OSS
Built-in vectorization + hybrid search
Pinecone
Cloud
Zero-ops; pay-per-use
pgvector
PG extension
Already on Postgres? One extension
Elasticsearch
Search engine
8.0+ native vectors
3. Tools & Protocols -- Letting Agents Act
Mechanism
Origin
Description
Function Calling
OpenAI
Structured JSON output to call your functions
Tool Use
Anthropic
Define tools with name/description/schema
MCP
Anthropic
Industry standard -- "USB-C for agents"
Platform
Provider
Best for
Dify
OSS / CN
Visual workflows; built-in RAG; self-hosted
Coze (Kouzi)
ByteDance
Bot store; plugin market; WeChat/Douyin
FastGPT
OSS / CN
Knowledge-base Q&A; simple deploy
Alibaba Bailian
Alibaba Cloud
Qwen family; full pipeline
Baidu Qianfan
Baidu
Wenxin ecosystem
Flowise
OSS
Visual LangChain; drag-and-drop
n8n + AI
OSS
Automation + AI nodes
Mode
Tools
Best for
API service
LangServe, FastAPI
REST API wrapper
Chat UI
Chainlit, Gradio
Quick demo
Serverless
Cloudflare Workers, Vercel
Zero-ops; lightweight
Containers
Docker + K8s
Production standard
Embedded
Direct import
Module in existing project
Tool
One-liner
LangSmith
LangChain official; auto-records every call
LangFuse
Open-source alternative; self-hostable
Phoenix (Arize)
LLM observability; visual tracing
Weights & Biases
MLOps veteran; LLM tracking
Dimension
Method
Accuracy
Human / LLM-as-judge
Tool-call correctness
Audit right tool + right params
Latency
End-to-end (LLM + tools)
Cost
Token-usage tracking
Safety
Jailbreak / injection detection
I want to build...
Recommended stack
Personal AI assistant
GPT-5.5 / DeepSeek V4 + LangChain + Tavily
Enterprise knowledge QA
Dify or LlamaIndex + Milvus
Code review agent
Claude Opus 4.8 + GitHub API + LangChain
Multi-role writing team
CrewAI + Claude / DeepSeek
Data analyst agent
LangChain + Python REPL + Streamlit
Customer service system
LangGraph + PostgreSQL + MCP
Browser automation
Playwright + Claude/GPT (built-in Computer Use)
AI chat app frontend
Vercel AI SDK + Next.js
Java AI integration
Spring AI + model APIs
High-volume agents
Gemini 3.6 Flash + Dify / LangChain
Week 1: Call a model API
Week 2: First Function Calling with LangChain
Week 3: Add memory -- Chroma + RAG
Week 4: Learn MCP
Week 5: Deploy -- FastAPI or Dify
Week 6+: Multi-agent, fine-tuning, evaluation