Agent Frameworks & SDKs

OpenAI Agents SDK, Pydantic-AI, smolagents, Strands, and LangGraph — pick by what your agent needs.

The framework layer is where you actually wire a model to tools and get a working agent loop. Each of the five covered here optimizes for a different shape of the same problem — pick based on what your agent actually needs to do, not by star count.

Quick pick: OpenAI-first production loop → OpenAI Agents SDK; typed outputs and tests → Pydantic-AI; minimal Hugging Face stack → smolagents; AWS-native simplicity → Strands; explicit graphs and branching → LangGraph. See our Python AI SDKs comparison for a longer side-by-side.

OpenAI Agents SDK

Pydantic-AI

smolagents

Strands Agents SDK

LangGraph

YouTube learning

Core concepts from video walkthroughs:

Threads in the same domain as this chapter — go deeper on iHateReading without leaving the roadmap.

Python AI agent SDKs in 2026: OpenAI vs Pydantic-AI vs smolagents vs Strands cover

Python AI agent SDKs in 2026: OpenAI vs Pydantic-AI vs smolagents vs Strands

Same three-tool agent in four frameworks — pick by execution model and testing needs.

Agent harnessing: the part of building AI agents nobody talks about cover

Agent harnessing: the part of building AI agents nobody talks about

Loop, tools, memory, sandbox, and tracing live in your code — not the model weights.

Smallest AI Agent cover

Smallest AI Agent

Minimal file-reading agent to learn LLM tool loops without framework magic.

AI Agent cover

AI Agent

What agents are and how they differ from a single chat completion.