AutoGen deserves credit for being early and thoughtful. When it appeared, most agent frameworks were thin wrappers over a chat completion call with a tool loop bolted on. AutoGen came out of Microsoft Research with an actual model of what multi agent conversation should look like, and the vocabulary it introduced, agents with roles, group chats, termination conditions, human in the loop participants, has influenced how everyone thinks about this. Reading the conceptual documentation is worthwhile even if you never write a line of AutoGen code.
The documentation structure reflects the framework's own layering. AgentChat is the high level API and where the tutorial starts, and it is the right entry point. You create an AssistantAgent, give it a model client and some tools, put a couple of agents in a RoundRobinGroupChat, set a termination condition, and you have a working multi agent system in a page of code. That path works and the examples run, which is not something I can say about every framework's getting started guide.
Underneath sits the core API, an event driven actor style layer that gives you real control over message routing and agent lifecycles. The idea of exposing both is good design. The execution is uneven, and documentation quality falls off noticeably once you go below AgentChat. The core API section reads more like reference material written by people who already understand the system than like teaching, and working out how to do something non standard means reading source and issues.
Now the thing that has to be said clearly, because it changes the recommendation. Microsoft has been consolidating its agent story, and the guidance now points new projects towards the Microsoft Agent Framework, with a published migration guide from AutoGen. AutoGen is not abandoned, and the ideas in it fed directly into the successor, but building something you intend to maintain on a framework whose own vendor is steering people elsewhere is a decision you should make deliberately rather than by accident. I would not tell someone starting a new production system in 2026 to reach for AutoGen without a specific reason.
The version history is its own warning. The 0.2 to 0.4 rewrite was substantial and broke compatibility, and the internet is still full of tutorials, blog posts and Stack Overflow answers written against the old API that will not run. If you search for an AutoGen example, check what version it targets before you spend an hour on it. The documentation handles this reasonably by versioning clearly, but the wider ecosystem does not.
Two practical gaps deserve mention. Debugging multi agent conversations is genuinely hard, because when three agents talk to each other and produce a wrong answer, working out which turn went wrong requires reading transcripts carefully, and the docs give you very little tooling or guidance for this. And there is almost nothing on cost. Multi agent systems are expensive in a way that surprises people, because every agent turn is a full context call, and a group chat that runs twenty turns has done twenty of those.
A section on controlling this would be more useful than another example. My 3.5 is a rating for solid documentation of a framework in an awkward position. The conceptual material is genuinely good and the ideas transfer to whatever you end up using. The tutorial works.
But the framework's own future is unclear enough that I cannot recommend committing to it, and the deeper documentation does not hold up to the quality of the introduction. Read it to learn how to think about agents. Choose your framework on other grounds.