Microsoft Agent Framework is an open (MIT) runtime for building, orchestrating and deploying single and multi-agent AI workflows across both Python and .NET.
Yes, Microsoft Agent Framework is open source under the MIT license.
Microsoft Agent Framework is free to use.
Yes, Microsoft Agent Framework can be self-hosted (the source is available under the MIT license).
Microsoft Agent Framework is an open (MIT) framework for building, orchestrating, and deploying AI agents and multi-agent workflows, with first-class support for both Python and .NET. Open source: yes (MIT); self-hostable; free OSS. It has ~13.9k stars, ~3,400+ commits, is actively developed, and comes from the microsoft org.
Agent Framework gives developers the primitives to build an agent and then compose several into a workflow: defining agents, wiring their tools, and orchestrating how they hand work between each other. The notable part is the dual runtime. Most agent frameworks are Python-first and leave .NET shops to improvise, while this one supports Python and .NET as first-class targets, which matters for the many GTM and enterprise systems that live in the .NET world. It is MIT-licensed and self-hostable, so you run it on your own infrastructure rather than inside a vendor's agent product. Open source: yes (MIT); self-hostable; free OSS.
If you are building agents into a GTM stack rather than buying one, the framework underneath is a long-lived decision, and this is a credible, permissively-licensed option with unusually strong .NET support. For a team whose CRM, billing, or internal tooling already runs on .NET, a framework that treats .NET as first-class (not a port) removes real friction, and MIT plus self-hosting keeps the agents and their data on your infrastructure. The honest read: it is a framework, not a finished agent, so there is build work and ongoing maintenance, and because it is young and fast-moving you should pin versions and expect churn. It is also a Microsoft project, so sanity-check whether a given integration path leans on Azure or Microsoft services before you assume it is neutral.