Microsoft Agent Framework adds AG-UI frontends, Foundry memory and resumable workflows

What Microsoft announced

Microsoft published an overview of recent Agent Framework updates on 24 September 2026. Microsoft Agent Framework is the company's open-source SDK for building agents and multi-agent workflows in .NET and Python. The post groups the changes around four needs: an interface users can interact with, memory beyond one conversation, a safe place to run code, and recovery when work is interrupted.

The first is AG-UI, an open, event-based protocol for streaming agent progress, tool activity and approvals to a frontend. The Python integration, which exposes an agent through a FastAPI endpoint, is a stable release. The .NET version for ASP.NET Core is in public preview and uses a new AG-UI .NET SDK built on Microsoft.Extensions.AI. Microsoft names CopilotKit and new Blazor AI components as compatible frontends. New Python channel packages also expose the same agent through OpenAI Responses, Telegram, A2A and MCP.

Memory, CodeAct and recovery

For memory, FoundryMemoryProvider connects an agent to a memory store in Foundry Agent Service. It retrieves relevant memories before each run and submits the conversation for asynchronous extraction afterwards, so recall is not immediate. Azure Cosmos DB remains an alternative through a Python preview provider with hybrid vector and full-text search.

CodeAct lets the model write one short program that chains several tool calls instead of choosing tools step by step. HyperlightCodeActProvider runs that generated code in a Hyperlight sandbox, while registered tools still run in the application with their own permissions. Microsoft's CodeAct walkthrough reports about 50% lower latency and more than 60% lower token use on its evaluated workload, and the post tells readers to treat those as workload-specific.

For long-running work, workflows hosted in Foundry Agent Service can enable resilient background execution. After a restart, the host reloads persisted state and the matching workflow checkpoint, and the client can reconnect to the response. Microsoft notes that an interrupted step may run again, so tools that send email or take payments should use idempotency keys.

Why it matters

Most agent frameworks cover the loop between model and tools. The gaps teams hit in production are elsewhere: showing progress to users, remembering across sessions, and not losing an hour of work when a container restarts. Microsoft is filling those gaps with Foundry-hosted services, which ties the most complete experience to Azure even though the framework itself is open source. The post is also candid about limits, including that a thread ID is not an access control and that the .NET and Python feature sets are not identical.

What to watch next

The Python packages in the examples install with --pre, and the Python 1.20.0 release on 2 October already redesigned Foundry hosting in a breaking change. Microsoft also says Foundry Toolkit support in VS Code will let developers reconnect to long-running agents. Other framework updates, such as Strands harness from AWS, are collected under AI Agents.

Questions people ask

Is AG-UI support in Microsoft Agent Framework production-ready?

The Python FastAPI integration is a stable release. The .NET ASP.NET Core hosting integration is in public preview, according to Microsoft's 24 September post.

Does resilient execution guarantee each step runs once?

No. Microsoft says an interrupted step may run again, so tools with external side effects should tolerate retries, for example with idempotency keys.

Does Microsoft Agent Framework need Azure?

The framework is open source and supports several model providers, but the memory provider and resilient hosting described in the post use Microsoft Foundry.

Sources

1. What's new in Microsoft Agent Framework: Interactive experiences, memory, and resilient execution (Microsoft, 24 Sep 2026)
2. Microsoft Agent Framework python-1.20.0 (Microsoft, 2 Oct 2026)
3. Microsoft Agent Framework repository (Microsoft, 28 Oct 2026)