--- title: "AutoGen vs Letta: Which is Better in 2026? | App Stack Builder" description: "AutoGen vs Letta compared for 2026 — pricing, free tiers, features, pros & cons. See which agent framework tool is the better fit for your startup." source: https://appstackbuilder.com/compare/autogen-vs-letta retrieved: 2026-10-29 --- ![](https://www.google.com/s2/favicons?domain=microsoft.github.io&sz=128) vs ![](https://appstackbuilder.com/logos/letta.png) # AutoGen vs Letta: Which is Better in 2026? Agent Framework Choosing between [AutoGen](https://appstackbuilder.com/tools/autogen) and [Letta](https://appstackbuilder.com/tools/letta)? Both are popular agent framework tools. Below we compare them on pricing, free tiers, features, and pros & cons so you can pick the right fit for your stack. AutoGen is for: Teams that already run AutoGen and need to maintain it while they plan a move to Microsoft Agent Framework. Letta is for: Teams building agents that must remember users and context across sessions and restarts, with memory as the core design. Quick verdict There’s no single winner; pick on your constraint. Choose AutoGen if you already run AutoGen in production and need it to keep working while you migrate. Choose Letta if your agent must remember users and past sessions over weeks or months. ## AutoGen vs Letta — Side by Side | | AutoGen | Letta | | --------------------- | ----------------------------------------------------------- | ------------------------------------------------------------------------ | | Category | Agent Framework | Agent Framework | | What it is | Code library: multi-agent conversation framework | Agent server and SDKs: agents with persistent memory | | Languages | Python, .NET | Python and TypeScript SDKs | | Licence | MIT (code) | Apache 2.0 | | Managed / paid option | None | Letta API: free tier, Pro $20/month plus usage | | Project status | Maintenance mode; successor is Microsoft Agent Framework | Active | | Pricing | Free | Free · paid from $20/mo | | Starting price | Free tier available | Free tier available | | Free tier | ✓ | ✓ | | Rating | 4.4 | 4.0 | | Best for | Agent Framework — existing AutoGen projects, migration path | Agent Framework — long-term memory, stateful agents, self-host or hosted | ## Pros & Cons ![](https://www.google.com/s2/favicons?domain=microsoft.github.io&sz=128) [AutoGen](https://appstackbuilder.com/tools/autogen) * ✓Backed by Microsoft Research * ✓Strong multi-agent conversation model * ✓Completely free * ✓Active development * ✗APIs have shifted between versions * ✗Python-centric ![](https://appstackbuilder.com/logos/letta.png) [Letta](https://appstackbuilder.com/tools/letta) * ✓Memory is the design centre, not an add-on * ✓Agents survive restarts with state intact * ✓Comes from the MemGPT paper * ✗Younger project with a moving API * ✗Memory model is opinionated ## Key Features Compared ### AutoGen * ✓Multi-agent conversations and group-chat orchestration * ✓Python and .NET libraries * ✓In maintenance mode: bug fixes, security patches and docs only, community-managed * ✓Microsoft Agent Framework 1.0 (April 2026) is the successor, with a migration guide * ✓AG2 is a separate community fork led by AutoGen’s original creators ### Letta * ✓Persistent, self-editing agent memory (from the MemGPT research) * ✓Agents keep their state across restarts * ✓Self-hosted server, or the hosted Letta API * ✓Hosted plans: free tier and Pro at $20 a month with pay-as-you-go usage * ✓Letta Code, an open-source coding agent with memory across sessions * ✓Apache 2.0 licence ### Choose AutoGen if… * ✓You already run AutoGen in production and need it to keep working while you migrate. * ✓You’re studying multi-agent conversation patterns from the original research project. [AutoGen review & pricing ](https://appstackbuilder.com/tools/autogen) ### Choose Letta if… * ✓Your agent must remember users and past sessions over weeks or months. * ✓You want agents that keep state when the process restarts. * ✓You want the choice of self-hosting or a hosted API. [Letta review & pricing ](https://appstackbuilder.com/tools/letta) ## Frequently Asked Questions Is AutoGen better than Letta?⌄ There’s no single winner; pick on your constraint. Choose AutoGen if you already run AutoGen in production and need it to keep working while you migrate. Choose Letta if your agent must remember users and past sessions over weeks or months. What is the difference between AutoGen and Letta?⌄ What it is — AutoGen: Code library: multi-agent conversation framework. Letta: Agent server and SDKs: agents with persistent memory. Languages — AutoGen: Python, .NET. Letta: Python and TypeScript SDKs. Licence — AutoGen: MIT (code). Letta: Apache 2.0\. Managed / paid option — AutoGen: None. Letta: Letta API: free tier, Pro $20/month plus usage. Project status — AutoGen: Maintenance mode; successor is Microsoft Agent Framework. Letta: Active. AutoGen vs Letta: which is cheaper?⌄ AutoGen pricing: Free. Letta pricing: Free · paid from $20/mo. Confirm current pricing on each tool's official site, as plans change. Which is rated higher, AutoGen or Letta?⌄ In our catalog, AutoGen rates 4.4 out of 5 and Letta rates 4.0 out of 5, so AutoGen has a slight edge on reviews. When should I skip both AutoGen and Letta?⌄ Skip AutoGen if you’re starting a new project. AutoGen gets no new features; Microsoft points new work to Microsoft Agent Framework. Skip Letta if you only need short-lived task agents. A lighter SDK is simpler. Sources · tool facts checked October 2026 1. 1.[AutoGen repository and maintenance notice (GitHub)github.com ](https://github.com/microsoft/autogen) 2. 2.[AutoGen to Microsoft Agent Framework migration guide (Microsoft Learn)learn.microsoft.com ](https://learn.microsoft.com/en-us/agent-framework/migration-guide/from-autogen/) 3. 3.[Letta Code (Letta docs)docs.letta.com ](https://docs.letta.com/letta-code) See more options in our guide to the [best agent framework tools for startups](https://appstackbuilder.com/categories/agent-framework). ## Still not sure which to pick? Get a free, AI-powered tech stack — including the best agent framework pick for your budget and team — in 60 seconds. [Build my stack free ](https://appstackbuilder.com/build-stack)