kitio.aiMicrosoft Agent Framework vs Letta
A side-by-side look at pricing plans, free tiers, features, pros and cons, updated for 2026. Microsoft Agent Framework is completely free, while Letta is freemium.
At a glance
Best for
Pricing model
Starting price
Free plan
Made by
Based in
Rating
Key features
- Python and .NET SDKs
- Graph-based workflows
- Multi-agent orchestration
- Checkpointing
- OpenTelemetry tracing
- Persistent agent memory
- Agent SDK and API
- Agent Development Environment
- Cloud or self-hosted
- Agent export and import
| Feature | Microsoft Agent Framework | Letta |
|---|---|---|
| Best for | Microsoft's open-source successor to AutoGen and Semantic Kernel | Platform for stateful AI agents with long-term memory |
| Category | Agents & automation | Agents & automation |
| Pricing model | Free | Freemium |
| Starting price | Free | $20/mo |
| Free plan | Yes, fully free | Yes |
| Made by | Microsoft | Letta |
| Based in | United States | United States |
| Rating | No ratings yet | No ratings yet |
| Key features |
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Pricing compared
Microsoft Agent Framework is completely free, while Letta is freemium.
Free plan
Cheapest paid plan
Top plan
Free trial
5 plans
Free
Free
- Limited stateful agents
- 5 MiB storage per memory repo
- Bring your own API keys
Pro
$20/mo
- Up to 20 stateful agents
- Letta Auto weekly + monthly quota
- 50 MiB storage per memory repo
Teams Pro
$20/mo
- Per seat
- Share agents with access control
- All Pro features
API Plan
$0.10 / active agent / mo
- Unlimited agents
- $0.00015 per sec tool execution
- Pay-as-you-go LLM usage
Enterprise
Contact sales
- Role-based access control
- SAML/OIDC SSO
- Dedicated support
Prices in USD, checked Oct 28, 2026 or later. Plans change often, so confirm on each tool's site before you buy.
Pros and cons
Microsoft Agent Framework
- Supported long term by Microsoft
- First-class .NET support
- Combines AutoGen and Semantic Kernel
- Migration from older SDKs takes work
- Best fit with Azure services
Letta
- Strong long-term memory design
- Open-source core
- Clear view of agent state
- Developer-focused
- Free plan limited to a few agents
Which one should you choose?
Choose Microsoft Agent Framework if you want:
- Supported long term by Microsoft
- First-class .NET support
- Combines AutoGen and Semantic Kernel
Watch out: migration from older sdks takes work.
Choose Letta if you want:
- Strong long-term memory design
- Open-source core
- Clear view of agent state
Watch out: developer-focused.
Microsoft Agent Framework vs Letta FAQ
What is the difference between Microsoft Agent Framework and Letta?
Microsoft Agent Framework: Microsoft's open-source successor to AutoGen and Semantic Kernel. Letta: Platform for stateful AI agents with long-term memory. Both are agents & automation tools.
Is Microsoft Agent Framework or Letta cheaper?
Microsoft Agent Framework is completely free, while Letta is freemium.
Do Microsoft Agent Framework and Letta have free plans?
Microsoft Agent Framework: Yes, fully free. Letta: Yes.
Who makes Microsoft Agent Framework?
Microsoft Agent Framework is made by Microsoft, based in United States.
Who makes Letta?
Letta is made by Letta, based in United States.
Which should I choose, Microsoft Agent Framework or Letta?
Choose Microsoft Agent Framework if you value supported long term by microsoft and first-class .net support. Choose Letta if you value strong long-term memory design and open-source core.