Comparison
Best AI agent frameworks (Nov 2026): 19 compared, free and open source
There is no single best AI agent framework. This page compares 19 free and open-source frameworks and SDKs. The licence and the latest GitHub release were read on November 9, 2026. The code is free to use under the licence named here. Calls to a hosted model are billed by that provider, not by the framework.
Last verified November 9, 2026. Cells are the licence and the latest GitHub release read on November 9, 2026. This is not a quality ranking.
Key takeaways
- There is no single best AI agent framework. This page compares 19 repositories, not a scored ranking.
- The code is free and open source under the licence in the table. A hosted model the framework calls is a separate bill.
- Release tags were read from GitHub on November 9, 2026. CrewAI 1.15.39 and the Vercel AI SDK tag @ai-sdk/vue@3.0.326 were published that day.
Last verified November 9, 2026
What are the best AI agent frameworks in November 2026?
There is no single best AI agent framework. This page compares 19 free and open-source frameworks and SDKs. The licence and the latest GitHub release were read on November 9, 2026.
The code is free to use under the licence in the table. A hosted model the framework calls is a separate bill. The workshop around a model, as opposed to the library, is What is an AI agent harness? The priced coding products are Best AI coding agents. The shelf for every table is Best AI agents. The harness guides sit on Agent harnesses.
Which AI agent frameworks are free and open source?
All 19 are free and open source under the licence GitHub or the licence file named. MIT covers LangChain, LangGraph, CrewAI, Microsoft Agent Framework, Semantic Kernel, the OpenAI Agents SDK, the Claude Agent SDK’s Python package, LlamaIndex, Pydantic AI, and DSPy. Apache-2.0 covers Google ADK, smolagents, Agno, CAMEL, Letta, Haystack, and the Vercel AI SDK. AutoGen is CC-BY-4.0. Mastra is Apache-2.0 outside an ee/ tree that the licence file licenses separately.
Open source here means the repository’s code licence, not a free hosted agent. The November 5 snapshot of the same repositories is the framework release report. This page re-read the tags on November 9 and does not copy that day’s star counts.
How do these AI agent frameworks compare on licence and release?
Nineteen repositories. The release column is the tag GitHub’s latest-release endpoint returned on November 9, 2026. In a monorepo that tag can be one package.
Sort any column. A blank would mean the official page did not state the fact. Source numbers match the list at the end of the page. Last verified November 9, 2026. The shelf for this table is Best AI agents.
- LangChain
- LangGraph
- CrewAI
- AutoGen
- Microsoft Agent Framework
- Semantic Kernel
- OpenAI Agents SDK
- Google ADK
- Claude Agent SDK
- smolagents
- LlamaIndex
- Pydantic AI
- Mastra
- Agno
- DSPy
- CAMEL
- Letta
- Haystack
- Vercel AI SDK
| Agno | agno-agi/agno | A self-hosted agent platform | Apache-2.0 | v3.1.12 on October 29, 2026 | Python | [1] |
| AutoGen | microsoft/autogen | An older Microsoft agent framework | CC-BY-4.0 | python-v0.7.5 on September 30, 2025 | Python | [1] |
| CAMEL | camel-ai/camel | Multi-agent research code | Apache-2.0 | v0.2.90 on March 22, 2026 | Python | [1] |
| Claude Agent SDK | anthropics/claude-agent-sdk-python | Claude Code’s loop as a library | MIT | v0.2.179 on November 6, 2026 | Python | [1] |
| CrewAI | crewAIInc/crewAI | Role-based multi-agent code | MIT | 1.15.39 on November 9, 2026 | Python | [1] |
| DSPy | stanfordnlp/dspy | Programming a model instead of only prompting | MIT | 3.4.1 on October 12, 2026 | Python | [1] |
| Google ADK | google/adk-python | Code-first Python agents | Apache-2.0 | v2.14.0 on November 7, 2026 | Python | [1] |
| Haystack | deepset-ai/haystack | Pipelines and agent workflows | Apache-2.0 | v3.4.1 on October 21, 2026 | Python | [1] |
| LangChain | langchain-ai/langchain | Agent engineering libraries | MIT | langchain-core==1.7.6 on November 5, 2026 | Python | [1] |
| LangGraph | langchain-ai/langgraph | Graph-style agent runs | MIT | sdk==0.4.14 (langgraph-sdk) on November 6, 2026 | Python | [1] |
| Letta | letta-ai/letta | Agents with stored memory | Apache-2.0 | 0.16.8 on May 14, 2026 | Not detected by GitHub | [1] |
| LlamaIndex | run-llama/llama_index | Document pipelines that can call agents | MIT | v0.14.25 on September 21, 2026 | Python | [1] |
| Mastra | mastra-ai/mastra | A TypeScript agent framework | Apache-2.0 outside ee/; ee/ is separate | @mastra/core@1.82.0 on November 4, 2026 | TypeScript | [1] [2] |
| Microsoft Agent Framework | microsoft/agent-framework | Python and .NET agent workflows | MIT | python-1.25.0 on November 7, 2026 | Python | [1] |
| OpenAI Agents SDK | openai/openai-agents-python | A lightweight multi-agent loop | MIT | v0.24.0 on October 15, 2026 | Python | [1] |
| Pydantic AI | pydantic/pydantic-ai | Typed Python agents | MIT | v2.66.0 on November 4, 2026 | Python | [1] |
| Semantic Kernel | microsoft/semantic-kernel | Adding a model to an existing app | MIT | dotnet-1.82.0 on November 7, 2026 | C# | [1] |
| smolagents | huggingface/smolagents | A small code-writing agent library | Apache-2.0 | v1.26.0 on May 29, 2026 | Python | [1] |
| Vercel AI SDK | vercel/ai | TypeScript apps that call models and agents | Apache-2.0 (from the LICENSE file) | @ai-sdk/vue@3.0.326 on November 9, 2026 | TypeScript | [1] [3] |
Which AI agent framework fits which job?
These are job-fit notes from the repository description and the release tag. They are not scores.
These are job-fit notes from the documented scope, not scores.
Best for a Python loop you embed
The OpenAI Agents SDK, the Claude Agent SDK, and Pydantic AI are libraries you run in your own process. They are not a finished chat product.
Best for a graph of steps
LangGraph’s repository description is “Build resilient agents.” The latest tag on November 9, 2026 was langgraph-sdk 0.4.14, published November 6.
Best for role-based multi-agent code
CrewAI’s repository describes a framework for role-playing agents. The latest release that day was 1.15.39, published November 9, 2026.
Best for TypeScript
Mastra’s repository calls itself a TypeScript framework for AI applications and agents. The Vercel AI SDK repository calls itself an AI toolkit for TypeScript. Both are in the table.
How were these AI agent framework releases checked?
On November 9, 2026, each row was read from the public GitHub repository endpoint and /releases/latest. Nothing in the table is estimated.
A latest-release tag in a monorepo can name one package, such as a Vue package or an SDK package, rather than every package in the repository. Licences are the SPDX id GitHub returned, except Mastra and the Vercel AI SDK, where GitHub returned no SPDX id and the licence file on the default branch was read the same day. This page does not invent ratings or a composite score.
What else do people ask about AI agent frameworks?
Short answers on count, price, and how this list relates to the November 5 snapshot.
How many AI agent frameworks does this page compare?
It compares 19 open-source frameworks and SDKs. The set matches the repositories in this site’s November framework snapshot, with licences and release tags re-read from GitHub on November 9, 2026.
Are these AI agent frameworks free and open source?
The code is free under the licence in the table. MIT, Apache-2.0, and CC-BY-4.0 are the SPDX ids GitHub returned, with two licence files read by hand where GitHub returned no SPDX id. A model API the framework calls is not free just because the library is.
Which AI agent framework had a GitHub release on November 9, 2026?
CrewAI 1.15.39 and the Vercel AI SDK tag @ai-sdk/vue@3.0.326 were published on November 9, 2026. The other rows’ latest tags are older.
Is the latest GitHub tag the version of the whole framework?
Not always. GitHub’s latest-release endpoint returns one tag. In LangGraph, Mastra, Semantic Kernel, and the Vercel AI SDK, that tag names a package inside the repository.
Sources
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Citation
AI Agents Info. "Best AI agent frameworks." Last verified November 9, 2026. https://www.aiagentsinfo.com/best/ai-agent-frameworks.
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<blockquote cite="https://www.aiagentsinfo.com/best/ai-agent-frameworks"> <p>There is no single best AI agent framework. This page compares 19 free and open-source frameworks and SDKs. The licence and the latest GitHub release were read on November 9, 2026. The code is free to use under the licence named here. Calls to a hosted model are billed by that provider, not by the framework.</p> <footer><a href="https://www.aiagentsinfo.com/best/ai-agent-frameworks">Best AI agent frameworks</a>, AI Agents Info, last verified November 9, 2026.</footer> </blockquote>