Agent Frameworks
Libraries and SDKs for building AI agents and multi-agent systems.
| Tool | What it does | Platforms | Pricing |
|---|---|---|---|
| LangGraph | Low-level orchestration framework from LangChain for building stateful, multi-step agents as graphs, with persistence and human-in-the-loop support. | Python, TypeScript | Open source (MIT) |
| LangChain | Popular framework for building LLM applications and agents with composable chains, tools, retrievers and integrations. | Python, TypeScript | Open source (MIT) |
| CrewAI | Python framework for orchestrating role-playing, collaborative multi-agent "crews" with tasks and processes. | Python | Open source + paid platform |
| AutoGen | Microsoft's open-source framework for building multi-agent conversational applications. | Python, .NET | Open source |
| OpenAI Agents SDK | Lightweight OpenAI SDK for multi-agent workflows with handoffs, guardrails and tracing. | Python | Open source (MIT) |
| LlamaIndex | Data framework for connecting LLMs to your data, with agent and workflow abstractions for RAG-heavy agents. | Python, TypeScript | Open source + paid cloud |
| Semantic Kernel | Microsoft SDK for integrating LLMs into apps with plugins, planners and agent abstractions. | C#, Python, Java | Open source (MIT) |
| Pydantic AI | Agent framework from the Pydantic team focused on type-safe, structured outputs and dependency injection. | Python | Open source (MIT) |
| smolagents | Hugging Face's minimal library for agents that think and act in code. | Python | Open source (Apache-2.0) |
| Mastra | TypeScript agent framework with workflows, memory, RAG, evals and integrations. | TypeScript | Open source |
| Vercel AI SDK | TypeScript toolkit for building AI apps and agents with streaming, tool calling and multi-provider support. | TypeScript | Open source |
| Agno | Python framework (formerly Phidata) for building multi-modal agents with memory, knowledge and tools. | Python | Open source + paid platform |
| Haystack | deepset's open-source framework for production RAG pipelines and agents. | Python | Open source (Apache-2.0) |
| Google Agent Development Kit | Google's open-source toolkit for building, evaluating and deploying agents, optimized for Gemini. | Python, Java | Open source (Apache-2.0) |
| DSPy | Stanford framework for programming—rather than prompting—language models, with optimizers for prompts and weights. | Python | Open source (MIT) |
| CAMEL | Open-source multi-agent framework and research community studying agent societies. | Python | Open source |
| Letta | Framework (from the MemGPT team) for stateful agents with long-term memory. | Python | Open source + paid cloud |
| Claude Agent SDK | Anthropic's SDK for building agents on the same harness that powers Claude Code. | Python, TypeScript | Open source |