175 listed
Harnesses & SDKs
Frameworks and SDKs for building agents: the Claude Agent SDK, OpenAI Agents SDK, LangGraph, CrewAI and many more. Each page lists languages, packages, MCP and A2A support and how it orchestrates agents, with a link to the page every fact came from.
Showing 25–48 of 175
| Name | Language | Stars | Downloads / month (approx.) | MCP | A2A | Multi-agent |
|---|---|---|---|---|---|---|
| CrewAI Open-source Python framework for multi-agent workflows, with role-based Crews and event-driven Flows. | Python | 60.1K | ~2.8M | Not stated | Not stated | Yes |
| stagehand SDK for browser agents with act, observe and extract calls, used from TypeScript and Python to automate sites and pull out structured data. | TypeScript, Python, Go | 25.8K | ~4.3M | Not stated | Not stated | — |
| Claude Agent SDK (Python) Python SDK that runs the Claude Code agent loop inside your own program, with custom tools and hooks written as Python functions. | Python | 8.3K | ~34M | Built in | Not stated | — |
| Agent Squad Open-source framework that routes each user query to one of several AI agents, with Python, TypeScript and Swift runtimes. | Python, TypeScript, swift | 7.8K | ~6.5K | Built in | Not stated | Yes |
| Agno Python framework and runtime for building agents, serving them over a REST API and MCP server, and managing them from a web control plane. | Python | 42.9K | ~2.2M | Built in | Built in | Yes |
| Vercel AI SDK TypeScript toolkit for AI apps and agents with a unified provider API, streaming, UI hooks and a wrapper for running established agent harnesses. | TypeScript | 27.5K | — | Not stated | Not stated | — |
| LiveKit Agents Framework for Python or Node.js programs that join LiveKit rooms as realtime voice and video agents. | Python, JavaScript | 14.9K | ~4.1M | Built in | Not stated | — |
| LangGraph.js Open-source agent harness from LangChain for building agents with code, with LangSmith for testing and monitoring. | TypeScript | 3.4K | ~10M | Not stated | Not stated | — |
| Pipecat Open-source Python framework for real-time voice and multimodal agents, built from composable pipelines with handoffs between specialist agents. | Python | 16.8K | ~1.6M | Not stated | Not stated | Yes |
| LangChain.js JavaScript and TypeScript framework of interoperable components for building LLM apps and agents, with LangGraph.js and Deep Agents above it. | TypeScript, JavaScript | 18.3K | — | Not stated | Not stated | — |
| Claude Agent SDK (TypeScript) TypeScript SDK that gives programs Claude Code's built-in tools for reading, editing and running code, installed from npm. | TypeScript | 1.8K | ~34.6M | Not stated | Not stated | — |
| Haystack Open-source Python framework from deepset for modular pipelines and agent workflows covering retrieval, tool use and generation. | Python | 26.8K | ~622.8K | Not stated | Not stated | — |
| Hugging Face smolagents Small Python library whose agents write their actions as code, with sandboxed execution and tools from MCP servers, LangChain or the Hub. | Python | 30K | ~595.5K | Built in | Not stated | — |
| trigger.dev TypeScript platform to build and deploy long-running AI agents and workflows with retries, queues and human approval steps. | TypeScript, JavaScript | 16.6K | — | Not stated | Not stated | — |
| docx-editor Browser DOCX editor and document engine built on OOXML, with a Document API that agents reach through SDKs, a CLI and an MCP server. | JavaScript, Python | 1.1K | — | Via adapter | Not stated | — |
| Coinbase AgentKit Coinbase toolkit that gives AI agents a crypto wallet and onchain actions, framework- and wallet-agnostic. | JavaScript, Python | 1.3K | ~7.9K | Not stated | Not stated | — |
| Eino Go framework for LLM applications with chat-model agents, multi-agent coordination, graph workflows and human-in-the-loop resume. | Go | 13.4K | — | Not stated | Not stated | Yes |
| LangChain4j Java library with one API over LLM providers and vector stores, plus tools, RAG and integrations for Quarkus and Spring Boot. | Java | 13.3K | — | Not stated | Not stated | — |
| Spring AI Alibaba Java framework for agentic, workflow and multi-agent AI apps, with graph workflows, MCP and A2A support. | Java | 11.1K | — | Built in | Built in | Yes |
| AgentScope Python agent framework from Alibaba that lets the model drive tool use, with team pipelines, MCP, agent skills, A2A, memory and tracing. | Python | 33.8K | ~218.1K | Built in | Built in | Yes |
| VoltAgent TypeScript framework for AI agents with tools, memory, RAG, MCP and sub-agents, paired with a Cloud or self-hosted console. | TypeScript | 10.9K | — | Built in | Not stated | Yes |
| PageIndex Python library that builds a tree index of long documents and has an LLM reason through it to retrieve answers, without a vector database or chunking. | Python | 39.6K | ~186.8K | Not stated | Not stated | — |
| Agently AI application runtime framework for backends with structured outputs, observable actions, MCP capabilities and recoverable workflows. | Python | 1.7K | ~2.9K | Built in | Not stated | — |
| Active Agent Rails framework for building AI agents as controllers, with provider gems for OpenAI, Anthropic, Ollama and more. | ruby | 985 | — | Not stated | Not stated | — |