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 101
| Name | Language | Stars | Downloads / month (approx.) | MCP | A2A | Multi-agent |
|---|---|---|---|---|---|---|
| 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 |
| 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 | — |
| 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 |
| 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 | — |
| Amazon Bedrock AgentCore SDK Python SDK for deploying agents to Amazon Bedrock AgentCore, a managed runtime with memory, gateway, tools and observability. | Python | 780 | ~6.9M | Built in | Not stated | — |
| notte Browser infrastructure for AI agents: local and cloud Playwright-based browser sessions, scraping and deployable browser functions. | Python, JavaScript, TypeScript | 2K | ~2.6K | Via adapter | Not stated | — |
| Spring AI Java application framework from the Spring project with portable chat and embedding APIs, tool calling and vector stores. | Java | 9.6K | — | Not stated | Not stated | — |
| LiveKit Agents (Node.js) Node.js distribution of the LiveKit Agents framework for realtime voice agents in LiveKit rooms. | JavaScript | 949 | ~2.3M | Built in | Not stated | — |
| OpenAI Agents SDK Python SDK for multi-agent workflows with handoffs, guardrails, sessions and built-in tracing, usable with OpenAI and other LLMs. | Python | 30.3K | ~19.3M | Built in | Not stated | Yes |
| AG2 Open-source Python framework for AI agents that cooperate on tasks, with human-in-the-loop workflows and multi-agent patterns. | Python | 5K | ~170.3K | Not stated | Not stated | Yes |
| Koog Kotlin and Java framework for AI agents with tools, graph workflows, MCP, streaming and multiplatform targets. | Kotlin, Java | 4.6K | — | Built in | Not stated | — |
| nixtla Python SDK for TimeGPT, a time series foundation model for forecasting and anomaly detection. | Python | 4K | ~120.9K | Not stated | Not stated | — |
| OGX (formerly Llama Stack) OpenAI-compatible agentic API server for inference, vector stores, files and skills, on any model or infrastructure. | Python | 8.4K | ~60.7K | Built in | Not stated | — |
| judgeval Python SDK for tracing agents and scoring their traces with prompt-based judges, to find failures in production. | Python | 1.1K | ~332.9K | Not stated | Not stated | — |
| Embabel JVM framework for agentic flows that plan toward goals, mixing LLM calls with code and domain models, usable from Kotlin or Java. | Kotlin, Java | 4.5K | — | Not stated | Not stated | — |
| RubyLLM Ruby AI framework with one API for chat, tools, agents, streaming, embeddings and Rails integration across many providers. | ruby | 4.5K | — | Built in | Not stated | Yes |