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 1–24 of 58
| Name | Language | Stars | Downloads / month (approx.) | MCP | A2A | Multi-agent |
|---|---|---|---|---|---|---|
| LlamaIndex Open-source Python toolkit for RAG and agents over your own data, with event-driven workflows and 300+ integration packages. | Python | 52.6K | ~6M | Not stated | Not stated | — |
| Strands Agents Open-source Python and TypeScript SDK for model-driven agents, with tools, MCP, multi-agent patterns and streaming. | Python, TypeScript | 8.9K | ~38.1M | Built in | Not stated | Yes |
| CopilotKit Open-source SDK that connects AI agents to app front ends with chat UI, generative UI, shared state and human approvals; creator of the AG-UI protocol. | TypeScript | 38.2K | ~1.2M | Built in | Not stated | — |
| Rig Rust library for LLM applications with agents, tool calling, streaming and 20+ model providers, plus a terminal coding agent. | Rust | 9K | ~653K | Not stated | Not stated | — |
| Letta Open-source agent harness for stateful agents whose memory persists and improves with use, with a terminal UI, app server and TypeScript SDK. | TypeScript | 25.2K | ~174.5K | Not stated | Not stated | — |
| trueforge Open-source agent harness that runs the model loop for you, with MCP tools, skills, sandboxing, approvals and a chat UI. | TypeScript | 6.4K | — | Built in | Not stated | Yes |
| 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 | — |
| 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 | — |
| 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 |
| 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 | — |
| LangChainGo Go implementation of LangChain for writing LLM-based programs from composable building blocks. | Go | 9.7K | — | Not stated | Not stated | — |
| TEN Framework Open-source framework for real-time multimodal conversational AI, with RTC and WebSocket voice assistant examples. | Python | 11.2K | — | Not stated | Not stated | — |
| CAMEL Open-source Python framework for multi-agent systems: agent societies, memory, RAG, code interpreters, synthetic data and large-scale simulation. | Python | 18K | ~86.2K | Not stated | Not stated | Yes |
| Cloudflare Agents SDK TypeScript SDK for persistent AI agents on Cloudflare Durable Objects, with state sync, scheduling and MCP support. | TypeScript | 5.9K | — | Built in | Not stated | Yes |
| fast-agent CLI-first Python agent framework and coding agent with MCP, A2A and Agent Skills support, live streaming and human input. | Python | 3.9K | ~83.5K | Built in | Built in | Yes |
| attestix Python toolkit for signed identities, verifiable credentials and delegated authority for AI agents, with MCP and REST interfaces. | Python, JavaScript, Go, Java | 839 | ~690 | Built in | Not stated | — |
| lix Embeddable version control system for files and SQL tables, with branch, diff, merge and rollback across both. | JavaScript, Rust | 771 | ~2.4M | Not stated | Not stated | — |
| Stirrup Lightweight Python framework and starting template for agents that let the model choose its own approach to each task. | Python, TypeScript | 667 | ~279.7K | Built in | Not stated | — |
| agent-governance-toolkit Policy enforcement, identity, sandboxing and reliability tooling for autonomous AI agents, installable with one pip command. | Python, TypeScript, C# | 6.5K | ~121.3K | Not stated | Not stated | Yes |
| standards-sdk TypeScript SDK with reference implementations of Hashgraph Consensus Standards and a Registry Broker client. | TypeScript | 1.3K | ~171 | Not stated | Not stated | — |
| Patter Python and TypeScript SDK that gives an AI agent a phone number, with pluggable LLM, speech and telephony providers. | Python, TypeScript | 1.1K | ~167 | Not stated | Not stated | — |
| ART Open-source reinforcement learning framework that trains LLM agents on multi-step tasks using GRPO. | Python | 10.8K | ~10.9K | Not stated | Not stated | — |
| EvoAgentX Open-source framework that builds, evaluates and self-improves multi-agent LLM workflows from a goal. | Python | 3.4K | — | Not stated | Not stated | Yes |