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
- 0.853score
LlamaIndex
LlamaIndex
Open-source Python toolkit for RAG and agents over your own data, with event-driven workflows and 300+ integration packages.
HarnessAFreshness: A★ 52.6K↓ 1.4M/wk - 0.851score
Strands Agents
AWS
Open-source Python and TypeScript SDK for model-driven agents, with tools, MCP, multi-agent patterns and streaming.
HarnessAFreshness: A★ 8.9K↓ 8.9M/wk - 0.831score
CopilotKit
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.
HarnessAFreshness: A★ 38.2K↓ 286.2K/wk - 0.809score
Rig
Playgrounds
Rust library for LLM applications with agents, tool calling, streaming and 20+ model providers, plus a terminal coding agent.
HarnessAFreshness: A★ 9K↓ 152.4K/wk - 0.799score
Letta
Letta
Open-source agent harness for stateful agents whose memory persists and improves with use, with a terminal UI, app server and TypeScript SDK.
HarnessAFreshness: A★ 25.2K↓ 40.7K/wk - 0.787score
trueforge
truefoundry
Open-source agent harness that runs the model loop for you, with MCP tools, skills, sandboxing, approvals and a chat UI.
HarnessAFreshness: A★ 6.4K - 0.730score
Claude Agent SDK (Python)
Anthropic
Python SDK that runs the Claude Code agent loop inside your own program, with custom tools and hooks written as Python functions.
HarnessAFreshness: A★ 8.3K↓ 7.9M/wk - 0.714score
LangChain.js
LangChain
JavaScript and TypeScript framework of interoperable components for building LLM apps and agents, with LangGraph.js and Deep Agents above it.
HarnessAFreshness: A★ 18.3K - 0.713score
Claude Agent SDK (TypeScript)
Anthropic
TypeScript SDK that gives programs Claude Code's built-in tools for reading, editing and running code, installed from npm.
HarnessAFreshness: A★ 1.8K↓ 8.1M/wk - 0.705score
Eino
CloudWeGo (ByteDance)
Go framework for LLM applications with chat-model agents, multi-agent coordination, graph workflows and human-in-the-loop resume.
HarnessAFreshness: A★ 13.4K - 0.698score
PageIndex
VectifyAI
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.
HarnessAFreshness: A★ 39.6K↓ 43.6K/wk - 0.695score
LangChainGo
LangChainGo
Go implementation of LangChain for writing LLM-based programs from composable building blocks.
HarnessAFreshness: A★ 9.7K - 0.688score
TEN Framework
TEN Framework
Open-source framework for real-time multimodal conversational AI, with RTC and WebSocket voice assistant examples.
HarnessAFreshness: A★ 11.2K - 0.679score
CAMEL
CAMEL-AI
Open-source Python framework for multi-agent systems: agent societies, memory, RAG, code interpreters, synthetic data and large-scale simulation.
HarnessAFreshness: A★ 18K↓ 20.1K/wk - 0.673score
Cloudflare Agents SDK
Cloudflare
TypeScript SDK for persistent AI agents on Cloudflare Durable Objects, with state sync, scheduling and MCP support.
HarnessAFreshness: A★ 5.9K - 0.662score
fast-agent
evalstate
CLI-first Python agent framework and coding agent with MCP, A2A and Agent Skills support, live streaming and human input.
HarnessAFreshness: A★ 3.9K↓ 19.5K/wk - 0.662score
attestix
VibeTensor
Python toolkit for signed identities, verifiable credentials and delegated authority for AI agents, with MCP and REST interfaces.
HarnessAFreshness: A★ 839↓ 161/wk - 0.661score
lix
opral
Embeddable version control system for files and SQL tables, with branch, diff, merge and rollback across both.
HarnessAFreshness: A★ 771↓ 565.7K/wk - 0.657score
Stirrup
ArtificialAnalysis
Lightweight Python framework and starting template for agents that let the model choose its own approach to each task.
HarnessAFreshness: A★ 667↓ 65.3K/wk - 0.650score
agent-governance-toolkit
microsoft
Policy enforcement, identity, sandboxing and reliability tooling for autonomous AI agents, installable with one pip command.
HarnessAFreshness: A★ 6.5K↓ 28.3K/wk - 0.649score
standards-sdk
hashgraph-online
TypeScript SDK with reference implementations of Hashgraph Consensus Standards and a Registry Broker client.
HarnessAFreshness: A★ 1.3K↓ 40/wk - 0.646score
Patter
PatterAI
Python and TypeScript SDK that gives an AI agent a phone number, with pluggable LLM, speech and telephony providers.
HarnessAFreshness: A★ 1.1K↓ 39/wk - 0.643score
ART
OpenPipe
Open-source reinforcement learning framework that trains LLM agents on multi-step tasks using GRPO.
HarnessAFreshness: A★ 10.8K↓ 2.5K/wk - 0.641score
EvoAgentX
ANative-Lab
Open-source framework that builds, evaluates and self-improves multi-agent LLM workflows from a goal.
HarnessAFreshness: A★ 3.4K