Awesome Harness Engineering

An agentic skills framework & software development methodology that works.

The agent harness performance optimization system. Skills, instincts, memory, security, and research-first development for Claude Code, Codex, Opencode, Cursor and beyond.

The open source coding agent.

Production-ready platform for agentic workflow development.

Model Context Protocol Servers

🙌 OpenHands: AI-Driven Development

An open-source long-horizon SuperAgent harness that researches, codes, and creates. With the help of sandboxes, memories, tools, skill, subagents and message gateway, it handles different levels of tasks that could take minutes to hours.

AI agent toolkit: unified LLM API, agent loop, TUI, coding agent CLI

Bash is all you need - A nano claude code–like 「agent harness」, built from 0 to 1

Universal memory layer for AI Agents

The best-benchmarked open-source AI memory system. And it's free.

Python SDK, Proxy Server (AI Gateway) to call 100+ LLM APIs in OpenAI (or native) format, with cost tracking, guardrails, loadbalancing and logging. [Bedrock, Azure, OpenAI, VertexAI, Cohere, Anthropic, Sagemaker, HuggingFace, VLLM, NVIDIA NIM]

an open source, extensible AI agent that goes beyond code suggestions - install, execute, edit, and test with any LLM

A collection of notebooks/recipes showcasing some fun and effective ways of using Claude.

Chrome DevTools for coding agents

"CLI-Anything: Making ALL Software Agent-Native" -- CLI-Hub: https://clianything.cc/

Installable GitHub library of 1,800+ agentic skills for Claude Code, Cursor, Codex CLI, Gemini CLI, Antigravity, and more. Includes specialized plugins, installer CLI, bundles, workflows, and official/community skill collections.

Build resilient agents.

Playwright MCP server

Compress tool outputs, logs, files, and RAG chunks before they reach the LLM. 60-95% fewer tokens, same answers. Library, proxy, MCP server.

🪢 Open source AI engineering platform: LLM evals, observability, metrics, prompt management, playground, datasets. Integrates with OpenTelemetry, LangChain, OpenAI SDK, LiteLLM, and more. 🍊YC W23

High-performance code intelligence MCP server. Indexes codebases into a persistent knowledge graph — average repo in milliseconds. 158 languages, sub-ms queries, 99% fewer tokens. Single static binary, zero dependencies.

Composio powers 1000+ toolkits, tool search, context management, authentication, and a sandboxed workbench to help you build AI agents that turn intent into action.

Cognee is the open-source AI memory platform for agents. Give your AI agents persistent long-term memory across sessions with a self-hosted knowledge graph engine.

Self-evolving Context Database for AI Agents. Unify Agent Memory, Knowledge RAG and Skills.

DeepSeek-native AI coding agent for your terminal. Engineered around prefix-cache stability — leave it running.

Mastra is the modern TypeScript framework for AI-powered applications and agents.

The batteries-included agent harness.

A format specification for describing a visual identity to coding agents. DESIGN.md gives agents a persistent, structured understanding of a design system.

The AI Toolkit for TypeScript. From the creators of Next.js, the AI SDK is a free open-source library for building AI-powered applications and agents

#1 Persistent memory for AI coding agents based on real-world benchmarks

Platform for stateful agents: AI with advanced memory that can learn and self-improve over time.

Test your prompts, agents, and RAGs. Red teaming/pentesting/vulnerability scanning for AI. Compare performance of GPT, Claude, Gemini, DeepSeek, and more. Simple declarative configs with command line and CI/CD integration. Used by OpenAI and Anthropic.

Debug, evaluate, and monitor your LLM applications, RAG systems, and agentic workflows with comprehensive tracing, automated evaluations, and production-ready dashboards.

Open-source infrastructure for Computer-Use Agents. Sandboxes, SDKs, and benchmarks to train and evaluate AI agents that can control full desktops (macOS, Linux, Windows).

Context window optimization for AI coding agents. Sandboxes tool output (98% reduction), persists session memory, and enforces routing across 17 platforms via MCP + hooks.

Hindsight: Agent Memory That Learns

A collection of projects designed to help developers quickly get started with building deployable applications using the Claude API

The LLM Evaluation Framework

"OpenHarness: Open Agent Harness with a Built-in Personal Agent--Ohmo!"

AG-UI: the Agent-User Interaction Protocol. Bring Agents into Frontend Applications.

Fully autonomous & self-evolving research from idea to paper. Chat an Idea. Get a Paper. 🦞

Open Source framework for voice and multimodal conversational AI

Open-source, secure environment with real-world tools for enterprise-grade agents.

The best agent harness.

IronClaw is an Agent OS focused on privacy, security and extensibility

Never stop coding. Free AI gateway: one endpoint, 231+ providers (50+ free), connect Claude Code, Codex, Cursor, Cline & Copilot to FREE Claude/GPT/Gemini. RTK+Caveman stacked compression saves 15-95% tokens, smart auto-fallback, MCP/A2A, multimodal APIs, Desktop/PWA.

Multi-Agent Harness for Production AI

AI Observability & Evaluation

Visual testing tool for MCP servers