Awesome Harness Engineering

The open source coding agent.

Model Context Protocol Servers

🙌 OpenHands: AI-Driven Development

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

Universal memory layer for AI Agents

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

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.

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

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.

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.

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

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).

Hindsight: Agent Memory That Learns

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

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

The best agent harness.

Secure, Fast, and Extensible Sandbox runtime for AI agents.

Multi-Agent Harness for Production AI

AI Observability & Evaluation

Visual testing tool for MCP servers

Instant, Concurrent, Secure & Lightweight Sandbox for AI Agents.

Orchestrate sandboxed coding agents in TypeScript with sandcastle.run()

Build an agent harness and control it end-to-end. Open-source SDK for production AI agents in Python & TypeScript - any model, any cloud.

TypeScript AI agent orchestration framework with dynamic workflows. Describe the goal, not the graph: a coordinator plans the task DAG at runtime and runs it on any LLM (Claude, ChatGPT, Gemini, DeepSeek, or local models).

Omnigent is an open-source AI agent framework and meta-harness: orchestrate Claude Code, Codex, Cursor, Pi, and custom agents — swap harnesses without rewriting, enforce policies and sandboxing, and collaborate in real time from any device.

🧊 Open source LLM observability platform. One line of code to monitor, evaluate, and experiment. YC W23 🍓

Self-hosted control plane for AI agents: dispatch tasks, review runs, track spend, and operate OpenClaw, Claude Code, Codex, and other runtimes.

All-in-One Sandbox for AI Agents that combines Browser, Shell, File, MCP and VSCode Server in a single Docker container.

Zep | Examples, Integrations, & More

Next Generation Agentic Proxy for AI Agents and MCP servers

The missing DevTools for Claude Code — inspect session logs, tool calls, token usage, subagents, and context window in a visual UI. Free, open source.

The World's First Unified Virtual Filesystem For AI Agents

Amazon Bedrock Agentcore accelerates AI agents into production with the scale, reliability, and security, critical to real-world deployment.

Squad: AI agent teams for any project

Skills, MCP servers, Custom Agents, Agents.md for SDKs to ground Coding Agents

Open-source, end-to-end platform for evaluating, observing, and improving LLM and AI agent applications. Tracing · Evals · Simulations · Datasets · Gateway · Guardrails. Self-hostable. Apache 2.0.

Coding Agent singularly focused efficiency and context curation. Reduces API costs by 50-80% vs other agent AND improves the code quality at the same time. Uses Hash Anchored edits, massively parallel operations, AST manipulation and many many other optimizations. https://dirac.run/

a recursive self-improving harness designed to help your agents (and future iterations of those agents) succeed on any task

Open-source AI agent harness in native Rust — GUI, CLI, headless, and webapp from one binary. Multi-provider, MCP, skills, plugins, agent teams.

A production-ready runtime framework for agent apps with secure tool sandboxing, Agent-as-a-Service APIs, scalable deployment, full-stack observability, and broad framework compatibility.

Audit-grade multi-agent orchestration for CLI coding agents (Claude Code, Codex, Gemini CLI, +40 more). HMAC-chained audit log, signed agent cards, per-artefact lineage, air-gap deploy. The orchestrator your compliance team will sign off on. https://bernstein.run

State machine guardrails for AI agents

React components for visualizing traces from AI agents

MCP Fusion - The TypeScript framework for secure MCP servers.

Human-in-the-Loop Protocol for Autonomous Agent Services — Open Standard (v0.8)