Awesome Harness Engineering

The LLM Evaluation Framework

Browser Harness | Self-healing harness that enables LLMs to complete any task.

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

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

Structured Outputs

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

SkillOpt is a text-space optimizer that trains reusable natural-language skills for frozen LLM agents through trajectory-driven edits, validation-gated updates, and deployable best_skill.md artifacts.

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

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

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

Open-source & free — Battle-tested at Alibaba's scale. Hybrid architecture code review tool: deterministic pipelines + LLM Agent, precise line-level comments, built-in fine-tuned ruleset (NPE, thread-safety, XSS, SQL injection), OpenAI & Anthropic compatible.

Build effective agents using Model Context Protocol and simple workflow patterns

A meta-skill that designs domain-specific agent teams, defines specialized agents, and generates the skills they use.

OpenShell is the safe, private runtime for autonomous AI agents.

Open-source observability for your GenAI or LLM application, based on OpenTelemetry

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

NeMo Guardrails is an open-source toolkit for easily adding programmable guardrails to LLM-based conversational systems.

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).

[EMNLP'23, ACL'24] To speed up LLMs' inference and enhance LLM's perceive of key information, compress the prompt and KV-Cache, which achieves up to 20x compression with minimal performance loss.

The first "code-first" agent framework for seamlessly planning and executing data analytics tasks.

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.

Python SDK for AI agent monitoring, LLM cost tracking, benchmarking, and more. Integrates with most LLMs and agent frameworks including CrewAI, Agno, OpenAI Agents SDK, Langchain, Autogen, AG2, and CamelAI

Fast and Accurate Code Search for Agents. Uses ~98% fewer tokens than grep+read

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

Deepsec is a security harness for finding vulnerabilities in your codebase powered by coding agents

Persistent memory system for AI coding agents. Agent-agnostic Go binary with SQLite + FTS5, MCP server, HTTP API, CLI, and TUI.

AI Agent Governance Toolkit — Policy enforcement, zero-trust identity, execution sandboxing, and reliability engineering for autonomous AI agents. Covers 10/10 OWASP Agentic Top 10.

Zep | Examples, Integrations, & More

autonomous harness engineering

TencentDB Agent Memory delivers fully local long-term memory for AI Agents via a 4-tier progressive pipeline, with zero external API dependencies.

AI observability platform for production LLM and agent systems.

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.

A Comprehensive Benchmark to Evaluate LLMs as Agents (ICLR'24)

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.

agent-sandbox enables easy management of isolated, stateful, singleton workloads, ideal for use cases like AI agent runtimes.

Agent harness to make your slop code well-engineered and beautiful.

Squad: AI agent teams for any project

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