AI Agent Harnesses

April 4, 2026 · View on GitHub

Point-in-time snapshot: April 2026

A curated list of projects describing themselves as AI agent harnesses or related to "harness engineering."

A Note On Terminology

The term "agent harness" emerged in late 2025 / early 2026 as a way to describe the orchestration layer that runs an AI agent. A harness manages the tool-dispatch loop, permissions, context, and lifecycle of an agent — as distinct from a framework (which provides higher-level abstractions for building agents) or a backend (which provides the inference and model serving).

The term gained traction partly through the adjacent concept of "harness engineering" — the practice of configuring and optimizing these orchestration layers (writing CLAUDE.md files, designing tool schemas, structuring agent prompts, etc.).

This list captures projects that self-identify with the "harness" label as of April 2026. The terminology is still fluid and not universally agreed upon — some projects listed here blur the line between harness, framework, and agent platform.


Agent Harnesses

Projects that provide runtime orchestration for AI agents — tool dispatch, conversation loops, context management, and agent lifecycle.

ProjectDescriptionLanguageStars
bytedance/deer-flowOpen-source long-horizon SuperAgent harness that researches, codes, and creates. Handles tasks from minutes to hours using sandboxes, memories, tools, subagents.Python57,759
code-yeongyu/oh-my-openagentAgent harness (previously oh-my-opencode) with multi-provider support.TypeScript48,154
langchain-ai/deepagentsAgent harness built with LangChain and LangGraph. Planning tool, filesystem backend, and subagent spawning.Python19,118
aden-hive/hiveOutcome-driven agent development framework and runtime harness. Self-improving, human-in-the-loop.Python10,038
xerrors/YuxiAgent harness integrating LightRAG knowledge base and knowledge graphs. Built with LangChain + Vue + FastAPI, supports MCP.Python4,805
mindfold-ai/TrellisAgent harness for agentic coding workflows.Python4,610
HKUDS/OpenHarnessOpen Agent Harness.Python3,363
can1357/oh-my-piAI coding agent for the terminal — hash-anchored edits, optimized tool harness, LSP, subagents.TypeScript2,646
kevinrgu/autoagentAutonomous harness engineering.Python2,084
chrysb/alphaclawSetup harness for OpenClaw. Deploy in minutes, stay running for months.JavaScript943
e10nMa2k/cc-miniUltra-light harness scaffolding for AI agents, a mini version of Claude Code.Python677
truffle-ai/dextoCoding agent and general agent harness for building and orchestrating agentic applications.TypeScript608
Chachamaru127/claude-code-harnessClaude Code dedicated development harness — autonomous Plan-Work-Review cycle.Shell420
aristoteleo/PantheonOSEvolvable, distributed agent framework and harness for data science and bioinformatics.Python370
MaxGfeller/open-harnessCode-first, composable SDK to build powerful AI agents.TypeScript337
vortezwohl/AutonoReAct-based highly robust autonomous agent (harness) framework. MCP support.Python209
aiming-lab/AutoHarnessAutomated harness engineering for AI agents — audit, governance, safety.Python181
dust-tt/srchdResearch agents harness.TypeScript69
thu-nmrc/OpenHarnessFully autonomous AI agent execution framework for OpenClaw built on harness engineering. From Tsinghua University.Python62
thu-nmrc/OpenHarness-For-CodexSpecialized variant of OpenHarness designed for AI-driven software development.Python39
mastersof-ai/harnessAgent runtime with full system prompt control. Define agents in markdown, run in terminal TUI or web UI. Powered by Claude Agent SDK.TypeScript31

Resource Lists & Guides

Projects focused on curating resources, guides, and best practices for harness engineering rather than providing a harness runtime.

ProjectDescriptionLanguageStars
walkinglabs/awesome-harness-engineeringAwesome tools and guides for harness engineering.1,264
AutoJunjie/awesome-agent-harnessCurated list of agent harness projects, orchestration tools, and developer resources.277
Picrew/awesome-agent-harnessAwesome list of agent harness engineering resources — projects, tools, benchmarks, and guides.Python109
alchemiststudiosDOTai/harness-engineeringHarness engineering discussion — shortcuts, automation, hacks, and productivity with code agents.Shell87
jrenaldi79/harness-engineeringContext engineering for coding agents — CLAUDE.md templates, enforcement, and best practices field guide.JavaScript55

Star counts as of April 2026. This is a static snapshot and will not be updated.