Harness AI Agent Skills

Ultra-lightweight pure-Python alternative to Claude Code from HKU Data Intelligence Lab. ~98% of Claude Code's core tool capabilities in only 11,733 lines of code. Fully compatible with Anthropic Skills and the Claude Code plugin ecosystem. Supports any OpenAI-compatible model.

Terminal UI to manage AI coding-agent sessions (Claude Code, OpenCode, Codex, Grok, Gemini CLI) in tmux. Live status, group tree, quick prompts, diff review.

Cursor's coding-agent runtime built into the Cursor IDE. Reads .cursorrules, MCP servers, and Cursor commands. Available as CLI (cursor-agent) and inside the editor.

Google's coding-agent CLI running Gemini models. Terminal-based, supports MCP servers, and integrates with the Google Cloud agent stack.

Agent harness for complex codebases. Wraps Codex, OpenCode, and other coding-agent CLIs with token-efficient context management for long-running work.

Autonomous coding-agent harness that runs as a VS Code extension. Reads cline_rules, supports MCP, and executes multi-step tasks with human-in-the-loop approval.

Nous Research's open-source autonomous AI agent. Runs as a persistent daemon on your own infrastructure, connects to 16+ messaging platforms (Telegram, Discord, Slack, WhatsApp), and writes its own reusable skills from experience. Model-agnostic — Anthropic, OpenAI, Google, DeepSeek, Ollama.

Open-source visual workspace and harness for Claude Code and Codex. Browser-based UI over the terminal harness with session sharing and review tooling.

Open-source AI agent framework with a complete runtime, CLI, backend services, and web dashboard. Multi-model support (GPT-4o, Claude, Gemini, DeepSeek) with native Telegram/Discord/WhatsApp integration. Emerged as a Claude Code alternative after Anthropic paywalled third-party tool usage in April 2026.

Open-source coding-agent harness with model-agnostic backend. Terminal-first, supports Claude, GPT, and local models. MCP-native.

OpenAI's coding-agent CLI. Runs Codex models with tool use, shell execution, and file editing. Ships with the Responses API integration so context management happens inside the model call.

Mission Control for Claude Code. Native desktop app to browse, search, and drive Claude Code sessions with live status and diff review.

Multi-harness control plane for Claude Code, Codex, Cursor, and OpenCode. Quota-aware rotation across multiple subscriptions, shared thread state, and local-first execution.

OS-like agent runtime that sits between the model and your application. LobeHub's Chief Agent Operator hires agents from a 273K skill marketplace and runs them 24/7 in the cloud, reporting through Slack, Discord, and other platforms. Model as CPU, context window as RAM.

AI pair programming in your terminal. Model-agnostic harness that speaks to Claude, GPT, Gemini, and local models. Best-in-class git integration with auto-commits per edit.

Anthropic's official coding-agent CLI. Runs Claude in your terminal with tool use, file operations, and shell access. The reference harness that skills, sub-agents, hooks, and slash commands are built for.