Learn Claude Code
shareAI-lab/learn-claude-code
Bash is all you need — a nano agent harness built from 0 to 1.
A nano, Claude Code–like agent harness built from scratch in the open as a teaching artifact — every piece of the loop, tools and context handling implemented step by step so you can read a complete harness in an afternoon.
In the news
DeepSeek ships Harness Desktop; the 'everything is a plugin' harness passes 240k stars
DeepSeek releases a macOS and Windows Desktop app for DeepSeek Harness, its open-source agent harness where everything — tools, sub-agents, even the loop — is a plugin. The repo passed 240k stars within three months of its August launch, making it the fastest-growing harness in the field's history.
HarnessTax: harness choice swings agent cost more than model choice
Arena.ai's HarnessTax study tests 21 model–harness combinations across Claude Code, Codex CLI and Pi, finding harness choice can significantly change cost even at similar task success rates. Weeks earlier, SWE-bench Pro analysis showed swapping harnesses moved pass@1 more than model upgrades (23%→52% on GLM-5.2) — and that harness rankings barely transfer across models.
Related projects
superpowers
obra/superpowers
An agentic skills framework and software methodology that works.
superpowers is the most-adopted skills pack in harness engineering: skills, instincts, memory, security and research-first workflows for Claude Code and 13 other harnesses (Codex, Cursor, opencode, Gemini CLI and more). Treats harness engineering itself as the discipline.
DeepSeek Harness
deepseek-ai/deepseek-harness
Everything is a Plugin — DeepSeek's open agent harness.
DeepSeek Harness is the breakout open-source harness of 2026: an architecture where everything — tools, subagents, even the loop itself — is a plugin. A Desktop app for macOS and Windows followed in October 2026, and the project passed 240k stars in under three months.
opencode
anomalyco/opencode
The open source coding agent — terminal-first, model-agnostic.
opencode is a blazingly popular terminal coding agent: a language-server-backed TUI that works with any provider, scriptable and hackable. Its growth made it the open counterweight to Claude Code.