A free course on making reliable AI coding agents has more than 22,000 GitHub stars to learn Harness Engineering teaches the installation around the model: instructions, tools, environment, memory and tests that keep an agent like Claude Code or Codex on track. It has 14 lectures and eight projects, in 15 languages, under the MIT license. High lighting from the latest updates: 1. Build a loop where one agent does the work and another checks it, instead of pushing by hand. 2. Grow the loop into a graph with parallel steps, a rolling path, and a human confirmation step. 3. Breakdowns of How Claude Code, Codex, DeepSeek and Pi build their harnesses. A ready-made skill that puts AgenTS.md, feature lists, and validation actions into your project. It builds on the OpenAI engineering posts on harnessed design. Name of the video: GitHub. @aipost 🏴.