What is an Agent Harness? and How to build a great one!
To apply 40% off 3 months of Coursera plus - https://imp.i384100.net/c/7245724/3880401/14726 Google AI Essentials - https://imp.i384100.net/1GW56D Prompt Engineering for ChatGPT - https://imp.i384100.net/gRWb9g Gen AI with LLMs - https://imp.i384100.net/n421aV IBM AI Developer - https://imp.i384100.net/R06yzX In this video, I define what an agent harness is (and what it isn’t), explain how it differs from frameworks like LangChain, LangGraph, AutoGen, and CrewAI, and show how a harness turns a one-shot model into an agent that can act, observe results, and iterate toward a solution. I break down nine key harness components: the while-loop engine, context management and compaction, tools vs. skills with a registry, subagent management, built-in skills, session persistence/memory, dynamic system prompt assembly from files like CLAUDE.md or AGENTS.md, lifecycle hooks (pre/post tool), and permissions/safety with dynamic command classification and user approvals. I then walk through a minimal Python reference implementation covering these pieces, including tool descriptors, subagent archetypes, append-only JSON event logs, and prompt assembly considerations like prefix caching. My voice to text App: whryte.com Website: https://engineerprompt.ai/ RAG Beyond Basics Course: https://prompt-s-site.thinkific.com/courses/rag Signup for Newsletter, localgpt: https://tally.so/r/3y9bb0 Let's Connect: 🦾 Discord: https://discord.com/invite/t4eYQRUcXB ☕ Buy me a Coffee: https://ko-fi.com/promptengineering |🔴 Patreon: https://www.patreon.com/PromptEngineering 💼Consulting: https://calendly.com/engineerprompt/consulting-call 📧 Business Contact: engineerprompt@gmail.com Become Member: http://tinyurl.com/y5h28s6h 💻 Pre-configured localGPT VM: https://bit.ly/localGPT (use Code: PromptEngineering for 50% off). Signup for Newsletter, localgpt: https://tally.so/r/3y9bb0 00:00 What Is a Harness 01:50 Harness vs Frameworks 03:19 Nine Core Components 03:49 Loop and Context Control 05:41 Tools Skills and Subagents 06:57 Sponsor - Coursera 09:03 Memory Prompts and Hooks 11:41 Permissions and Safety Layer 13:04 Build a Mini Harness 13:18 Reference Implementation Walkthrough
