---
title: "You Can Learn AI Agent Harness In Real Code In 20 Min | Loop Engineering, Memory, Eval, Open Source"
source_url: https://youtu.be/rvRyBhILrls
captured_at: 2026-07-15
author: "Sean‘s AI Stories"
contributor: "ชิดชนก"
platform: youtube
---
# You Can Learn AI Agent Harness In Real Code In 20 Min | Loop Engineering, Memory, Eval, Open Source

youtube video by **Sean‘s AI Stories**, 20m49s, uploaded 2026-07-14. URL: https://youtu.be/rvRyBhILrls

## Shared in LINE Note+
- 2026-07-15 11:21 by ชิดชนก

## Description
Try  Me  Open Source:  I open sourced Waku Agent, a local-first personal AI assistant, and in this video I walk through the real code behind everything from my last three videos: the harness, the agent loop, all three memory pillars, tracing, and eval. It scheduled the World Cup quarter final on my calendar, remembered who my friends are, answered me over Telegram, and even responded to a voice wake word. Nothing runs in the cloud. The whole agent lives on your laptop, and you own it. Step by step, and if the code feels heavy, the theory videos below will catch you up.

Previous episodes:
AI Agent Harness & Loop Engineering: [
AI Agent Memory System: [
AI Agent System Design: [
Hermes Agent Harness: [

For those who are not familiar with these terms: it's all buzzwords. What I demo in this video is exactly what these words mean.

Chapters:
0:00 What is Waku Agent (local-first, open source)
0:35 Demo: World Cup games straight to my calendar
2:11 Test: memory retrieval, "who is Sergey"
3:13 Trace: tokens, cost, latency
3:50 Telegram gateway with BotFather
4:35 Test: saving a new memory from chat
5:32 Reading the code: clone + quick start
6:44 SOUL.MD: the agent's system prompt, edite