Saturday, April 25, 2026 issue 044 evening edition
Issue 044
Tech
Technical notes from mager.co: agents, CLIs, personal software, and the small systems I keep coming back to.
Lead story
DESIGN.md: Reverse Design Engineering for Portable Taste
I reverse engineered several of my own sites into DESIGN.md files to see how much of a design system can actually be described, and why writing down design intent might be more reusable than it looks.
Latest
Issue notes
Newest first, with the lead story pulled above the fold. Each published tech post advances the issue number.
sorted newest first 2018 to 2026
- 2026-04-20 Claude Code: 10 CLI flags you probably aren't using A practical tour of Claude Code flags that are easy to miss but genuinely useful once you move past the default interactive loop.
- 2026-04-11 OpenClaw: I Switched My Agent Stack from Claude to OpenAI Codex Anthropic shutting down OAuth-based Claude Code access forced my hand. Here's how I moved OpenClaw to OpenAI Codex, why Codex makes more sense inside a real agent harness than it did on its own, and why brainpack changes the switching cost.
- 2026-03-28 gstack: Garry Tan's Claude Setup Is 🔥 The Y Combinator CEO open-sourced his entire Claude Code workflow. Here are the 10 skills worth knowing — including why office-hours should be the first thing you run on any new idea.
- 2026-03-27 Anthropic's Knowledge Work Plugins: The 10 Essential Tools for Modern Tech Teams I tested Anthropic's official Claude plugins for knowledge workers. Here are the 10 that deliver the most value for PMs, engineers, sales teams, and operators.
- 2026-03-26 Loooom: I Built a Skill to Teach Claude to Hear Music I used Gemini to write a Loooom skill, installed it in Claude Code, and got a full audio analysis report on a 37-second piano recording of Espresso. Turns out AIs teaching AIs new senses is a surprisingly powerful pattern.
- 2026-03-25 beatbrain: 3 Seconds to 200ms I rebuilt the beatbrain backend in an afternoon. Parallel fetching, Firestore caching, and a podcast discovery engine that indexes 100+ categories. Here's the whole story.
- 2026-03-21 Kotsu: The Knack of Japanese I built a Japanese learning site in a morning because I wanted something I could pull up on my phone and just look at characters. Here's how Gemini wrote the prompt and magerbot built the whole thing.
- 2026-03-21 DM your agent with Claude Code Channels Claude Code's new channels feature lets you push messages from Telegram and Discord into a running session. Here's how it works, why mobile access changes everything, and how I'd wire it into my projects.
- 2026-03-20 autoresearch on Loooom: Teaching a Skill to Improve Itself Dogfooding Karpathy's autoresearch pattern on my own skill marketplace. How I'm using evals and tight feedback loops to make the learn-anything skill measurably better.
- 2026-03-19 Software Factory: The End Goal of Agentic Engineering Everyone's talking about building a software factory. Here's where the term came from and how engineers can start thinking about building one.
- 2026-03-18 prxps: I Let AI Analyze Every First-Round March Madness Matchup 12 hours before my bracket was due, I used Gemma-3-27b to generate unique insights for all 32 first-round games. Here's what the AI found — and what it got wrong.
- 2026-03-17 Open SWE: Build Your Own Internal Coding Agent in 10 Minutes LangChain just dropped Open SWE — an open-source framework for building internal coding agents like Stripe's Minions, Ramp's Inspect, and Coinbase's Cloudbot. Here's what it is, how it works, and how to customize it.
- 2026-03-14 autoresearch: Karpathy's Blueprint for Agents That Improve Themselves Andrej Karpathy open-sourced a loop where AI agents run experiments, measure results, and keep what works — all while you sleep. Here's how the pattern works and how I'm applying it beyond LLM training.
- 2026-03-14 Claude Agent SDK: Build Your Own AI Terminal in 10 Minutes The Claude Agent SDK gives you the same engine that powers Claude Code, fully programmable. Here's how to build a custom TUI with it in 10 minutes.
- 2026-03-14 Loooom MCP: Let Any AI Discover and Install Skills Mid-Conversation I built an MCP server for Loooom so AI agents can search, explore, and install Claude Code skills without ever leaving their context.
- 2026-03-14 OpenClaw: I Turned Three Shell Aliases Into a Real CLI Command How a weekend contribution to OpenClaw replaced my autossh aliases with `openclaw tunnel up/down/status` — and what I learned reading a real codebase to do it right.
- 2026-03-14 OpenViking: The Open-Source Context Database Your Agents Have Been Waiting For Stop stuffing your prompts. OpenViking gives AI agents a filesystem-native brain — tiered, retrievable, self-evolving context at 91% lower token cost.
- 2026-03-13 Isaac Asimov's Three Laws: From Science Fiction to AI Alignment Crisis Eighty years after Asimov's Three Laws of Robotics debuted, we're building the future he imagined—without the safeguards. What the 'Father of Robotics' got right, where his vision fails, and why 2026's AI alignment problem is harder than fiction.
- 2026-03-13 blog-seo: Audit Any Blog's SEO With a Claude Code Skill I kept fixing the same SEO issues by hand — missing keywords, empty hero images, weak descriptions. So I built a Claude Code skill that audits any blog's frontmatter and runs quality evals.
- 2026-03-12 LangGraph: Build Stateful Multi-Agent Systems That Don't Crash LangGraph is the production framework for complex agent workflows. Here's how to build a real-time chat system with persistent state, human-in-the-loop, and multi-agent orchestration.
- 2026-03-10 DeepAgents: The Claude Code Alternative That Works With Any LLM LangChain just shipped DeepAgents — a batteries-included agent harness that brings Claude Code's magic to any model. Here's your 10-minute deep dive.
- 2026-03-08 Claude Code: How to Write, Eval, and Iterate on a Skill Part 2 of the prompt verification series. We covered output quality testing with promptfoo — now we tackle the harder problem: does your skill even fire?
- 2026-03-08 Loooom: I Built It for the Bots Most websites beg search engines for attention. I flipped it — Loooom is machine-first, humans secondary. Here's what that actually means in practice.
- 2026-03-07 LangGraph + Claude Agent SDK: The Ultimate Guide to Multi-Agent Systems in 2026 A deep dive into the two most powerful tools for building production-grade multi-agent systems — LangGraph's graph-based orchestration and Anthropic's Claude Agent SDK (formerly Claude Code SDK).
- 2026-03-07 ME.md: robots.txt for human consciousness Stop re-prompting every AI session. One file. Every AI knows you — and your agents. Introducing ME.md on Loooom.
- 2026-03-06 Build Your Own Agent Team with ACP I run two AI agents — magerbot handles code and ops, genny runs my life. Inspired by the Agent Communication Protocol, here's how I got them to actually talk to each other. Now with a full TUI built on the Claude Agent SDK.
- 2026-03-04 OpenClaw: Meet Genny, My AI Life Architect I built a second AI agent to manage the parts of my life that code can't fix — exercise, nutrition, travel, and living to 100.
- 2026-02-26 promptfoo: The Ultimate Guide to Unit Testing Your AI Prompts Stop shipping AI features blind. Here's everything you need to know about unit testing prompts — from five-minute quick starts to CI/CD pipelines, agent workflow testing, and building a regression suite that actually catches breakage.
- 2026-02-23 promptfoo: Rate Your Claude Code Skills Before Your Users Do Spec compliance tells you if a skill is readable. Evals tell you if it's actually good. Here's how we added a public quality score to every Loooom plugin.
- 2026-02-23 My AI Has a Brain Now The problem: Every session, my AI wakes up fresh. The worse problem: Even when AI tools do remember, they trap it in proprietary black boxes. So I built a brain that follows me across tools.
- 2026-02-22 Loooom: A Claude Code Plugin Marketplace on GitHub I built Loooom — a Claude Code plugin marketplace where GitHub is the database. Add it with one command and install skills from Franklin, Plato, Lincoln, and more. No signup. Works today.
- 2026-02-22 OpenClaw + Tailscale: Your Always-On AI Agent, Accessible from Anywhere How to run OpenClaw on a Mac Mini 24/7, lock it down with Tailscale, and load your agent's brain with brainpack — so your laptop can reach it from anywhere on your tailnet.
- 2026-02-21 brainpack: Move Your AI Agent's Entire Brain to a New Computer in 60 Seconds Your AI agent has memories, skills, and a personality. Here's how to pack it all up and ship it to a new machine — whether you're the human or the agent reading this.
- 2026-02-16 Building a Music Agent CLI with pi-mono How I used the pi-mono toolkit — the same engine behind OpenClaw — to build a free, terminal-based music friend that reads the beatbrain discover feed and recommends what to listen to.
- 2026-02-10 Entire CLI: Version Control for Your Agent Sessions A quick look at Entire, a CLI tool that captures AI agent sessions alongside your git commits. Think flight recorder for AI-assisted development.
- 2026-02-08 I Turned My Design Taste Into a Claude Code Skill I analyzed three of my projects, interviewed myself about what makes a UI hot, and packaged it all into a reusable skill for Claude Code.
- 2026-02-03 Moving Beyond the Prompt: How OpenClaw Actually Does the Work A practical guide to building a multi-agent AI system with OpenClaw. One principal agent, multiple specialists, shared skills, and the workspace files that give them personality. Includes real examples from my blog, sports app, and music discovery projects.
- 2025-12-25 Building an AI Sports Betting Recommendation Engine with Gemma A practical guide to building two-stage AI recommendations: use embeddings for fast retrieval, then small LLMs like Gemma 3 for natural language explanations. The real skill? Curating context, not writing algorithms.
- 2025-11-29 beatbrain: A Social Music Discovery App beatbrain is a social music discovery app built on Go Fx and Firestore. Find hot new releases, share your favorites, and see what your friends are actually listening to — Spotify meets Last.fm, built from scratch.
- 2022-12-30 Learning 25 programming languages in 25 days with Advent of Code Instead of just using a single language, I wanted to solve the puzzle in a language I know, then lurk the internet for the solution in another language each day.
- 2021-01-03 Building a coffee API with Go Fx and Firestore How I used Go Fx dependency injection and Firestore to build an open coffee bean database and REST API from scratch — full walkthrough from blank main.go to deployed app.
- 2020-02-22 Hello World mager.co is back after years away. Here's what I'm building, what I'm obsessing over, and why this time it sticks.
- 2018-02-01 How I built a decentralized Ethereum app for the Super Bowl My explorations into decentralized apps and blockchain.