# How Dex Horthy actually uses coding agents

HumanLayer CEO, 12-Factor Agents

**If you take one thing:** `/show-me`, diagrams, not walls of prose. his own skill makes agents explain plans and diffs as trees, call stacks and diagrams, so he can review them fast.

- **Agent:** HumanLayer (ide) ([source, 2026-08-01](https://x.com/dexhorthy/status/2083582284658245837))
- **Agent:** Codex ([source, 2026-08-01](https://x.com/dexhorthy/status/2083582284658245837))
- **Agent:** Claude Code ([source, 2026-09-23](https://x.com/dexhorthy/status/2102863697945469415))
- **Model:** GPT-5.6 Sol ([source, 2026-08-31](https://x.com/dexhorthy/status/2094228532184637911))
- **Model:** Claude Fable ([source, 2026-08-31](https://x.com/dexhorthy/status/2094228532184637911))
- **Review:** Still reads the code, one 1k-3k PR at a time ([source, 2026-08-01](https://x.com/dexhorthy/status/2083582284658245837))
- **Harness:** HumanLayer QRSPI: research and outline docs, Sol and Fable implement and review overnight, then split into small PRs ([source, 2026-08-25](https://x.com/dexhorthy/status/2092244659057909765))
- **Rules file:** ~/.claude/CLAUDE.md in his dotfiles (102 lines, Uncle Bob persona) ([source, 2025-12-27](https://github.com/dexhorthy/dotfiles/blob/12bc0cc708824c565c512f9914e58d376c237321/dotfiles/.claude/CLAUDE.md#L75))
- **Skills:** build-iterated-agentic-loop, design-control-loop, improve-claude-md, narrow-react-prop-types, rpi, show-me, visual-pr ([source, 2026-10-08](https://github.com/humanlayer/skills/tree/3b53bed02f89f5d5858b7dc68741b60ad64a2119/plugins))

## In their words

> Humanlayer (cc) QRSPI

> Took the codex pill, 5.5 for all coding

> For opus 5.5 in humanlayer - Just pick opus as model and if you have latest CC cli installed you’ll get 5.5 (ignore the context window warning)

> sol is very good at structural stuff. refactoring, or plumbing through a thick call stack without missing things, in general its just more thorough and technical.

> fable gives me more "look busy" vibes and it is much better at a handful of things like spatial reasoning and UI


Archetype (our label): Toolsmith. Newest source: 2026-10-08.
Card: https://www.prehistoriq.com/stacks/dexhorthy/ · Data: https://github.com/prehistoriq/stacks/blob/main/data/stacks/dexhorthy.json