Durable Agent Harness

Public engineering notebook by Alex Lennon (@embedded_iot) under the Chop Wood Carry Water brand — building a durable working relationship with AI coding agents.

🌐 Site: https://chopwoodcarrywater.uk/
📦 Repo: https://github.com/DynamicDevices/durable-agent-harness
🏷️ Baseline: v1.2 (2026-09-12) in BASELINE-v1.2.md · previous v1.1 🤖 Agents: AGENTS.md · https://chopwoodcarrywater.uk/agents.html

First-person voice, short blog, playbook, patterns, and honest measurement — personal brand, not a company brochure.

Here, the working relationship is the human experience and the durable agent harness is the versioned, tested mechanism that makes it repeatable. Portable skills are its core; product-specific guidance and controls are host adapters; Codex and Cursor are the cockpits in which it runs.

Layer	Meaning in this notebook
Working relationship	The human experience: purpose, judgement, collaboration and learning
Durable harness	Skills, policy, memory, tools, gates, tests and feedback that should survive a host change
Host adapter	Codex- or Cursor-specific guidance, hooks, permissions and task integration
Cockpit / host	Codex or Cursor: the agent runtime and interface supplying native controls

Topics: ai · agents · cursor · developer-tools · llm · engineering · documentation · productivity

Site SEO includes canonical URLs, per-insight Open Graph / Twitter cards, BlogPosting JSON-LD, RSS, robots.txt, llms.txt, and a real-URL sitemap. Contract: docs/NOTES-SOCIAL-SHARING.md.

What’s inside

Area	What you get
60 minutes	Timed checklist + Codex starter pack (Cursor pack retained)
Codex migration	Portable Agent Skills, AGENTS.md, worktrees/handoff, host-native controls, self-evals
Playbook	Twelve steps to build a thin harness from scratch
Learning	MemPalace memory + Kaizen → Hansei → Toyota Way Practices
Runtime	Preloop (policy/audit under P0) + OpenRouter (multi-model routing) + PR commit checks (preloop status)
Channels & lean	WhatsApp/Briar triage, media ingest, token-lean skills, desktop MCQ, voice, CI checks
Starter kit	Copy-paste templates for skills, rules, patterns, lanes, clocks, capability maps (starters/)
Explore	Timeline, stack, capability map, patterns, glossary/FAQ, research
Cases	Before/after outcomes that show the harness at work
Measure	Tenure clocks, metrics that aren’t fake multipliers, weekly ritual
Insights	What broke / locked / earned a place on disk — sparks in blog-inbox.md, published at EOW
About	Notebook blurb; contributor notes in PRIVACY.md

Local check

npm install
npx playwright install chromium
npm run cards     # regenerate 1200×627 insight cards (Pillow)
npm test          # sync + privacy gate + Playwright (desktop + mobile)
npm run serve     # http://127.0.0.1:4173

Start a private insight package from a rough thought or UTF-8 transcript:

npm run insight:new -- --title "The working title" --text "The first thought"
npm run insight:new -- --title "The working title" --input ~/Downloads/transcript.txt

Drafts default to a private directory outside this public repository and are not published automatically. Use --output-root to select another private location. After publishing the associated LinkedIn post, add its HTTPS URL as discussionUrl so the article invites readers to join that conversation.

Create or refresh a public-but-unlisted review page from a private package:

npm run insight:review -- --package /path/to/private-package
npm run insight:review -- --package /path/to/private-package --replace
npm run sync

The review URL is /review/the-working-title.html. Only the CWCW insight draft section and publication metadata are copied into this public repository; research notes, raw material and social copy stay in the private package. Review pages are visibly marked as drafts, carry noindex,nofollow, and are excluded from Insights, RSS, the sitemap, llms.txt and social-card generation. They are unlisted, not confidential: anyone with the URL or repository access can read them. Every review requires a newly generated, post-specific 1200×627 editorial image derived from that draft's image brief; reusable generic cards are not an acceptable substitute. The generated-image disclosure, meaningful alt text and the exact ../assets/review/<slug>.png path must be present in the manifest before insight:review will promote it. Publishing remains a separate, deliberate edit to content/blog.json.

content/blog.json is the insight source of truth. npm run sync renders static docs/notes/*.html, feed.xml, sitemap.xml and llms.txt; GitHub Pages serves docs/ from main. Review the PR and local Lighthouse results before merging. After production publish, run new URLs through LinkedIn Post Inspector.

Four clocks (frozen starts)

Clock	Start
Serious hands-on AI	2025-06-06
Cursor as cockpit	2025-07-23
Codex as cockpit	2026-08-30
Versioned harness	2026-05-31

Licence

• Notebook content: CC BY-SA 4.0
• Site code / scripts / tests: MIT

See LICENSE for the split.

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AI-assisted (Codex) under Alex’s direction. Use at your own risk.