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LifeOS Development Skill

Builds, tests, modifies and health-checks software against its ISA criteria so code and spec stay in agreement

Source Download skill
Repository
danielmiessler/LifeOS
Stars
19,682
Licence
MIT
Files
13 files

What it does

When installed, the agent treats software work as a set of written acceptance criteria (an ISA) that must be recorded before code changes, then builds, tests, modifies or audits the app until code and criteria agree. It routes each request to one of four workflows (Build, Test, Modify, Checkup) and sizes the effort to the task. For user-facing work it also expects a reference to compare against and a recorded acceptance verdict before calling anything done.

Great for

  • Developers who already use the LifeOS ISA system and want their agent to keep code and criteria in sync
  • Teams running health checks or audits on apps that have an ISA document
  • Solo builders who want a written spec and test evidence before shipping a feature

Skip it if

  • People who do not use LifeOS or ISA files: the skill assumes the LifeOS folder structure and tools like Assay, Vigil and Errata are present, so it will not work as described without them
  • Quick one-off scripts where the overhead of writing criteria is unwanted; the skill itself says trivial changes still touch the ISA when a project has one
  • Deployments or production data changes: the skill states it does not deploy or write production data and relies on the project's own gated deploy command

Try asking

  • “Build a new CLI tool and write its ISA criteria before implementing it”
  • “Run a health check on my app and explain why these criteria are failing”
  • “Is the code in sync with the ISA? Run the evals before I deploy”
  • “Modify the login behaviour: update the criteria first, then change the code”
Step-by-step guide: how to use LifeOS Development SkillInstall, first run, examples, tips and FAQs

Install in 3 steps

  1. 1

    Download the skill

    The ZIP contains the 13 original files, the MIT licence and an attribution note.

    Development.zip
  2. 2

    Add it to your agent

    Claude Code (all projects)

    mkdir -p ~/.claude/skills && unzip Development.zip -d ~/.claude/skills/

    Claude Code / Agent SDK (this project only)

    mkdir -p .claude/skills && unzip Development.zip -d .claude/skills/

    Claude apps (web/desktop): Settings → Capabilities → Skills → Upload skill, and choose the ZIP.

  3. 3

    Ask for the task

    No special command needed — the agent reads the skill's description and loads it when your request matches. Try one of the prompts above.

Get better results

  • Point the agent at an existing ISA file or let Build create one before asking for code changes, so criteria exist first
  • For user-facing pages, provide a reference screenshot or existing page so the acceptance check has something to compare against
  • Read the script help (Checkup.help.md) and run the tools directly first to see what they report on your repo

What's inside

  • Intents/Build.md
  • Intents/Checkup.md
  • Intents/Modify.md
  • Intents/Test.md
  • References/Guards.md
  • References/Inventory.md
  • References/Sizing.md
  • References/Tools.md
  • SKILL.md
  • Tools/Checkup.help.md
  • Tools/Checkup.ts
  • Tools/Inventory.ts
  • Tools/IsaCheck.ts

Redistributed unmodified from danielmiessler/LifeOS under the MIT licence. The assessment was drafted with AI from the skill's files on 2026-10-29. Skills can instruct your agent to run code — read SKILL.md and any scripts before installing.