LifeOS is an AI-assisted personal operating system that records a person’s goals, values, context, and current situation to help move them toward a desired future state. It supports work such as building applications, starting businesses, and creative projects. Its catalogue entries extend the system through skills, hooks, agents, and commands.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add danielmiessler/LifeOS --skill hardeninggit clone --depth 1 https://github.com/danielmiessler/LifeOSWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/danielmiessler/lifeos/hardening)<a href="https://agentmods.dev/skills/danielmiessler/lifeos/hardening"><img src="https://agentmods.dev/badge/skills/danielmiessler/lifeos/hardening/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/danielmiessler/lifeos/hardening"><img src="https://agentmods.dev/badge/skills/danielmiessler/lifeos/hardening.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00141 | $0.01358 |
| Opus 5.5 | $0.00056 | $0.00543 |
| Sonnet 5.5 | $0.00028 | $0.00272 |
| Haiku 4.5 | $0.00014 | $0.00136 |
Grade A, and why
Hardening scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 69 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Hardening Skill
What It Does
Hardening sharpens what already exists — tests, ISCs, and code — without adding new functionality. Five workflows target test-surface and code-surface robustness: property-based testing via fast-check, mutation testing via Stryker, CRAP-complexity scoring, DRY duplication detection, and acceptance-test mutation that perturbs ISC text to catch fluff.
The Problem
Example-based tests check a handful of inputs the author thought of, so the bugs that survive are the inputs the author didn't think of. A test suite can be green and still be weak. ISCs can read as crisp pass/fail and still be fluff that anything would satisfy. You can't see any of this by reading the tests — you need to test the tests. This skill mechanizes that: property tests express the universal claim and shrink failures to the minimal counterexample, mutation testing proves the suite catches injected bugs, and acceptance-test mutation proves each ISC actually constrains the work.
How It Works
Hardening techniques sharpen what already exists — tests, ISCs, code. They don't add new functionality. Five workflows, all targeting test-surface and code-surface robustness.
Workflow Routing
| Workflow | Trigger | File |
|---|---|---|
| PropertyTest | property test, property based testing, PBT, fast-check, universal quantified claim, shrink counterexample — pure functions, parsers, serializers, data transforms, invariants | Workflows/PropertyTest.md |
| MutationTest | mutation test, mutation testing, Stryker, test the tests | — planned, not yet built (stub; see Status) |
| CrapAnalysis | CRAP score, CRAP analysis, risky undertested code | — planned, not yet built (stub; see Status) |
| DryAnalysis | DRY scan, jscpd, duplication rot | — planned, not yet built (stub; see Status) |
| AcceptanceTestMutation | acceptance test mutation, sharpen ISCs, detect fluff ISCs | — planned, not yet built (stub; see Status) |
Doctrine
These workflows operate against the existing test surface. PropertyTest doesn't replace bun-test examples — properties express the universal claim, examples are sampled instances of it. MutationTest doesn't replace test authoring — it grades existing tests' robustness. CRAP and DRY don't add tests — they prioritize where to add them. Acceptance-test mutation doesn't add ISCs — it mechanizes the Fluff vs Load-bearing distinction from ISAFormat.md.
What ships with it
1 file beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 69 lines · 141 tokens per session scan A ded92c1da67e
Hardening is a skill published in the GitHub repository danielmiessler/LifeOS (19,557 stars, last pushed 1mo ago), licensed MIT. It adds 141 tokens to every session and 1,358 once invoked, about $0.0006 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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