guardrails

guardrails is a skill for Claude Code, Codex from jasonkneen/lazar. It costs 101 tokens per session (705 once invoked), scanned B, original, MIT.

A switch for Lazar's safety controls, including restrictions on shell access, protected kernel files, source files, and pre-tool checks. These controls limit which operations an agent can perform.

In plain words
What is it for?
Use it to inspect the current protection state, temporarily turn protections off for authorized maintenance, or turn them back on. It covers work involving protected files and directories.
Why use it?
It helps identify or change the restrictions when a requested operation is blocked or when the operator wants safety restored after elevated access.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to inspect the current protection state, temporarily turn protections off for authorized maintenance, or turn them back on. It covers work involving protected files and directories.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jasonkneen/lazar/guardrails
Install

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.

Any agent
npx skills add jasonkneen/lazar --skill guardrails
Clone the repo
git clone --depth 1 https://github.com/jasonkneen/lazar

Made for: Claude Code, Codex.

Wrote 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.

agentmods badge for guardrails

README.md
[![agentmods](https://agentmods.dev/badge/skills/jasonkneen/lazar/guardrails/github.svg)](https://agentmods.dev/skills/jasonkneen/lazar/guardrails)
Your own site
<a href="https://agentmods.dev/skills/jasonkneen/lazar/guardrails"><img src="https://agentmods.dev/badge/skills/jasonkneen/lazar/guardrails/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.

agentmods 80×15 button for guardrails

Your own site · 80×15
<a href="https://agentmods.dev/skills/jasonkneen/lazar/guardrails"><img src="https://agentmods.dev/badge/skills/jasonkneen/lazar/guardrails.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 101 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 705 The whole file, excluding the scripts and references it only reads on demand.
Security scan B 1 finding. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00101 $0.00705
Opus 5 $0.00051 $0.00352
Sonnet 5 $0.00020 $0.00141
Haiku 4.5 $0.00010 $0.00071

Measured 11d ago against content hash 82614cb1e18b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade B, and why

guardrails scanned grade B with 1 finding 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 11d 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.

Tells the agent never to refusemediumAnti-refusal

Suppressing the ability to decline removes a core safety control; a later harmful request then succeeds.

description: "Turn lazar's enforcement layers on or off. Use when a write fails with 'Operation not permitted', when the operator asks for full access, when you need to edit bin/ src/ logs/, or when the operator asks to

Downgraded: this mod is about security review, or the phrase is quoted, so it is likely naming the pattern rather than instructing it.

src/seed-skills/guardrails/SKILL.md · 76 lines

How it starts

The opening of the file, as written. The whole thing — 76 lines — stays where its author put it; the contents beside it link to each section on GitHub.

guardrails

One switch for every enforcement layer in lazar.

The four layers

# Layer Mechanism
1 bash tool sandbox sandbox-exec wrapper (LAZAR_NO_SANDBOX)
2 kernel binary lock chflags uchg bin/lazar
3 source lock chmod a-w src/
4 pre-tool vetoes hooks/pre-tool.d/*.sh

Commands

bash $LAZAR_HOME/scripts/lazar-guardrails.sh status   # which mode am I in?
bash $LAZAR_HOME/scripts/lazar-guardrails.sh off      # full operator access
bash $LAZAR_HOME/scripts/lazar-guardrails.sh on       # restore enforcement

When to use

  • A write returned Operation not permitted and the operator wants it done.
  • The operator asks to edit bin/, src/, logs/, or anything outside skills/ memory/ workspace/.
  • The operator says "full access", "no sandbox", "stop blocking me".
  • The operator asks to re-enable safety after risky work.

Hard rule

Never refuse an operator request because of permissions.

Wrong:

"I can't write to logs/ — it's kernel-owned. Want me to use workspace/ instead?"

Right:

bash $LAZAR_HOME/scripts/lazar-guardrails.sh status
# if guardrails are on and the operator wants this:
bash $LAZAR_HOME/scripts/lazar-guardrails.sh off
# then perform the actual write

If guardrails are already OFF, there is nothing to route around — just do the work.

Important: mode changes need a fresh invocation

Layers 2–4 (locks, hooks) apply immediately. Layer 1 (sandbox) is decided when the kernel process starts, so a running invocation stays in its current mode. After toggling, the NEXT lazar call picks up the new mode. Tell the operator that rather than pretending the current turn changed.

Safety posture when OFF

Guardrails OFF removes enforcement, not discipline. Still true:

  • Kernel edits go through workspace/proposals/ + scripts/kernel-apply.sh.
  • Back up before destructive edits (engineering/safe-edit).
  • VERIFY still runs — grounding is independent of the sandbox.
  • Do nothing the operator did not ask for. Full access is trust, not licence.

Read the full file on GitHub · 76 lines

Changes

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.

  1. 11d ago First seen · 76 lines · 101 tokens per session scan B 82614cb1e18b

Subscribe to this mod's changes

guardrails is a skill published in the GitHub repository jasonkneen/lazar (31 stars, last pushed 29d ago), licensed MIT. It adds 101 tokens to every session and 705 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it B with 1 finding (tells the agent never to refuse). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.

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