<p>I had Claude credits left in my week and wanted to secure my agent-dediced macbook. It
ran on my Mac M1
for a few days while I was on vacation. I made it kind of fancy with Discord support and
remote management through tailscale, it was really fun getting notified every now and
then that another commit was pushed to the open PR.</p>
<p>It used a DIY mvp version of a <a href="https://github.com/snarktank/ralph">Ralph loop</a>.
I am the supply chain! ...The bots tell me they won't draw Simpsons characters for me
and I'm not about to break out an image editor, so we get this footless child instead.</p>
<p>Look at the commits in <a href="https://github.com/kylep/multi/pull/52">this PR</a>, over 80!
A common thing about AI is you get all these impressive stats that way oversell the value
that they represent. These 80 commits are cool but if I'd done it by hands it would have
been like... 4, maybe 5.</p>
<p>As another win, I used my PRD and DD agents from the
<a href="/ai-native-sdlc-first-try.html">prior post</a> to design this out and
that worked wonderfully.</p>
<h2 id="ralph">Ralph?</h2>
<p>Ralph is an autonomous agent pattern that runs Claude Code in a loop
until a task list is empty. The task list here was dynamic, Claude kept looking for new
ways to improve laptop security without hurting agent autonomy. Later it crunched
through security findings from compliance scanners. The agent read each
finding, fixed it through Ansible, verified the fix, and
moved to the next one. I steered it from Discord a bit.</p>
<h1 id="the-setup">The setup</h1>
<p>The machine is a Mac M1 running as an AI workstation. This is "Claude's laptop", and I
factory reset it to remove anything Claude shouldn't have. I segmented it from my
network too, just in case.</p>
<p>Claude Code runs in bypass-permissions mode with
unrestricted tool access. The entire machine config is managed
by an <a href="https://github.com/kylep/multi/tree/main/infra/mac-setup">Ansible playbook</a>,
so any change the agent makes is reproducible on a fresh
install.</p>
<p>Before this project, I'd done some security work setting up pre-commit hooks for
semgrep and gitleaks, a <a href="/ai-security-toolkit.html">security toolkit</a> Docker image, and
hook scripts that blocked known-bad commands.</p>
<h1 id="loop-claude-go-do-security">Loop: Claude, go "do security"</h1>
<p>This loop was <em>okay, I guess</em>. The idea of the loop is really exciting. I can't wait to
get a loop of, like "work on anything in Linear" or something similarly broad that is
able to decompose stuff properly.</p>
<p>Anyways, for this project, the focus was limited to laptop security.
A Python script spawns Claude Code every few minutes to keep in the 5-hour token window.
We never really went above 50%. I had a custom token use mcp counting things up too,
but the math is fuzzy, especially since Claude was offering double quota at night that
week.</p>
<p>Each iteration:</p>
<ol>
<li>Tries to find something to do to improve security (tool or LLM decides)</li>
<li>Pick a finding that hasn't been attempted</li>
<li>Fix it through the Ansible playbook (not ad-hoc shell)</li>
<li>Run the playbook to deploy the fix</li>
<li>Verify the fix took effect</li>
<li>Commit and push</li>
</ol>
<pre class="mermaid">
stateDiagram-v2
    [*] --> Ideate
    Ideate --> PickFinding
    PickFinding --> FixInPlaybook
    FixInPlaybook --> Deploy
    Deploy --> Verify
    Verify --> Commit: pass
    Verify --> PickFinding: fail (retry)
    Commit --> Sleep
    Sleep --> ReadLog
</pre>
<p>The loop had those cost/token controls, a lock file so
only one instance ran at a time, and a timeout per
phase to kill things when they get stuck. It had an adversarial subagent loop, I love those, to
make sure that the changes actually worked, helped security, and did not hurt agent autonomy.
It pushed to GitHub and pinged me on Discord after each verified commit, so I could review from my phone.</p>
<h2 id="llm-only-no-tools">LLM only, no tools</h2>
<blockquote>
<p>"Claude, find me some ways to make my laptop secure and implement the best one through Ansible".</p>
</blockquote>
<p>It found a few real, if basic, issues. Things like:</p>
<ul>
<li>The application firewall was off</li>
<li>A <code>sudoers.d</code> file granted passwordless sudo to the agent user</li>
<li><code>exports.sh</code> and <code>.mcp.json</code> were world-readable (mode 0644)</li>
<li>Screen lock wasn't configured</li>
</ul>
<p>But 60 iterations later, most of the time had gone to things that didn't matter or couldn't work.</p>
<h2 id="the-loop-gets-stuck">The loop gets stuck</h2>
<p>It turns out you need to be proactive about preventing loops.</p>
<p>During this test, Claude spent multiple days iterating on a hook script called <code>protect-sensitive.sh</code>.
It'd move on then just keep coming back for it. The hook itself just tried to prevent the agent from reading sensitive files.
I had given some instructions to not get stuck in loops like that, but I guess it didn't take.</p>
<h2 id="explain-yourself-claude-agent-rcas">Explain Yourself, Claude: Agent RCAs</h2>
<p>After 68 commits in the week, I had Claude run an RCA.</p>
<blockquote>
<p>LLM intuition is a weak security discovery mechanism. The
loop should execute against a scanner's scored finding list,
not improvise the list itself.</p>
</blockquote>
<p>The result Looked really good, 68 commits in 3 days is cool stat, but the actual value
delivered was pretty meh. You need to be really intentional and good about goal-setting.</p>
<p>The RCA asked if it could just use a scanner like I did with the SCA stuff and that
immediately resulted in way more fixes and a much better loop.</p>
<h1 id="scanner-driven-task-lists-are-way-better">Scanner-driven task lists are way better</h1>
<p>The RCA recommended three scanners:</p>
<table>
<thead>
<tr>
<th>Tool</th>
<th>Scope</th>
<th>Why</th>
</tr>
</thead>
<tbody>
<tr>
<td><a href="https://cisofy.com/lynis/">Lynis</a></td>
<td>General system audit</td>
<td>Broad, scored, Linux-first but works on macOS</td>
</tr>
<tr>
<td><a href="https://rkhunter.sourceforge.net/">rkhunter</a></td>
<td>Rootkit detection</td>
<td>Catches things Lynis doesn't check</td>
</tr>
<tr>
<td><a href="https://github.com/usnistgov/macos_security">mSCP</a></td>
<td>macOS CIS Level 1</td>
<td>NIST-maintained, macOS-native compliance checks</td>
</tr>
</tbody>
</table>
<p>All three install through the Ansible playbook. A LaunchDaemon
runs them daily at 06:00 and writes results to
<code>/var/log/security-scans/</code>.</p>
<p>It was admittedly kind of a pain in the ass to help Claude escalate perms to root over
and over during the mSCP thing, some of those tests need root to run and Claude couldn't
trigger them itself.</p>
<h1 id="whatd-it-get-me">What'd it get me?</h1>
<p>Other than the fun of having it work while I was away, here's what Claude tells me it
implemented to secure my laptop from this. Worth noting that this was all done through
Ansible, so when I factory reset my laptop again (I will), I get this back too:</p>
<ul>
<li>Enabled the macOS application firewall and stealth mode to block unsolicited inbound connections</li>
<li>Enabled Gatekeeper to enforce code signing and notarization on all executables</li>
<li>Disabled SSH root login and enforced protocol v2 only</li>
<li>Locked down <code>sshd_config</code> permissions (0600) so it can't be read by other users</li>
<li>Set screen lock to trigger after 10 minutes idle, requiring password immediately</li>
<li>Disabled the guest account entirely</li>
<li>Disabled automatic login</li>
<li>Removed password hints from the login window</li>
<li>Enabled automatic app updates</li>
<li>Disabled AirDrop to prevent unsolicited file transfer attempts</li>
<li>Disabled AirPlay receiver so the machine can't accept screen share requests</li>
<li>Disabled Siri data sharing and search query telemetry</li>
<li>Disabled assistive voice data donation</li>
<li>Disabled diagnostic report submission to Apple</li>
<li>Disabled AI writing tools, mail summaries, Notes transcription, and external intelligence integrations</li>
<li>Disabled personalized advertising</li>
<li>Forced on-device-only dictation (no audio sent to Apple servers)</li>
<li>Enabled secure keyboard entry in Terminal to prevent other processes from reading keystrokes</li>
<li>Installed rkhunter for rootkit detection, running daily</li>
<li>Installed Lynis for system audit scoring, running daily</li>
<li>Installed mSCP for CIS Level 1 compliance checks, running daily</li>
</ul>
<p>So overall, pretty meh. It was fun though and I think if done well and let to run
perpetually, it could be a neat approach to having an agent actively defend my system.</p>


<h2 id="table-of-contents">Table of contents</h2>
<ul>
<li><a href="#claude-code-hooks">Claude Code hooks</a></li>
<li><a href="#how-hooks-work">How hooks work</a></li>
<li><a href="#blocking-destructive-commands">Blocking destructive commands</a></li>
<li><a href="#protecting-sensitive-files">Protecting sensitive files</a></li>
<li><a href="#audit-trail">Audit trail</a></li>
<li><a href="#wiring-it-up">Wiring it up</a></li>
<li><a href="#prompt-injection-defense">Prompt injection defense</a></li>
<li><a href="#why-global-config-not-per-repo">Why global config, not per-repo</a></li>
<li><a href="#same-idea-different-tools">Same idea, different tools</a></li>
</ul>
<h1 id="claude-code-hooks">Claude Code hooks</h1>
<p>Claude Code runs shell commands, reads files, and edits code
on your machine. Hooks let you intercept those actions with
shell scripts that run before or after each tool call. The
scripts get JSON on stdin describing what Claude is about to
do, and they can block it by exiting with code 2.</p>
<p>I set up three hooks: one that blocks destructive commands,
one that blocks access to sensitive files, and one that logs
everything to a JSONL audit trail.</p>
<h1 id="how-hooks-work">How hooks work</h1>
<p>A hook is a shell script registered in
<code>~/.claude/settings.json</code>. There are two lifecycle events:</p>
<ul>
<li><strong>PreToolUse</strong>: runs before Claude executes a tool. Exit 0
to allow, exit 2 to block. The block message goes to stderr.</li>
<li><strong>PostToolUse</strong>: runs after. Good for logging. Can run async
so it doesn't slow things down.</li>
</ul>
<p>Each hook gets a JSON object on stdin with <code>tool_name</code>,
<code>tool_input</code>, <code>session_id</code>, and <code>cwd</code>. You can use <code>jq</code> to
pull out whatever you need.</p>
<p>A <code>matcher</code> field controls which tools trigger the hook. It
takes a regex, so <code>Bash</code> matches only the Bash tool while
<code>Read|Edit|Write|Bash</code> matches all four.</p>
<h1 id="blocking-destructive-commands">Blocking destructive commands</h1>
<p>This one intercepts every Bash tool call and blocks anything
that could wreck the system.</p>
<pre><code class="language-bash">#!/usr/bin/env bash
# ~/.claude/hooks/block-destructive.sh
# PreToolUse hook, matcher: Bash

set -euo pipefail

INPUT=$(cat)
COMMAND=$(echo "$INPUT" | jq -r '.tool_input.command // empty')

if [[ -z "$COMMAND" ]]; then
  exit 0
fi

BLOCKED=""

case "$COMMAND" in
  *"rm -rf /"*|*"rm -rf ~"*)
    BLOCKED="recursive delete of root or home" ;;
  *"git push --force"*|*"git push -f "*)
    BLOCKED="force push" ;;
  *"git reset --hard"*)
    BLOCKED="hard reset" ;;
  *"DROP TABLE"*|*"DROP DATABASE"*)
    BLOCKED="database drop" ;;
  *":(){ :|:&#x26; };:"*)
    BLOCKED="fork bomb" ;;
  *"curl"*"|"*"sh"*|*"curl"*"|"*"bash"*)
    BLOCKED="piped remote execution" ;;
  *"chmod 777"*)
    BLOCKED="world-writable permissions" ;;
  *"mkfs."*)
    BLOCKED="filesystem format" ;;
esac

# Check dd writing to /dev/
if [[ -z "$BLOCKED" ]] &#x26;&#x26; echo "$COMMAND" | \
   grep -qE 'dd\s+if=.*of=/dev/'; then
  BLOCKED="raw device write"
fi

if [[ -n "$BLOCKED" ]]; then
  echo "BLOCKED by block-destructive hook: $BLOCKED" >&#x26;2
  exit 2
fi

exit 0
</code></pre>
<p>Testing it:</p>
<pre><code class="language-bash">$ echo '{"tool_name":"Bash","tool_input":{"command":"rm -rf /"}}' \
  | ~/.claude/hooks/block-destructive.sh
BLOCKED by block-destructive hook: recursive delete of root or home
# exit code: 2

$ echo '{"tool_name":"Bash","tool_input":{"command":"git push --force origin main"}}' \
  | ~/.claude/hooks/block-destructive.sh
BLOCKED by block-destructive hook: force push
# exit code: 2

$ echo '{"tool_name":"Bash","tool_input":{"command":"ls -la"}}' \
  | ~/.claude/hooks/block-destructive.sh
# exit code: 0  (allowed)
</code></pre>
<p>When Claude tries a blocked command, it sees the stderr
message and knows the action was rejected. It can then
rephrase or ask for confirmation.</p>
<h1 id="protecting-sensitive-files">Protecting sensitive files</h1>
<p>The second hook blocks access to credentials, SSH keys, and
cloud configs. It handles both file-path tools (Read, Edit,
Write) and Bash commands that might <code>cat</code> or exfiltrate
those files.</p>
<pre><code class="language-bash">#!/usr/bin/env bash
# ~/.claude/hooks/protect-sensitive.sh
# PreToolUse hook, matcher: Read|Edit|Write|Bash

set -euo pipefail

INPUT=$(cat)
TOOL=$(echo "$INPUT" | jq -r '.tool_name // empty')

check_path() {
  local filepath="$1"
  case "$filepath" in
    */.env|*/.env.*|*.env)
      echo "BLOCKED by protect-sensitive hook: .env file" >&#x26;2
      exit 2 ;;
    */.ssh/id_*)
      echo "BLOCKED by protect-sensitive hook: SSH key" >&#x26;2
      exit 2 ;;
    */.aws/credentials*)
      echo "BLOCKED by protect-sensitive hook: AWS creds" >&#x26;2
      exit 2 ;;
    */.kube/config*)
      echo "BLOCKED by protect-sensitive hook: kubeconfig" >&#x26;2
      exit 2 ;;
  esac
}

if [[ "$TOOL" == "Bash" ]]; then
  COMMAND=$(echo "$INPUT" | jq -r '.tool_input.command // empty')
  if echo "$COMMAND" | \
     grep -qE '(cat|less|head|tail|curl -d @|base64|scp)\s+\.env'; then
    echo "BLOCKED by protect-sensitive hook: .env access via bash" >&#x26;2
    exit 2
  fi
  if echo "$COMMAND" | \
     grep -qE '(cat|less|head|tail)\s+.*(\.ssh/id_|\.aws/credentials|\.kube/config)'; then
    echo "BLOCKED by protect-sensitive hook: sensitive file access via bash" >&#x26;2
    exit 2
  fi
else
  FILEPATH=$(echo "$INPUT" | jq -r '.tool_input.file_path // empty')
  if [[ -n "$FILEPATH" ]]; then
    check_path "$FILEPATH"
  fi
fi

exit 0
</code></pre>
<pre><code class="language-bash">$ echo '{"tool_name":"Read","tool_input":{"file_path":"/home/user/.ssh/id_ed25519"}}' \
  | ~/.claude/hooks/protect-sensitive.sh
BLOCKED by protect-sensitive hook: SSH key
# exit code: 2

$ echo '{"tool_name":"Bash","tool_input":{"command":"cat .env"}}' \
  | ~/.claude/hooks/protect-sensitive.sh
BLOCKED by protect-sensitive hook: .env access via bash
# exit code: 2
</code></pre>
<p>This isn't foolproof. Claude could read a sensitive file
by some path I didn't think of. But it catches the obvious
cases and raises the bar.</p>
<h1 id="audit-trail">Audit trail</h1>
<p>The third hook runs after every tool call and appends a JSON
line to a log file. It runs async so it doesn't slow Claude
down.</p>
<pre><code class="language-bash">#!/usr/bin/env bash
# ~/.claude/hooks/audit-log.sh
# PostToolUse hook, async

LOG="/Users/kp/gh/multi/logs/claude-audit.jsonl"

INPUT=$(cat)
TOOL=$(echo "$INPUT" | jq -r '.tool_name // "unknown"')
SESSION=$(echo "$INPUT" | jq -r '.session_id // "unknown"')
CWD=$(echo "$INPUT" | jq -r '.cwd // "unknown"')

case "$TOOL" in
  Bash)
    PARAM=$(echo "$INPUT" | jq -r '.tool_input.command // empty') ;;
  Read|Edit|Write)
    PARAM=$(echo "$INPUT" | jq -r '.tool_input.file_path // empty') ;;
  *)
    PARAM="" ;;
esac

jq -nc \
  --arg ts "$(date -u +%Y-%m-%dT%H:%M:%SZ)" \
  --arg sid "$SESSION" \
  --arg tool "$TOOL" \
  --arg param "$PARAM" \
  --arg cwd "$CWD" \
  '{timestamp: $ts, session_id: $sid, tool: $tool, param: $param, cwd: $cwd}' \
  >> "$LOG"

exit 0
</code></pre>
<p>After a session, the log looks like:</p>
<pre><code class="language-json">{"timestamp":"2026-03-11T13:14:18Z","session_id":"abc123","tool":"Bash","param":"echo hello","cwd":"/Users/kp/gh/multi"}
</code></pre>
<p>You could pipe this into whatever alerting or analysis you
want. I'm keeping it simple for now, just a file on disk.</p>
<p>The end goal is to use this log to build something like
<a href="https://github.com/ldayton/Dippy">Dippy</a>, a smart
auto-approve hook. Dippy parses bash commands with an AST
and auto-approves safe ones while still prompting for
anything destructive. I want to do the same thing but
trained on my own audit trail, so the approve/deny decisions
reflect how I actually work. That's a future post.</p>
<h1 id="wiring-it-up">Wiring it up</h1>
<p>All three hooks go in <code>~/.claude/settings.json</code> under a
<code>hooks</code> key:</p>
<pre><code class="language-json">{
  "hooks": {
    "PreToolUse": [
      {
        "matcher": "Bash",
        "hooks": [{
          "type": "command",
          "command": "/Users/kp/.claude/hooks/block-destructive.sh"
        }]
      },
      {
        "matcher": "Read|Edit|Write|Bash",
        "hooks": [{
          "type": "command",
          "command": "/Users/kp/.claude/hooks/protect-sensitive.sh"
        }]
      }
    ],
    "PostToolUse": [
      {
        "hooks": [{
          "type": "command",
          "command": "/Users/kp/.claude/hooks/audit-log.sh",
          "async": true
        }]
      }
    ]
  }
}
</code></pre>
<p>Use absolute paths, not <code>~</code>. JSON doesn't expand tilde.</p>
<p>The <code>async: true</code> on the audit hook means Claude doesn't
wait for it to finish before moving on. Logging shouldn't
slow down the workflow.</p>
<p>For a full reference of <code>settings.json</code> options, slash
commands, and CLI flags, the
<a href="/claude-code-cheat-sheet.html">Claude Code CLI Cheat-Sheet</a>
covers all of it.</p>
<h1 id="prompt-injection-defense">Prompt injection defense</h1>
<p>One thing I haven't built yet but plan to: a PostToolUse
hook that scans tool output for prompt injection attempts.</p>
<p>The idea is to grep the output for patterns like "ignore
previous instructions" or "you are now in admin mode" and
flag them. This matters most for tools that ingest external
data. If Claude is reading web pages, parsing documents,
or pulling content from APIs, a malicious payload in that
content could try to hijack the session.</p>
<p>Lasso Security published a
<a href="https://www.lasso.security/blog/prompt-injection-taxonomy-techniques">prompt injection taxonomy</a>
cataloging these techniques: encoding, obfuscation,
role-playing, context manipulation, and more. A PostToolUse
hook is the right place to catch
them because you see the actual content before Claude acts
on it.</p>
<p>I'll cover this in a future post once I have it running on
real workloads.</p>
<h1 id="why-global-config-not-per-repo">Why global config, not per-repo</h1>
<p>Claude Code hooks can be configured at three levels:</p>
<ul>
<li><code>~/.claude/settings.json</code> (global, user-level)</li>
<li><code>.claude/settings.json</code> (per-repo, checked into git)</li>
<li><code>.claude/settings.local.json</code> (per-repo, gitignored)</li>
</ul>
<p>Safety hooks belong in global config. If they're per-repo,
a malicious repository can ship its own <code>.claude/settings.json</code>
that disables your protections or adds hooks that exfiltrate
data. You clone it, run Claude Code, and the repo's hooks
run instead of yours.</p>
<p>This is a real attack vector. In 2025, Check Point Research
found
<a href="https://research.checkpoint.com/2026/rce-and-api-token-exfiltration-through-claude-code-project-files-cve-2025-59536/">CVE-2025-59536</a>:
an attacker plants a <code>.claude/settings.json</code> with hooks in
a repo. You clone it, run Claude Code, approve the trust
dialog (which doesn't mention hooks), and the hook commands
execute immediately. Reverse shell, data exfiltration,
whatever the attacker wants. Anthropic patched it in August
2025, but the lesson stands: keep safety hooks in global
config where only you control them.</p>
<h1 id="same-idea-different-tools">Same idea, different tools</h1>
<p>Claude Code isn't the only AI coding tool with hook support.
Here's how the same concepts map elsewhere.</p>
<table>
<thead>
<tr>
<th>Feature</th>
<th>Claude Code</th>
<th>Cursor</th>
</tr>
</thead>
<tbody>
<tr>
<td>Hook format</td>
<td>Shell scripts</td>
<td>Shell scripts</td>
</tr>
<tr>
<td>Config</td>
<td><code>~/.claude/settings.json</code></td>
<td><code>.cursor/hooks.json</code></td>
</tr>
<tr>
<td>Events</td>
<td><code>PreToolUse</code>, <code>PostToolUse</code></td>
<td><code>preToolUse</code>, <code>postToolUse</code></td>
</tr>
<tr>
<td>Input</td>
<td>JSON on stdin</td>
<td>JSON on stdin</td>
</tr>
<tr>
<td>Block mechanism</td>
<td>Exit code 2 + stderr</td>
<td>Exit code 2 + stderr</td>
</tr>
<tr>
<td>Async support</td>
<td><code>"async": true</code></td>
<td>Not documented</td>
</tr>
</tbody>
</table>
<p>Cursor added hooks in version 1.7 (October 2025) with a
nearly identical model: shell scripts, JSON stdin, exit
codes. It also supports a "prompt" handler type where an
LLM evaluates a natural language condition to allow or deny,
which is interesting but slower. The same shell scripts
could work in both tools with minor config changes.</p>
<p>OpenCode takes a different approach. Instead of shell
scripts, it uses JavaScript or TypeScript plugins placed in
<code>.opencode/plugins/</code> or <code>~/.config/opencode/plugins/</code>. You
register functions on events like <code>tool.execute.before</code> and
<code>tool.execute.after</code>. More powerful (you get full access to
the session and project context), but less portable than a
shell script you can reuse across tools.</p>


<h2 id="table-of-contents">Table of contents</h2>
<ul>
<li><a href="#why-i-dont-trust-the-skill-marketplace">Why I don't trust the skill marketplace</a></li>
<li><a href="#how-openclaw-skills-work">How OpenClaw skills work</a></li>
<li><a href="#the-skill">The skill</a></li>
<li><a href="#one-ai-writing-tools-for-another">One AI writing tools for another</a></li>
<li><a href="#loading-it-into-k8s">Loading it into K8s</a>
<ul>
<li><a href="#injecting-the-api-key">Injecting the API key</a></li>
<li><a href="#mounting-the-skill">Mounting the skill</a></li>
<li><a href="#the-jq-problem">The jq problem</a></li>
<li><a href="#stale-sessions">Stale sessions</a></li>
</ul>
</li>
<li><a href="#talking-to-pai-pericak-ai">Talking to Pai (Pericak AI)</a></li>
</ul>
<h1 id="why-i-dont-trust-the-skill-marketplace">Why I don't trust the skill marketplace</h1>
<p>In the <a href="/openclaw-k8s.html">K8s post</a> I mentioned wanting
to connect OpenClaw to Linear for issue tracking. The
obvious path is ClawHub, OpenClaw's public skill
marketplace. Install a community skill, set your API key,
done. I didn't do that.</p>
<p>In February 2026, a campaign called
<a href="https://cybersecuritynews.com/clawhavoc-poisoned-openclaws-clawhub/">ClawHavoc</a>
compromised ClawHub. Researchers at Trend Micro and Antiy
documented over 1,184 malicious skills that had been
published to the registry. The skills looked legitimate,
had normal names and descriptions, and passed ClawHub's
automated checks. They distributed
<a href="https://www.trendmicro.com/en_us/research/26/b/openclaw-skills-used-to-distribute-atomic-macos-stealer.html">Atomic macOS Stealer</a>,
a credential harvester targeting Keychain, browser
passwords, and crypto wallets.</p>
<p>The publishing bar was low. A one-week-old GitHub account
was enough to push a skill to ClawHub. No code review, no
signing, no sandbox. Once installed, a skill runs inside
the agent process with access to every environment variable
the agent has. That includes API keys, tokens, and anything
else injected via Vault or config.</p>
<p>This is the same pattern that hit npm, PyPI, and VS Code
extensions. A package registry with low friction publishing
and high-privilege execution is a target. ClawHub is no
different.</p>
<p>My approach: write the skill myself, keep it in my repo,
and audit every line. The Linear skill I need is about 150
lines of markdown. That's a small surface to own compared
to trusting a stranger's code with my credentials.</p>
<h1 id="how-openclaw-skills-work">How OpenClaw skills work</h1>
<p>An OpenClaw skill is a directory with a <code>SKILL.md</code> file.
The file has YAML frontmatter (name, description, required
tools and environment variables) and a markdown body with
instructions the agent follows.</p>
<p>There's no compiled code. No dependencies to install. No
background process. The agent reads the markdown, learns
what commands are available, and executes them via bash
when you ask it to. If you want to audit a skill, you read
one file.</p>
<p>Compare this to MCP servers, which are running processes
that the agent connects to over a transport protocol. MCP
servers can do more (stateful connections, streaming), but
they're also harder to audit and have a larger attack
surface. For something like "list my Linear issues," a
static document with curl commands is plenty.</p>
<p>The frontmatter declares what the skill needs:</p>
<pre><code class="language-yaml">---
name: linear
description: Manage Linear issues, projects,
  and comments via the Linear GraphQL API.
metadata: {"openclaw": {"emoji": "📐",
  "requires": {"bins": ["curl"],
  "env": ["LINEAR_API_KEY"]}}}
---
</code></pre>
<p>OpenClaw checks these requirements at load time. If <code>curl</code>
isn't on PATH, or <code>LINEAR_API_KEY</code> isn't set, the skill
doesn't load. No runtime errors, no mysterious failures.</p>
<h1 id="the-skill">The skill</h1>
<p>I had Claude write a Linear skill covering the operations
I actually use: listing issues, creating and updating them,
managing labels, and adding comments. The full skill lives
at <code>apps/openclaw-skills/linear/SKILL.md</code> in my monorepo.</p>
<p>Linear's API is GraphQL-only. No REST endpoints. Every
request is a POST to <code>https://api.linear.app/graphql</code> with
a JSON body containing the query. The skill uses <code>curl</code>
for HTTP. One API key, no OAuth dance.</p>
<p>The auth header is <code>Authorization: $LINEAR_API_KEY</code>.
Linear personal API keys don't use a <code>Bearer</code> prefix.</p>
<p>Here's what listing issues looks like:</p>
<pre><code class="language-bash">curl -s -X POST https://api.linear.app/graphql \
  -H "Content-Type: application/json" \
  -H "Authorization: $LINEAR_API_KEY" \
  -d '{"query": "{ issues(filter: { team: \
    { key: { eq: \"PER\" } } }, first: 25) \
    { nodes { id identifier title \
    state { name } } } }"}'
</code></pre>
<p>And creating an issue:</p>
<pre><code class="language-bash">curl -s -X POST https://api.linear.app/graphql \
  -H "Content-Type: application/json" \
  -H "Authorization: $LINEAR_API_KEY" \
  -d '{"query": "mutation { issueCreate(input: \
    { teamId: \"TEAM_UUID\", \
    title: \"Issue title\", \
    description: \"Issue description\" }) \
    { success issue { id identifier url } } }"}'
</code></pre>
<p>The skill also covers workflow statuses. Changing an
issue's status in Linear means looking up the target
state's UUID first, then passing it to <code>issueUpdate</code>. The
agent chains these naturally: list statuses, find the one
named "Todo", grab its ID, update the issue.</p>
<p>This matches the workflow I described in the
<a href="/linear-mcp.html">Linear MCP post</a>. Nightly agents create
Suggestion issues in Backlog, I promote the good ones to
Todo, working agents pick them up. The skill gives OpenClaw
the same Linear access that Claude Code gets through its
MCP server.</p>
<p>The full skill is about 150 lines of markdown. Ten
operations with copy-paste curl commands and a few compound
examples at the end. I read every line.</p>
<h1 id="one-ai-writing-tools-for-another">One AI writing tools for another</h1>
<p>Claude Code (Opus 4.6) wrote this skill. It read the
Trello skill as a pattern, checked the Linear GraphQL API
docs, and produced a skill that follows the same structure.
One AI building capabilities for another AI.</p>
<p>I described what I wanted at a high level, and Claude
handled the GraphQL query syntax, the jq filters, and the
escape sequences. I reviewed the output. The whole thing
took one conversation.</p>
<p>The skill lives in my monorepo under version control. If
Linear changes their API or I need a new operation, I
update one file.</p>
<h1 id="loading-it-into-k8s">Loading it into K8s</h1>
<p>Getting the skill into the running OpenClaw pod took more
work than writing it. The skill file needs to end up in
the right directory inside the container, the API key
needs to be injected, and OpenClaw needs to discover it.</p>
<h2 id="injecting-the-api-key">Injecting the API key</h2>
<p>I added the Linear API key to Vault alongside the existing
Gemini and Telegram secrets, then updated the Vault Agent
template to export it:</p>
<pre><code class="language-text">{{- with secret "secret/openclaw" -}}
export GEMINI_API_KEY="{{ .Data.data.gemini_api_key }}"
export TELEGRAM_BOT_TOKEN="..."
{{ if .Data.data.linear_api_key }}
export LINEAR_API_KEY="{{ .Data.data.linear_api_key }}"
{{ end }}
{{- end }}
</code></pre>
<h2 id="mounting-the-skill">Mounting the skill</h2>
<p>I stored the SKILL.md in a ConfigMap and mounted it into
the init container. ConfigMap mounts use symlinks
internally, and OpenClaw's skill loader rejects symlinked
paths as a security measure. So the init container copies
the file onto the PVC as a regular file:</p>
<pre><code class="language-yaml">initContainers:
  - name: config-seed
    command: ["sh", "-c"]
    args:
      - |
        # ... existing config seed logic ...
        # Copy skills onto PVC workspace
        mkdir -p /data/workspace/skills/linear
        cp /skill-src/linear/SKILL.md \
          /data/workspace/skills/linear/SKILL.md
    volumeMounts:
      - name: linear-skill
        mountPath: /skill-src/linear
        readOnly: true
</code></pre>
<p>The key detail: skills must live under the workspace
directory (<code>&#x3C;workspace>/skills/</code>), not just anywhere on
the filesystem. OpenClaw's skill discovery only scans
three locations: bundled, managed (<code>~/.openclaw/skills</code>),
and workspace. I initially tried <code>extraDirs</code> and the
managed path. Neither worked until I put it in the
workspace.</p>
<h2 id="the-jq-problem">The jq problem</h2>
<p>The original skill required both <code>curl</code> and <code>jq</code> in its
<code>requires.bins</code> frontmatter. The OpenClaw container has
<code>curl</code> but not <code>jq</code>. The skill gating check runs at
startup: missing binary means the skill silently doesn't
load. Claude dropped <code>jq</code> from the requirements. The agent
is smart enough to parse JSON responses on its own using
the <code>node</code> binary that's already in the container.</p>
<h2 id="stale-sessions">Stale sessions</h2>
<p>After all that, I asked Pai what skills it had. Still
three. OpenClaw snapshots eligible skills when a session
starts and reuses that list for the session's lifetime.
The <code>openclaw agent --message</code> CLI command was reusing an
existing session from before the skill was loaded.
Clearing the sessions directory forced a fresh snapshot:</p>
<pre><code class="language-bash">rm -rf /home/node/.openclaw/agents/main/sessions/*
</code></pre>
<p>After that, the skill appeared.</p>
<h1 id="talking-to-pai-pericak-ai">Talking to Pai (Pericak AI)</h1>
<p>With the skill loaded, Claude Code talked to Pai (the
OpenClaw agent running Gemini 2.5 Flash) through
<code>kubectl exec</code>, using the same pattern from the
<a href="/openclaw-k8s.html">K8s post</a>.</p>
<pre><code class="language-text">Claude: List my Linear teams using the linear skill.
Pai: Your Linear teams are:
  - Pericak (Key: PER)

Claude: List my Linear issues for team PER.
Pai: Here are the Linear issues for team PER:
  - PER-10: ... (State: Backlog)
  - PER-9: ... (State: Todo)
  - PER-8: ... (State: Todo)
  - PER-7: ... (State: Todo)
  - PER-6: ... (State: Todo)
  - PER-5: ... (State: Todo)
  ...
</code></pre>
<p>That's real output (titles redacted). Pai read the
skill's curl commands, called the Linear GraphQL API
with the Vault-injected API key, and returned my actual
issues. The full chain: Claude Code runs <code>kubectl exec</code>,
which calls the <code>openclaw agent</code> CLI, which sends the
message to Gemini 2.5 Flash, which reads the skill, runs
curl against Linear's API, and returns the result.</p>
<p>Two AIs, two different models, coordinating through a
Kubernetes pod with Vault-injected secrets and a
hand-written skill file. The whole thing is auditable
from end to end.</p>
<p>After getting comfortable with how OpenClaw works, I eventually
dropped it and <a href="/openclaw-inspired-assistant.html">built my own assistant from scratch</a>.
Same core ideas, narrower scope, and code I actually understand.</p>


<p>AI coding agents can write code, review PRs, and run tests. They
can't run security scans unless you give them the tools. I built a
Docker image that bundles three scanners into one container, then
wired it into my repo so any AI tool can use them.</p>
<h1 id="whats-in-the-image">What's in the image</h1>
<p>The image <code>kpericak/ai-security-toolkit-1</code> has 3 tools:</p>
<table>
<thead>
<tr>
<th>Category</th>
<th>Tool</th>
</tr>
</thead>
<tbody>
<tr>
<td>SAST (static analysis)</td>
<td><a href="https://semgrep.dev/">semgrep</a></td>
</tr>
<tr>
<td>SCA (dependency vulns)</td>
<td><a href="https://trivy.dev/">trivy</a></td>
</tr>
<tr>
<td>Secrets (files on disk)</td>
<td><a href="https://trivy.dev/">trivy</a></td>
</tr>
<tr>
<td>Secrets (git history)</td>
<td><a href="https://gitleaks.io/">gitleaks</a></td>
</tr>
<tr>
<td>Misconfig (Dockerfile, Terraform)</td>
<td><a href="https://trivy.dev/">trivy</a></td>
</tr>
<tr>
<td>Container image scanning</td>
<td><a href="https://trivy.dev/">trivy</a></td>
</tr>
</tbody>
</table>
<h1 id="the-dockerfile">The Dockerfile</h1>
<p>Multi-stage build. Copy the Go binaries from the official images,
install semgrep via pip on Alpine.</p>
<pre><code class="language-dockerfile">FROM aquasec/trivy:0.69.3 AS trivy
FROM zricethezav/gitleaks:v8.30.0 AS gitleaks

FROM python:3.12.13-alpine

RUN apk upgrade --no-cache &#x26;&#x26; apk add --no-cache nodejs git gcc musl-dev

COPY --from=trivy /usr/local/bin/trivy /usr/local/bin/trivy
COPY --from=gitleaks /usr/bin/gitleaks /usr/local/bin/gitleaks

RUN pip install --no-cache-dir semgrep

COPY .trivyignore /workspace/.trivyignore

RUN addgroup -S scanner &#x26;&#x26; adduser -S scanner -G scanner
RUN mkdir -p /workspace &#x26;&#x26; chown scanner:scanner /workspace

WORKDIR /workspace
USER scanner
ENTRYPOINT ["/bin/sh"]
</code></pre>
<p>Trivy and gitleaks are single Go binaries, so the COPY stages are all they need.
Semgrep needs Python and a C compiler for its native
extensions, which is why <code>gcc</code> and <code>musl-dev</code> are there. The base
images are pinned to specific versions for reproducible builds. A
non-root <code>scanner</code> user runs the tools so the container doesn't
operate as root. The image ends up around 800MB. Not small, but
it's a tooling image, not a production service.</p>
<p>Source:
<a href="https://github.com/kylep/multi/tree/main/infra/ai-security-toolkit-1">GitHub</a></p>
<h1 id="teaching-ai-agents-to-scan">Teaching AI agents to scan</h1>
<p>The scans are just shell commands. The objective is getting robot to run them.
I use <a href="/ruler-cross-tool-ai-rules.html">Ruler</a> to maintain a single
<code>.ruler/security.md</code> file that gets injected into CLAUDE.md,
AGENTS.md, and any other tool-specific config.</p>
<p>Here's the ruler file:</p>
<pre><code class="language-markdown"># Security Scanning

The Docker image `kpericak/ai-security-toolkit-1:0.2` bundles
semgrep, trivy, and gitleaks in one Alpine container.

Run from the repo root. Mount the project directory as /workspace.

## Static analysis (semgrep)
docker run --rm -v "$(pwd):/workspace:ro" \
  kpericak/ai-security-toolkit-1:0.2 \
  -c "semgrep scan --config auto /workspace"

## Vulnerability scanning (trivy)
docker run --rm -v "$(pwd):/workspace:ro" \
  kpericak/ai-security-toolkit-1:0.2 \
  -c "trivy fs --scanners vuln,secret,misconfig /workspace"

## Container image scanning (trivy)
docker run --rm \
  -v /var/run/docker.sock:/var/run/docker.sock \
  kpericak/ai-security-toolkit-1:0.2 \
  -c "trivy image &#x3C;image:tag>"

## Secret scanning (gitleaks)
docker run --rm -v "$(pwd):/workspace:ro" \
  kpericak/ai-security-toolkit-1:0.2 \
  -c "cd /workspace &#x26;&#x26; gitleaks detect --source ."
</code></pre>
<p>After running <code>ruler apply</code>, every AI tool in the repo knows how to
run security scans. I can tell Claude Code "scan this repo for
vulnerabilities" and it has the commands ready.</p>
<h1 id="pre-commit-hooks">Pre-commit hooks</h1>
<p>Both semgrep and gitleaks run as
<a href="https://pre-commit.com/">pre-commit</a> hooks. Every commit gets
a static analysis scan and a secret scan before it lands.</p>
<h2 id="installing-pre-commit">Installing pre-commit</h2>
<p>You need <a href="https://pre-commit.com/">pre-commit</a> installed, plus
Docker for the scanner container.</p>
<pre><code class="language-bash"># macOS
brew install pre-commit

# Linux (pip)
pip install pre-commit

# Then activate hooks in the repo
cd your-repo
pre-commit install
</code></pre>
<p>That wires <code>.pre-commit-config.yaml</code> into <code>.git/hooks/pre-commit</code>
so the hooks run automatically on every commit.</p>
<h2 id="the-hook-config">The hook config</h2>
<pre><code class="language-yaml">- id: semgrep
  name: Semgrep
  description: Static analysis scan using the security toolkit image.
  entry: bash -c 'docker run -v "$(pwd):/workspace:ro" --rm
    kpericak/ai-security-toolkit-1:0.2
    -c "semgrep scan --config auto --error /workspace"'
  language: system
  stages: ["pre-commit", "pre-push"]
- repo: https://github.com/gitleaks/gitleaks
  rev: v8.30.0
  hooks:
    - id: gitleaks
      stages: ["pre-commit", "pre-push"]
</code></pre>
<p>The <code>--error</code> flag on semgrep makes it exit non-zero on findings,
which blocks the commit. Gitleaks uses its official pre-commit
hook, which pre-commit installs via Go. It scans staged files
directly. Use <code>gitleaks detect</code> for full repo scans.</p>
<h1 id="running-the-scans">Running the scans</h1>
<p>Here's what each scanner produces when pointed at this monorepo.</p>
<h2 id="semgrep">semgrep</h2>
<p>The first scan found 43 findings. Most were false positives:
<code>dangerouslySetInnerHTML</code> in the blog's SSG rendering (the HTML
comes from my own markdown), <code>path.join</code> with internal filenames,
K8s manifests in old sample projects, and vendored Prism.js.</p>
<p>Two changes got it to zero:</p>
<ol>
<li>A <code>.semgrepignore</code> file to skip directories that aren't active
code: <code>samples/</code>, old infra, vendored JS, and a legacy project.</li>
<li>Inline <code>// nosemgrep</code> comments on the few remaining lines where
the finding is a known false positive, like the SSG innerHTML.</li>
</ol>
<pre><code>┌──────────────┐
│ Scan Summary │
└──────────────┘
Ran 717 rules on 485 files: 0 findings.
</code></pre>
<p>Zero findings means semgrep can run as a pre-commit hook with
<code>--error</code> and block on any new issue. No triage fatigue.</p>
<h2 id="trivy">trivy</h2>
<p>Trivy's default scanners are <code>vuln</code> and <code>secret</code>. It also has
<code>misconfig</code> and <code>license</code> scanners. Adding <code>--scanners vuln,secret,misconfig</code> enables Dockerfile and Terraform
misconfiguration checks on top of the dependency and secret
scanning.</p>
<p>The first scan found 7 npm vulnerabilities. 3 HIGH in Next.js
14 (DoS in server components), plus medium/low hits in
dompurify, lodash-es, and diff. I bumped Next.js from 14 to 15
and ran <code>npm audit fix</code> for the transitive deps. The upgrade
required no code changes. Pages Router, <code>output: 'export'</code>, and
React 18 all still work on Next.js 15.</p>
<p>With misconfig enabled, trivy also flagged Dockerfile issues:
no non-root USER, <code>cd</code> instead of <code>WORKDIR</code>, missing
HEALTHCHECK. The kind of things you'd catch in a code review
but might miss if nobody's looking.</p>
<pre><code>Report Summary
┌────────────────────────────────────────┬────────────┬───────┬─────────┬───────────────────┐
│                 Target                 │    Type    │ Vulns │ Secrets │ Misconfigurations │
├────────────────────────────────────────┼────────────┼───────┼─────────┼───────────────────┤
│ apps/blog/blog/package-lock.json       │    npm     │   0   │    -    │         -         │
├────────────────────────────────────────┼────────────┼───────┼─────────┼───────────────────┤
│ apps/blog/Dockerfile                   │ dockerfile │   -   │    -    │         3         │
├────────────────────────────────────────┼────────────┼───────┼─────────┼───────────────────┤
│ apps/blog/tf                           │ terraform  │   -   │    -    │         0         │
├────────────────────────────────────────┼────────────┼───────┼─────────┼───────────────────┤
│ infra/ai-security-toolkit-1/Dockerfile │ dockerfile │   -   │    -    │         1         │
└────────────────────────────────────────┴────────────┴───────┴─────────┴───────────────────┘
</code></pre>
<p>Zero dependency vulns. The Dockerfile misconfigs are real
findings to fix next. The policy going forward: keep SCA vulns
at 0 in active projects. Major package upgrades are acceptable
to get there. Playwright tests catch regressions from the
upgrades.</p>
<h2 id="trivy-image">trivy image</h2>
<p><code>trivy fs</code> scans source code and lock files. <code>trivy image</code>
scans a built Docker image, catching OS-level CVEs in the base
image and vulnerabilities in installed packages that don't show
up in any lock file.</p>
<p>Running it against the first version of the toolkit image found
25 vulnerabilities that <code>trivy fs</code> never saw: Alpine OS
packages, Python dependencies, and Go stdlib CVEs baked into
the trivy and gitleaks binaries.</p>
<p>Fixes for v0.2:</p>
<ol>
<li>Pinned <code>python:3.12.13-alpine</code> and added <code>apk upgrade</code> to
get the latest Alpine packages. Fixed the CRITICAL zlib CVE.</li>
<li>The Go stdlib CVEs live inside the gitleaks binary, compiled
with Go 1.25.4. No newer gitleaks release exists. Added a
<code>.trivyignore</code> with comments explaining each suppression.</li>
</ol>
<p>The policy: no HIGH or CRITICAL findings. MEDIUM and below from
upstream binaries we don't compile are accepted and documented.</p>
<h2 id="gitleaks">gitleaks</h2>
<pre><code>144 commits scanned.
no leaks found.
</code></pre>
<p>Clean. Gitleaks scans git history by default, so it catches
secrets that were committed and later deleted. Trivy also has
a secret scanner, but it only checks files on disk. If someone
committed an API key and removed it in the next commit, trivy
wouldn't see it. Gitleaks would, because the key is still in
the git log. Found one in history? <a href="/git-reference.html">Git filter-branch</a> scrubs it.</p>
<p>That's why both are in the image. Trivy covers dependency vulns
and current-file secrets. Gitleaks covers the git history angle.
I originally had <code>npm audit</code> in the image too, but dropped it
since trivy already scans <code>package-lock.json</code> for the same CVEs.</p>
<h1 id="the-workflow">The workflow</h1>
<p>With all this wired up, security scanning happens at three levels:</p>
<ol>
<li><strong>Every commit</strong>: semgrep and gitleaks run as pre-commit hooks.
Any new static analysis finding or leaked secret blocks the
commit.</li>
<li><strong>Scheduled</strong>: a security agent runs <code>trivy image</code> against
built container images on a schedule, triages the results,
and files issues in
<a href="/linear-mcp.html">Linear</a> for anything that needs attention.
Image scanning is too slow for pre-commit hooks but catches
OS-level CVEs that filesystem scans miss.</li>
<li><strong>On demand</strong>: I tell the AI agent "run security scans" or
include it in task instructions. The agent runs the docker
commands from its CLAUDE.md context and triages the output.</li>
</ol>
<p>The AI agent is good at triaging scan results. It can reason about
which dependency vulnerabilities actually matter for a static
export vs a running server. That's the real value of combining
scanners with AI agents: the agent reads the output instead of
just dumping a report.</p>
<p>If you want to apply the same approach to code quality, I built a
<a href="/ai-lint-toolkit.html">lint toolkit</a> that bundles ruff, biome,
hadolint, and tflint in the same Docker-based setup.</p>


Kyle Pericak

Ralph Secure My Laptop

Safety Hooks for Claude Code

Writing My Own OpenClaw Skill for Linear

Trying to Secure OpenClaw using Kubernetes

Security Toolkit for AI Agents