local-security

local-security is a skill for Claude Code, Codex from medy-gribkov/arcana. It costs 33 tokens per session (1,872 once invoked), scanned C, original, Apache-2.0.

A set of practices for securing a developer’s computer, including SSH keys, code signing, stored credentials, file permissions, and browser extensions.

In plain words
What is it for?
Use it to create and protect separate SSH keys, manage credentials, check permissions, configure secure connections, and audit workstation tools.
Why use it?
It reduces the chance that a compromised workstation exposes source code, service access, or production credentials.

Skill for Claude CodeCodex

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

Good fit Use it to create and protect separate SSH keys, manage credentials, check permissions, configure secure connections, and audit workstation tools.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/medy-gribkov/arcana/local-security
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 medy-gribkov/arcana --skill local-security
Clone the repo
git clone --depth 1 https://github.com/medy-gribkov/arcana

Made for: Claude Code, Codex.

Its marketplace also offers this one on its own, as the plugin local-security/plugin install local-security after adding the marketplace above.

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 local-security

README.md
[![agentmods](https://agentmods.dev/badge/skills/medy-gribkov/arcana/local-security/github.svg)](https://agentmods.dev/skills/medy-gribkov/arcana/local-security)
Your own site
<a href="https://agentmods.dev/skills/medy-gribkov/arcana/local-security"><img src="https://agentmods.dev/badge/skills/medy-gribkov/arcana/local-security/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 local-security

Your own site · 80×15
<a href="https://agentmods.dev/skills/medy-gribkov/arcana/local-security"><img src="https://agentmods.dev/badge/skills/medy-gribkov/arcana/local-security.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,872 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 4 findings. 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 $0.00033 $0.01872
Opus 5 $0.00016 $0.00936
Sonnet 5 $0.00007 $0.00374
Haiku 4.5 $0.00003 $0.00187

Measured 9d ago against content hash a5320f7f54ed, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade C, and why

local-security scanned grade C with 4 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 9d 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.

Enumerates the file system for secretsmediumData exfiltration

Searching home directories for .env, .ssh, .aws or credential files is reconnaissance for credential theft.

find ~ -maxdepth 3 -name ".netrc" -o -name ".npmrc" -o -name "credentials" \

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

Asks for rootlowPrivilege escalation

A mod that escalates privileges can change anything on the machine, not only the project.

chmod 700 ~/.ssh

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

Reaches for credential filesmediumPrivilege escalation

SSH keys, cloud credentials, git-credentials, .npmrc, /etc/shadow: reading these is how a config file becomes a credential leak.

ssh-keygen -t ed25519 -C "github@workstation" -f ~/.ssh/id_ed25519_github

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

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

curl -H "Authorization: token $GITHUB_TOKEN" https://api.github.com/user
skills/local-security/SKILL.md · 215 lines

How it starts

The opening of the file, as written. The whole thing — 215 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Treat the developer workstation as a critical supply chain node. A compromised dev machine means compromised code, credentials, and infrastructure access. Follow these workflows to harden each surface.

SSH Hardening Workflow

  1. Generate an Ed25519 key per service. One key for GitHub, another for production servers, another for cloud.
  2. Protect the private key with a passphrase. Load it into ssh-agent so you type it once.
  3. Lock permissions on the .ssh directory and all key files.
  4. Configure ~/.ssh/config to use ProxyJump instead of agent forwarding.
  5. Rotate keys annually. Remove old public keys from every authorized service.
# Step 1: Generate a dedicated key
ssh-keygen -t ed25519 -C "github@workstation" -f ~/.ssh/id_ed25519_github

# Step 2: Add to agent with passphrase caching
ssh-add ~/.ssh/id_ed25519_github

# Step 3: Lock permissions
chmod 700 ~/.ssh
chmod 600 ~/.ssh/id_ed25519_*
chmod 644 ~/.ssh/*.pub

# Step 5: Verify fingerprint before trusting a key
ssh-keygen -l -f ~/.ssh/id_ed25519_github.pub

BAD - Single key reused everywhere, no passphrase, open permissions:

ssh-keygen -t rsa -b 2048 -N "" -f ~/.ssh/id_rsa
chmod 755 ~/.ssh
# Same key added to GitHub, AWS, production bastion, personal VPS

GOOD - Dedicated Ed25519 key, passphrase, tight permissions:

ssh-keygen -t ed25519 -C "github@workstation" -f ~/.ssh/id_ed25519_github
chmod 700 ~/.ssh
chmod 600 ~/.ssh/id_ed25519_github

BAD - Agent forwarding to untrusted host:

Host bastion
  HostName bastion.example.com
  ForwardAgent yes

GOOD - ProxyJump through bastion, no agent exposure:

Host bastion
  HostName bastion.example.com

Host production
  HostName 10.0.1.50
  ProxyJump bastion

Windows OpenSSH Agent Setup

# Enable and start the agent service (persists across reboots)
Get-Service ssh-agent | Set-Service -StartupType Automatic
Start-Service ssh-agent

# Add key once
ssh-add $HOME\.ssh\id_ed25519_github

# Point Git to Windows OpenSSH instead of bundled ssh
git config --global core.sshCommand "C:/Windows/System32/OpenSSH/ssh.exe"

# Verify
ssh-add -l

Read the full file on GitHub · 215 lines

Files

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.

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. 9d ago First seen · 215 lines · 33 tokens per session scan C a5320f7f54ed

Subscribe to this mod's changes

local-security is a skill published in the GitHub repository medy-gribkov/arcana (1 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 33 tokens to every session and 1,872 once invoked, about $0.0002 per session on Opus 5. A static security scan graded it C with 4 findings (enumerates the file system for secrets, asks for root, reaches for credential files). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.