security-and-hardening
security-and-hardening is a skill in addyosmani/agent-skills, last changed 3 Oct 2026. It can touch credentials, run shell commands, reach the network and name web addresses — read the findings before installing. Our pattern check flagged nothing at commit aeac41d on 26 Oct 2026.
Pattern check: nothing flagged · commit aeac41d · 26 Oct 2026
InstallHardens code against vulnerabilities. Use when auditing an input handler for vulnerabilities, when handling user input, authentication, data storage, or external integrations, or when checking a login flow is safe against the OWASP Top Ten. Use when building any feature that accepts untrusted data, manages user sessions, or interacts with third-party services. Use when auditing dependencies for known vulnerabilities, triaging package-manager audit findings, or assessing supply-chain risk in a new package. Use when personal data or privacy compliance (GDPR, CCPA) is involved.
- Licence
- MIT
- Repo stars
- 110.9k
- Folder last changed
- 3 Oct 2026 (opens in a new tab)
- Publisher
- addyosmani
- Files
- 2 files
- Checked
- aeac41d (opens in a new tab) · 26 Oct 2026
Install
Each tab says whether it installs commit aeac41d, the one we checked, or the latest version.
No tab for your agent? Use Any agent for OpenCode, Goose, Windsurf (Devin Desktop), Zed, Roo Code, Factory Droid, Junie, Amp and Antigravity, and Claude Code for Cline. Kiro needs the folder copied by hand.
Pinned to commit aeac41d, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&
git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/addyosmani/agent-skills.git "$tmp" &&
git -C "$tmp" fetch -q --depth 1 origin aeac41d4d005999432bb7312f7ff06383a91d59d &&
git -C "$tmp" sparse-checkout set -- skills/security-and-hardening &&
git -C "$tmp" checkout -q aeac41d4d005999432bb7312f7ff06383a91d59d &&
mkdir -p .claude/skills &&
mkdir .claude/skills/security-and-hardening &&
cp -R "$tmp"/skills/security-and-hardening/. .claude/skills/security-and-hardening/ &&
rm -rf "$tmp"If Claude Code was already running and this created the skills folder, run /reload-skills.
Or install the agent-skills plugin it ships in. Installs the latest version, not the one we checked. Installs everything in the plugin, including any hooks, MCP servers and scripts our check doesn't cover.
claude plugin marketplace add addyosmani/agent-skills --scope project &&
claude plugin install agent-skills@addy-agent-skills --scope projectPinned to commit aeac41d, the one we checked.
Skills in the Claude apps belong to your account rather than to a project.
Make security-and-hardening.zip, with the skill folder at the top level:
tmp="$(mktemp -d)" &&
git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/addyosmani/agent-skills.git "$tmp" &&
git -C "$tmp" fetch -q --depth 1 origin aeac41d4d005999432bb7312f7ff06383a91d59d &&
git -C "$tmp" sparse-checkout set -- skills/security-and-hardening &&
git -C "$tmp" checkout -q aeac41d4d005999432bb7312f7ff06383a91d59d &&
out="$(mktemp -d)" &&
cp -R "$tmp"/skills/security-and-hardening "$out"/security-and-hardening &&
(cd "$out" && zip -qr - security-and-hardening) > security-and-hardening.zip &&
rm -rf "$tmp" "$out"In Claude, open Customize > Skills, select +, then + Create skill > Upload a skill, and choose security-and-hardening.zip.
On Free, Pro and Max plans, turn on Code execution and file creation (Create and edit files in newer settings) under Settings > Capabilities.
Pinned to commit aeac41d, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&
git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/addyosmani/agent-skills.git "$tmp" &&
git -C "$tmp" fetch -q --depth 1 origin aeac41d4d005999432bb7312f7ff06383a91d59d &&
git -C "$tmp" sparse-checkout set -- skills/security-and-hardening &&
git -C "$tmp" checkout -q aeac41d4d005999432bb7312f7ff06383a91d59d &&
mkdir -p .agents/skills &&
mkdir .agents/skills/security-and-hardening &&
cp -R "$tmp"/skills/security-and-hardening/. .agents/skills/security-and-hardening/ &&
rm -rf "$tmp"Codex picks up new skills on its own; restart it if this one does not appear.
Pinned to commit aeac41d, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&
git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/addyosmani/agent-skills.git "$tmp" &&
git -C "$tmp" fetch -q --depth 1 origin aeac41d4d005999432bb7312f7ff06383a91d59d &&
git -C "$tmp" sparse-checkout set -- skills/security-and-hardening &&
git -C "$tmp" checkout -q aeac41d4d005999432bb7312f7ff06383a91d59d &&
mkdir -p .cursor/skills &&
mkdir .cursor/skills/security-and-hardening &&
cp -R "$tmp"/skills/security-and-hardening/. .cursor/skills/security-and-hardening/ &&
rm -rf "$tmp"Pinned to commit aeac41d, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&
git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/addyosmani/agent-skills.git "$tmp" &&
git -C "$tmp" fetch -q --depth 1 origin aeac41d4d005999432bb7312f7ff06383a91d59d &&
git -C "$tmp" sparse-checkout set -- skills/security-and-hardening &&
git -C "$tmp" checkout -q aeac41d4d005999432bb7312f7ff06383a91d59d &&
mkdir -p .github/skills &&
mkdir .github/skills/security-and-hardening &&
cp -R "$tmp"/skills/security-and-hardening/. .github/skills/security-and-hardening/ &&
rm -rf "$tmp"In a running Copilot CLI session, run /skills reload.
Or install it with gh skill, which also installs the commit we checked. Needs GitHub CLI 2.90 or later.
gh skill install addyosmani/agent-skills skills/security-and-hardening/SKILL.md@aeac41d4d005999432bb7312f7ff06383a91d59d --agent github-copilot --scope projectPinned to commit aeac41d, the one we checked.
From your project's root folder:
tmp="$(mktemp -d)" &&
git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/addyosmani/agent-skills.git "$tmp" &&
git -C "$tmp" fetch -q --depth 1 origin aeac41d4d005999432bb7312f7ff06383a91d59d &&
git -C "$tmp" sparse-checkout set -- skills/security-and-hardening &&
git -C "$tmp" checkout -q aeac41d4d005999432bb7312f7ff06383a91d59d &&
mkdir -p .gemini/skills &&
mkdir .gemini/skills/security-and-hardening &&
cp -R "$tmp"/skills/security-and-hardening/. .gemini/skills/security-and-hardening/ &&
rm -rf "$tmp"In a running session, run /skills reload.
Or use Gemini CLI’s own installer. Installs the latest version, not the one we checked.
gemini skills install https://github.com/addyosmani/agent-skills.git --path skills/security-and-hardening --scope workspacePinned to commit aeac41d, the one we checked.
Codex, Cursor, Copilot, VS Code, Gemini CLI, OpenCode, Goose, Amp and Zed all read .agents/skills; Claude Code and Kiro list only their own folders.
From your project's root folder:
tmp="$(mktemp -d)" &&
git clone -q --depth 1 --filter=blob:none --no-checkout https://github.com/addyosmani/agent-skills.git "$tmp" &&
git -C "$tmp" fetch -q --depth 1 origin aeac41d4d005999432bb7312f7ff06383a91d59d &&
git -C "$tmp" sparse-checkout set -- skills/security-and-hardening &&
git -C "$tmp" checkout -q aeac41d4d005999432bb7312f7ff06383a91d59d &&
mkdir -p .agents/skills &&
mkdir .agents/skills/security-and-hardening &&
cp -R "$tmp"/skills/security-and-hardening/. .agents/skills/security-and-hardening/ &&
rm -rf "$tmp"Or use the skills CLI from skills.sh. Installs the latest version, not the one we checked. The skills CLI reports installs to skills.sh unless you set DISABLE_TELEMETRY=1.
npx skills@1.7.4 add addyosmani/agent-skills --skill security-and-hardeningWhat it can touch
From the files and frontmatter at commit aeac41d. This is how much a skill can do, not whether it is risky.
What it can touch: Shell, network or credentials
Runs shell commands
Its instructions or files give the agent commands to run on your computer.
Reaches the network
It sends or fetches data over the internet, for example with curl, an HTTP library or a package install.
Names web addresses
It mentions outside web addresses the agent may visit. We list them but don't follow them.
Touches credentials
It reads, asks for or contains keys, tokens, passwords or similar secrets.
references/hardening-patterns.md:150 · SKILL.md:111
Pattern check
Pattern check: nothing flagged · commit aeac41d · 26 Oct 2026
We checked every text file in this skill, at commit aeac41d on 26 Oct 2026, against 45 published patterns such as download-and-run commands, hidden text and credential access. We don't run the skill, we don't read the web pages it points to, and we can't judge everything its instructions might lead an agent to do. In published tests, pattern checks like this one missed most malicious skills. Read the skill before you install it — especially anything it asks you to download or run.
How the check worksReport an incorrect finding
Outside links we did not follow
- https://genai.owasp.org/llm-top-10/
Format check
Each agent reads SKILL.md a little differently. We check the file against each one's published rules; we don't run the skill in any agent.
Agent Skills specPasses
The open format from agentskills.io, held to what the strictest agents enforce, so one folder loads everywhere.
- Note
There is no license field, so readers can't tell whether they may reuse the skill. O2
Fix: Add license: with an SPDX name such as MIT or Apache-2.0, or the name of a bundled licence file.
- Note
Reference files over 100 lines with no table of contents at the top: references/hardening-patterns.md (325 lines). B5
Fix: Add a short list of the sections at the top of each.
- Note
Claude CodePasses
Claude Code reads its own extra fields, ignores unknown ones, and still loads a skill whose frontmatter is broken, without its fields.
- Note
Reference files over 100 lines with no table of contents at the top: references/hardening-patterns.md (325 lines). B5
Fix: Add a short list of the sections at the top of each.
- Note
Claude apps & API uploadPasses
Uploading to claude.ai or the Claude API, or packaging with Anthropic's script, accepts only the six spec fields and stops on anything else.
- Note
The description is 581 characters. The claude.ai Help Center says 200 at most, though Anthropic's API docs and validator allow 1,024. D4
Fix: If the claude.ai upload refuses it, trim the description to 200 characters.
- Note
Reference files over 100 lines with no table of contents at the top: references/hardening-patterns.md (325 lines). B5
Fix: Add a short list of the sections at the top of each.
- Note
- OpenAI (Codex & API)Passes
- VS Code & CopilotPasses
SKILL.md
Files
2 files
| Path | Size |
|---|---|
| SKILL.md (opens in a new tab) | 17.1 KB |
| references/hardening-patterns.md (opens in a new tab) | 12.7 KB |
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