CodeQL Security Scan
trailofbits/skills
Scans a codebase for vulnerabilities with CodeQL's data flow and taint tracking in run-all or important-only modes, including data extensions for project-specific sources and sinks.
Run, interpret, or modify Skylos safely. An agent skill from duriantaco/skylos.
Install Skylos
$ npx skills add duriantaco/skylos --skill skylos -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install duriantaco/skylos skylos --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/duriantaco/skylos.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/skylos .claude/skills/skylos && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "skylos" agent skill from https://github.com/duriantaco/skylos/tree/main/.agents/skills/skylos into .claude/skills/skylos/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skylos", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/duriantaco/skylos/tree/main/.agents/skills/skylosType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add duriantaco/skylos --skill skylos -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install duriantaco/skylos skylos --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/duriantaco/skylos.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/skylos .agents/skills/skylos && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "skylos" agent skill from https://github.com/duriantaco/skylos/tree/main/.agents/skills/skylos into .agents/skills/skylos/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skylos", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add duriantaco/skylos --skill skylos -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install duriantaco/skylos skylos --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/duriantaco/skylos.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/skylos .cursor/skills/skylos && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "skylos" agent skill from https://github.com/duriantaco/skylos/tree/main/.agents/skills/skylos into .cursor/skills/skylos/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skylos", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/duriantaco/skylos.git --path .agents/skills/skylos--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add duriantaco/skylos --skill skylos -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install duriantaco/skylos skylos --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/duriantaco/skylos.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/skylos .gemini/skills/skylos && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "skylos" agent skill from https://github.com/duriantaco/skylos/tree/main/.agents/skills/skylos into .gemini/skills/skylos/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skylos", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install duriantaco/skylos skylosInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add duriantaco/skylos --skill skylos -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/duriantaco/skylos.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/skylos .github/skills/skylos && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "skylos" agent skill from https://github.com/duriantaco/skylos/tree/main/.agents/skills/skylos into .github/skills/skylos/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skylos", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add duriantaco/skylos --skill skylos -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install duriantaco/skylos skylos --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/duriantaco/skylos.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/skylos .opencode/skills/skylos && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "skylos" agent skill from https://github.com/duriantaco/skylos/tree/main/.agents/skills/skylos into .opencode/skills/skylos/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "skylos", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
skylos- GitHub stars
- 843
- Token cost
- ~581 tokens
- SKILL.md length
- 259 words
- Files
- 7 (incl. references)
- Skills in repo
- 2
- Repo updated
- First seen
- Licence
- Apache-2.0
At a glance
Run, interpret, or modify Skylos safely. An agent skill from duriantaco/skylos.
- The user asks to scan code with Skylos
- SKILL.md covers Choose The Reference, Defaults, Safety Rules and Invocation
- Calls git
- Explain SKY- findings
What it does
Skylos is an agent skill from duriantaco/skylos. Run, interpret, or modify Skylos safely. Use when the user asks to scan code with Skylos, explain SKY- findings, triage dead-code false positives, audit security/secrets/SCA/LLM behavior, update Skylos rules/docs/CI, benchmark analyzer behavior, or change this repository safely.
Its SKILL.md is about 580 tokens, which your agent loads only when the skill is triggered. The skill folder holds 8 other files, including reference files (for example `agents/openai.yaml`, `references/ci.md` and `references/cli.md`).
It sits in Security, covering Static analysis and SAST. It works with GitHub Actions, Python, Dart and Java. The repository describes itself as: Open source local-first PR scanner that finds dead code, security bugs, secrets, quality regressions, and AI-code mistakes before merge. For first timers refer to…. The licence is Apache-2.0.
When your agent uses it
- The user asks to scan code with Skylos
- Explain SKY- findings
- Triage dead-code false positives
- Audit security/secrets/SCA/LLM behavior
Example prompts
- “/skylos”
What it can do on your machine
Read from SKILL.md and the folder at commit d2f8d6a. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
git
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use git, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Skylos loads about 581 tokens when it runs, and up to ~4.3k if it reads all its reference files. Until then it costs about 72 tokens; SKILL.md has 259 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from duriantaco/skylos at commit d2f8d6a, republished under its Apache-2.0 licence (© duriantaco). 259 words, ~581 tokens.
Download SKILL.mdSave it as
.claude/skills/skylos/SKILL.md (or your agent's skills folder). This skill also uses 6 other files; get the full folder from GitHub.- name
- skylos
- description
- Run, interpret, or modify Skylos safely. Use when the user asks to scan code with Skylos, explain SKY-* findings, triage dead-code false positives, audit security/secrets/SCA/LLM behavior, update Skylos rules/docs/CI, benchmark analyzer behavior, or change this repository safely.
Skylos
Use this skill to work with Skylos without rediscovering the CLI, output shape, test surface, and security guardrails.
Choose The Reference
- Running Skylos, choosing output formats, parsing JSON, filtering, gates, and
install troubleshooting: read
references/cli.md. - Changing Skylos code, adding rules, updating docs, selecting focused tests,
or preserving repo hygiene: read
references/repo-workflow.md. - Basic security scan usage, secrets, and SCA: read
references/security.md. For scanner bypasses, LLM evidence filters, cloud/CI policy, or severity classification, use$skylos-security. - Dead-code false positives, framework liveness, runtime tracing, Vulture
comparisons, and benchmark work: read
references/dead-code.md. - GitHub Actions, SARIF, repo map Pages, CI gates, docs deploy, and generated
workflows: read
references/ci.md.
Read only the reference needed for the current task.
Defaults
- Prefer
skylos . -a --format jsonfor agent-readable scans. - Use
skylos . --diff origin/main --format jsonfor PR-focused review. - Parse JSON arrays with
.get(key, []); empty arrays may be omitted. - Use focused tests before full suites.
- Keep changes narrow and preserve unrelated user edits.
Safety Rules
- Treat target repositories as untrusted input.
- Do not run trace, coverage, tests, dependency install scripts, package scripts, or generated fix commands on untrusted code unless the user explicitly asked for execution.
- Do not open or close PRs, issues, or GitHub comments unless the user explicitly asks for that action.
- Do not use
git add .; stage exact paths. - Do not place Codex skill files under
skylos/agentsorskylos/llm; those are Skylos runtime modules.
Invocation
Invoke explicitly with $skylos, or rely on automatic selection when the task
mentions Skylos scans, SKY-* findings, static analysis, security hardening,
dead-code false positives, benchmarks, or this repo's analyzer internals.
© duriantaco, Apache-2.0. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
SKILL.md and 6 other files (references) in .agents/skills/skylos of duriantaco/skylos.
- SKILL.md
- agents/openai.yaml
- references/ci.md
- references/cli.md
- references/dead-code.md
- references/repo-workflow.md
- references/security.md
Open the folder on GitHubat commit d2f8d6a
Compare with similar skills
Skylos next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Skylos this skillduriantaco/skylos | 843 | — | ~581 | Automated safety check: Pass | Apache-2.0 | |
| CodeQL Security Scantrailofbits/skills | 7.4k | — | ~4.6k | Automated safety check: Notes | CC-BY-SA-4.0 | |
| Constant-Time Analysistrailofbits/skills | 7.4k | — | ~3.3k | Automated safety check: Notes | CC-BY-SA-4.0 | |
| Taint Instrumentation AssistantArabelaTso/Skills-4-SE | 253 | — | ~2.9k | Automated safety check: Pass | Apache-2.0 | |
| Codeqlgithub/awesome-copilot | 40k | 1 repos | ~3.4k | Automated safety check: Pass | MIT | |
| Security Reviewgithub/awesome-copilot | 40k | 1 repos | ~2.3k | Automated safety check: Notes | MIT |
Similar skills
- Official
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Constant-Time Analysis
trailofbits/skills
Compiles cryptographic code and inspects the assembly or bytecode for variable-time instructions, then triages which flagged operations actually touch secrets.
Taint Instrumentation Assistant
ArabelaTso/Skills-4-SE
Instruments code to track the flow of untrusted or sensitive data at runtime, enabling detection of injection vulnerabilities, data leaks, and privilege violations.
- Official
Codeql
github/awesome-copilot
Comprehensive guide for setting up and configuring CodeQL code scanning via GitHub Actions workflows and the CodeQL CLI.
- Official
Security Review
github/awesome-copilot
AI-powered codebase security scanner that reasons about code like a security researcher — tracing data flows, understanding component interactions, and catching vulnerabilities that pattern-matching…
Phy Regex Audit
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Static ReDoS (Regular Expression Denial of Service) vulnerability scanner and regex quality auditor for codebases.
More from duriantaco/skylos
Skylos Security
duriantaco/skylos
Investigate and harden Skylos security behavior. An agent skill from duriantaco/skylos.
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Categories
Questions about Skylos
What does Skylos do?
Run, interpret, or modify Skylos safely. An agent skill from duriantaco/skylos. Skylos is an agent skill from duriantaco/skylos. Run, interpret, or modify Skylos safely.
When should I use Skylos?
Skylos fits situations like: the user asks to scan code with Skylos; explain SKY- findings; triage dead-code false positives; audit security/secrets/SCA/LLM behavior.
How do I install Skylos in Claude Code?
Run `npx skills add duriantaco/skylos --skill skylos -a claude-code`. Or copy the skill folder (.agents/skills/skylos in duriantaco/skylos) into .claude/skills/skylos in your project. Claude Code loads it when a task matches its description.
How do I install Skylos in Codex?
Run `npx skills add duriantaco/skylos --skill skylos -a codex`. Or copy the skill folder (.agents/skills/skylos in duriantaco/skylos) into .agents/skills/skylos in your project. Codex loads it when a task matches its description.
Can I use Skylos in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add duriantaco/skylos --skill skylos -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/skylos, .gemini/skills/skylos, .github/skills/skylos and .opencode/skills/skylos in your project.
What does Skylos need to run?
Going by SKILL.md and its folder, Skylos needs the command-line tools its instructions call (git).
Does Skylos access the network?
SKILL.md contains no URLs. Its commands use git, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Skylos safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Skylos use?
Skylos is published under the Apache-2.0 licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Skylos use?
About 581 tokens (SKILL.md is roughly 2.3k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full. Its references folder adds about 3.7k tokens, read only when the agent opens those files.
What are the alternatives to Skylos?
Skills that share tags, products or a category with Skylos: CodeQL Security Scan (trailofbits/skills, 7.4k stars), Constant-Time Analysis (trailofbits/skills, 7.4k stars), Taint Instrumentation Assistant (ArabelaTso/Skills-4-SE, 253 stars) and Codeql (github/awesome-copilot, 40k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Skylos?
duriantaco (a GitHub user) maintains it in duriantaco/skylos, which has 843 GitHub stars. The repository holds 2 skills in this directory. The repository was last updated on October 8, 2026.
Source: duriantaco/skylos on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.