Aegis Security Skills

An independent open-source project, maintained by Drupad Sachania. Two products, one repository:

	Aegis	Themis
What	24 security skills, an installer and a read-only MCP server	A security-operations agent that plans, fans out to Aegis skills, checks every output and writes a version-stamped report
Calls a model?	Never. It is markdown and JSON	Uses your assistant (plugin) or your own key or a local model (standalone)
Package	aegis-skills	@aegis-skills/themis-plugin and @aegis-skills/themis

Status: Aegis 1.5.0 is on npm as aegis-skills, and the Claude Code plugin installs straight from this repository. The website is live. Themis is in development, local-first and not published as an app yet (run it from a checkout, see docs/themis); its two libraries, @aegis-skills/themis-core and @aegis-skills/themis-gateway, are on npm. The status table below says what is done and what is next.

---

Aegis

Defensive security skills in the open Agent Skills format. One source installs natively into coding assistants, is served over the Model Context Protocol, and flattens into a single-file prompt for any chat AI.

Skill library: 24 skills across 5 families

Family	Skills
Frameworks	mitre-attack · mitre-atlas · mitre-engage
Threat Intel	attack-surface-mapping · exposure-validation · threat-hunting · threat-intel-synthesis · threat-modeling
Response & Analysis	digital-forensics · malware-analysis · reverse-engineering · security-operations
Domain Defence	application-security · data-loss-prevention · deception-engineering · endpoint-security · identity-access-management · infrastructure-security · network-security · operational-technology
Governance & Risk	compliance · governance · risk-management · security-documentation

Each skill is a workflow of phases (methodology references) plus a live-threat-intel phase. Skill content is updated monthly. Browse them at aegis-skills.vercel.app.

Quick start

# Install the skills into your tool's native skills folder and register the MCP server
npx aegis-skills install --platform claude      # codex | gemini | cursor | vscode | antigravity | all
npx aegis-skills install --platform claude --project   # this project only

# Serve the whole library over MCP on stdio
npx aegis-skills mcp

Claude Code plugin: /plugin marketplace add drupadsachania/aegis-skills, then /plugin install aegis-skills@aegis-skills.

Needs Node.js 24 or later.

CLI commands

Command	What it does
aegis install [--platform <id>] [--project]	Copy the skills into each tool's native folder and register the MCP server (config files are backed up first). init is an alias
aegis uninstall [--platform <id>] [--project]	Remove only what Aegis installed; edited files are kept as .bak
aegis update	Re-sync every recorded install with the installed version
aegis list [--json]	Bundled skills and recorded installs
aegis mcp	Serve the skill library over MCP on stdio

Installed skills refresh automatically after an upgrade; set AEGIS_NO_AUTO_REFRESH=1 to turn that off.

Using a skill without installing

Every skill page on the website offers a single-file prompt (all phases flattened, stamped "Intel as of ") and a skill zip, and the whole library is available from the hosted MCP server. Build the prompts locally with npm run build:prompts (written to dist/prompts/, not committed).

MCP

Three read-only tools are offered: list_skills, get_skill, get_skill_phase. They serve public skill content only and never call a model.

{
  "mcpServers": {
    "aegis": { "command": "npx", "args": ["-y", "aegis-skills", "mcp"] }
  }
}

Hosted, with nothing to install (Streamable HTTP, no authentication): https://aegis-skills.vercel.app/api/mcp.

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Themis

Give Themis a task such as "validate exposure to CVE-2026-12345 on our VPN gateways". It runs a fixed seven-step workflow: validate, decompose, schedule, fan out to Aegis skills, guardrail, synthesise and audit. Deterministic steps are plain code in themis-core; reasoning steps are done by a model.

	Themis on your AI	Themis standalone
Model	Your assistant (Claude Code, Codex, Gemini CLI)	Your Anthropic, OpenAI or Gemini key, or a local model (Ollama, LM Studio)
Interface	Your assistant's chat, through the themis-mcp MCP server	A local web dashboard on 127.0.0.1
Approvals	Your client's MCP elicitation prompt, otherwise handed back to you	The dashboard's Approvals page
Install	An MCP config (a marketplace listing is planned)	npx @aegis-skills/themis dashboard

Governance is enforced in code, not by the model:

• External tools are classified read, write or execute. Every call, read included, becomes an approval request that only a human can approve; approved reads also run within a call budget.
• Access is default-deny: a server is reachable only by the skills in its allowedSkills.
• Secrets are redacted, tool output is size-capped and wrapped as untrusted, and every step, call and decision goes to a local audit log in ~/.themis.
• In plugin mode, tools you connect directly to your assistant bypass Themis and are not governed.

Read more: Themis docs and docs/themis.

---

Where things stand

	State	Next
Aegis skills, CLI, MCP	Built and tested on Linux, macOS and Windows (Node 24); 24 skills at version 1.5.0	Released: aegis-skills@1.5.0 is on npm. Next: marketplace and directory listings
Website and hosted MCP	Live at aegis-skills.vercel.app	Install commands are live
themis-core, themis-gateway	Built and tested; packaged and ready for npm	Released right after Aegis
Themis plugin and standalone app	Working from a checkout; no real-model run recorded in CI yet	Public beta: a model-backed end-to-end run, a clearer approval confirmation, diagnostics and issue templates
Marketplace listings	Aegis first, as a skills-only plugin	Themis follows once the beta settles

How this is maintained

• CI on every change. Tests run on Ubuntu, macOS and Windows with Node 24, plus lint, dependency and layout guards, a production site build, and install smoke tests of each package. Releases are published by a tag-driven workflow with provenance, not from a laptop.
• Skill content is refreshed monthly. Every flattened prompt is stamped with the date of its intel.
• Dependencies are pinned and watched. GitHub Actions are pinned to full commit SHAs and kept current by Dependabot.
• Defaults are conservative. Aegis never calls a model. Themis denies tool access by default, a human approves every external call, and prompts are redacted before they reach a model provider. Skills never make network or API calls themselves.

Found a bug or a skill that is out of date? Open an issue. For a vulnerability, use private reporting instead, as described in SECURITY.md.

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Links

• Website: https://aegis-skills.vercel.app
• Choose your path: https://aegis-skills.vercel.app/paths
• Docs: https://aegis-skills.vercel.app/docs
• Hosted MCP: https://aegis-skills.vercel.app/mcp
• Security: SECURITY.md
• License: LICENSE

---

Development

npm install
npm run dev                         # http://localhost:3000
npx jest                            # tests for every package
npm run build                       # production build
npm run check:deps                  # dependency guards
node scripts/check-layout.js        # layout guard
npm run lint:skills                 # skill format lint

The site lives in apps/web; npm run dev -w @aegis-skills/web starts it. Requires Node.js 24 or later.

Project structure

├── apps/web/            # the website: catalogue, docs hub, downloads, hosted MCP (no model calls)
├── packages/
│   ├── aegis/           # aegis-skills: 24 skills, installer CLI, MCP server
│   ├── themis-core/     # deterministic workflow, redaction, approvals, local store
│   ├── themis-gateway/  # governed MCP client for external tools
│   ├── themis-plugin/   # Themis on your AI (MCP server, orchestrator skill, agents)
│   └── themis-app/      # Themis standalone (CLI and local dashboard)
├── scripts/             # repo scripts: lint, guards, prompt builder
├── docs/{aegis,themis,web}/   # user documentation, published by the website
└── .claude-plugin/      # Claude Code marketplace manifest

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option (SPDX: Apache-2.0 OR MIT). See LICENSE and, for reporting vulnerabilities, SECURITY.md.