# stig-mcp

A local MCP (Model Context Protocol) server that lets an AI assistant, such as GitHub
Copilot in VS Code or Claude Code, answer security questions from published guidance instead
of from memory. Name a MITRE ATT&CK® technique or threat actor and the system you care
about, and the answer gives you:

- the NIST SP 800-53 security controls that mitigate it;
- the DISA STIG configuration rules that implement those controls on that system, most
  severe first, with DISA's check and fix text on request;
- ATT&CK's own mitigations, and which of its detections work with the logs you collect.

It does not scan or connect to your systems. Its answers come from a knowledge base, a local
database of about 6 MB built from those public sources, which you install once. The
[user guide](https://github.com/jeneric/STIG-MCP/blob/main/docs/user-guide.md#summary) explains what it
does and shows [three ways to use it](https://github.com/jeneric/STIG-MCP/blob/main/docs/user-guide.md#three-ways-to-use-it): as a security controls
assessor, a system owner, or a SOC analyst.

<!-- mcp-name: io.github.jeneric/stig-mcp -->

## Prerequisite

stig-mcp is published on [PyPI](https://pypi.org/project/stig-mcp/) and runs through `uvx`,
which comes with [uv](https://docs.astral.sh/uv/).
[Install uv](https://docs.astral.sh/uv/getting-started/installation/), then check that
`uvx --version` runs in a new terminal. Restart VS Code or Claude Code after installing uv
so it sees the new `PATH`.

## Quick start

### VS Code (GitHub Copilot)

1. Click this badge. VS Code opens and offers to install stig-mcp; choose **Install**.

   [![Install in VS Code](https://img.shields.io/badge/VS_Code-Install_stig--mcp-0098FF?logo=visualstudiocode&logoColor=white)](https://vscode.dev/redirect/mcp/install?name=stig-mcp&config=%7B%22type%22%3A%22stdio%22%2C%22command%22%3A%22uvx%22%2C%22args%22%3A%5B%22stig-mcp%22%5D%2C%22env%22%3A%7B%22UV_SYSTEM_CERTS%22%3A%22true%22%2C%22UV_NATIVE_TLS%22%3A%22true%22%7D%7D)

2. Open Copilot Chat and set the mode dropdown to **Agent**. MCP tools are not available in
   Ask or Edit mode.
3. Ask: `Install the stig-mcp knowledge base.` This is a one-time download of about 6 MB.
   Allow the tool when VS Code asks.

If that doesn't work, see [troubleshooting](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#troubleshooting) or
[setting up VS Code by hand](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#vs-code-github-copilot).

### Claude Code

1. Inside a Claude Code session (2.1.275 or later), run:

       /plugin install stig-mcp --marketplace jeneric/STIG-MCP

2. Ask: `Install the stig-mcp knowledge base.` This is a one-time download of about 6 MB.
   Allow the tool when Claude Code asks.

If that doesn't work, see [troubleshooting](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#troubleshooting) or
[setting up Claude Code by hand](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#claude-code).

## Example prompts

With the knowledge base installed, try:

1. System owner: `What DISA STIG steps mitigate T1078 on Windows 11?`
2. Security controls assessor: `Which ATT&CK techniques does APT29 use?`
3. Anyone, to find the right STIG: `Which STIG benchmarks apply to RHEL 9?`
4. SOC analyst: `What can I detect of APT29 on Windows Server 2022 with Security and Sysmon logs?`

[More example prompts](https://github.com/jeneric/STIG-MCP/blob/main/docs/user-guide.md#more-example-prompts) are in the user guide, with
[how to get more out of it](https://github.com/jeneric/STIG-MCP/blob/main/docs/user-guide.md#how-do-i-get-more-out-of-it) and
[how to make sure the agent answers from the server](https://github.com/jeneric/STIG-MCP/blob/main/docs/user-guide.md#getting-the-model-to-use-the-server).

## Other MCP clients

Use this only if you are not using VS Code or Claude Code. Any client that launches a local
(stdio) MCP server works with this configuration, shown in the common `mcpServers` shape:

```json
{
  "mcpServers": {
    "stig-mcp": {
      "command": "uvx",
      "args": ["stig-mcp"],
      "env": { "UV_SYSTEM_CERTS": "true", "UV_NATIVE_TLS": "true" }
    }
  }
}
```

The two environment variables let uv download stig-mcp
[behind a TLS-inspecting proxy](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#behind-a-tls-inspecting-proxy). They are
harmless on most other hosts; that section names the one exception. Then ask the agent to install the stig-mcp knowledge base, as in the
quick start.

[docs/install.md](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md) has the details:

- manual [VS Code](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#vs-code-github-copilot) and [Claude Code](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#claude-code) setup
- [running from a source checkout](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#running-from-a-source-checkout)
- [installing the knowledge base](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#installing-the-knowledge-base) without an agent or without network access
- [where the data lives](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#where-the-data-lives)
- [troubleshooting](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md#troubleshooting)

## What this server fetches

- The MCP server contacts nothing unless `check_sources` or `install_knowledge_base` is
  called. Then it sends HTTPS GET requests to `api.github.com` (this repository's release
  listing) and `github.com` (`/jeneric/STIG-MCP/releases/download/...`), which redirects to
  `release-assets.githubusercontent.com` or `objects.githubusercontent.com`. Any other URL, a
  redirect included, is refused. Nothing is uploaded, and there is no telemetry.
  `install_knowledge_base` given a file path and its SHA-256 requests nothing at all.
- `stig-mcp-install-kb` contacts the same hosts, and nothing at all with `--file`.
- `stig-mcp-fetch`, used only to build the knowledge base yourself, downloads from
  `raw.githubusercontent.com` and `api.github.com` (MITRE ATT&CK, the CTID mapping, the NIST
  800-53 catalog) and from `dl.dod.cyber.mil` (DISA).

[PRIVACY.md](https://github.com/jeneric/STIG-MCP/blob/main/PRIVACY.md) states what each of these requests sends and what is stored locally.

## Documentation

- [docs/install.md](https://github.com/jeneric/STIG-MCP/blob/main/docs/install.md): installation details for every client, where the data lives, and troubleshooting.
- [docs/user-guide.md](https://github.com/jeneric/STIG-MCP/blob/main/docs/user-guide.md): for a person talking to an LLM that has this server wired in.
- [docs/operations.md](https://github.com/jeneric/STIG-MCP/blob/main/docs/operations.md): for whoever installs, builds and maintains the knowledge base.
- [SECURITY.md](https://github.com/jeneric/STIG-MCP/blob/main/SECURITY.md): reporting a vulnerability, and what is in scope.
- [CONTRIBUTING.md](https://github.com/jeneric/STIG-MCP/blob/main/CONTRIBUTING.md): working from a source checkout, running the tests, and the project's conventions.
- [RELEASING.md](https://github.com/jeneric/STIG-MCP/blob/main/RELEASING.md): for the maintainer, publishing the package to PyPI and the MCP Registry.
- [PRIVACY.md](https://github.com/jeneric/STIG-MCP/blob/main/PRIVACY.md): what the server and the fetch tool contact, and what is stored locally.

## Third-party content

The knowledge base aggregates MITRE ATT&CK, CTID mapping, DISA STIG, DISA CCI
list, and NIST OSCAL content. See [NOTICE](https://github.com/jeneric/STIG-MCP/blob/main/NOTICE) for attribution and licensing obligations
and [licenses/apache-2.0.txt](https://github.com/jeneric/STIG-MCP/blob/main/licenses/apache-2.0.txt) for the Apache 2.0
license text that notice requires.

## Development

Developed with the assistance of Claude Code (Anthropic). All changes were reviewed and
tested by the maintainer.