What is the key difference between Gatekeeper and Assay?

Gatekeeper belongs to the Security category with local stdio execution, while Assay belongs to the Security category with local stdio execution.

How do I install Gatekeeper or Assay in Claude Desktop or Cursor?

Copy the mcpServers JSON configuration snippet provided on this page into your claude_desktop_config.json or ~/.cursor/mcp.json file and restart your AI client.

Are Gatekeeper and Assay free or paid?

Gatekeeper operates under a Free / Open Source model (No auth required). Assay operates under a Free / Open Source model (No auth required).

Which MCP server has more tools and community activity?

Gatekeeper lists 0 tools with 1 views and 0 GitHub stars. Assay lists 6 tools with 1 views and 10 GitHub stars.

Can I use both Gatekeeper and Assay together in the same MCP host?

Yes! MCP hosts like Claude Desktop, Cursor, Windsurf, Cline, and VS Code support configuring multiple servers under the mcpServers object simultaneously.

Side-by-Side Model Context Protocol Comparison

Gatekeeper vs Assay

In-depth architectural comparison of the Gatekeeper and Assay MCP servers. Compare execution transports, security boundaries, tool capabilities, quality scores, and ready-to-paste client installation snippets for Claude, Cursor, Windsurf, and VS Code.

At a Glance & Executive Verdict

Gatekeeper

Security · Local stdio

Quality: 43/100 (Fair) | Auth: No auth required

Assay

Security · Local stdio

Quality: 47/100 (Fair) | Auth: No auth required

Verdict Summary: Choose Gatekeeper if you need specialized Security tools running via a local process. Choose Assay if your workspace requires Security integration with local subprocess execution. Both servers can be configured concurrently in your client's mcpServers manifest.

Which MCP Server Should You Choose?

Choose Gatekeeper when:

You need dedicated capabilities in the Security domain.
You prefer local stdio subprocess transport architecture.
Your security boundary fits: No auth required (Free / Open Source).

Explore Gatekeeper Details

Choose Assay when:

You need dedicated capabilities in the Security domain.
You prefer local stdio subprocess transport architecture.
Your security boundary fits: No auth required (Free / Open Source).
Primary tools included: Deterministic, fail-closed policy enforcement for MCP tool calls, Offline-verifiable, tamper-evident evidence bundles of decisions and observations, Kernel-level IPv4/TCP egress enforcement via eBPF/LSM and Landlock on Linux.

Explore Assay Details

Feature & Specification Comparison

Specification	Gatekeeper Security	Assay Rul1an Security
Summary	Run MCP tool calls through Runestone Gatekeeper — policy enforcement, human approval, audit.	Policy-as-code gate for MCP. A fail-closed proxy that denies risky tool calls before they run, produces offline-verifiable evidence bundles of what executed, and enforces IPv4/TCP egress in-kernel via eBPF/LSM and Landlock on Linux. Deterministic and offline-first.
Category & Scope	Security

Tools & Capabilities Breakdown

Gatekeeper Tools (0)

No explicit tool names declared in metadata yet. Check project README on main listing page.

Assay Tools (6)

Deterministic, fail-closed policy enforcement for MCP tool calls

Offline-verifiable, tamper-evident evidence bundles of decisions and observations

Kernel-level IPv4/TCP egress enforcement via eBPF/LSM and Landlock on Linux

Trust basis classification with explicit claim provenance

CI-native operation with no hosted backend or API keys required

Ready-to-Paste Client Configurations

Paste either (or both) of these JSON server blocks into your client config file (e.g. claude_desktop_config.json or ~/.cursor/mcp.json).

Gatekeeper Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "gatekeeper": {
      "command": "npx",
      "args": [
        "-y",
        "@runestone-labs/gatekeeper-mcp"
      ]
    }
  }
}

Assay Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "rul1an-assay": {
      "command": "npx",
      "args": [
        "-y",
        "rul1an-assay"
      ]
    }
  }
}

Frequently Asked Questions

Gatekeeper is categorized under Security and uses a local stdio subprocess. In contrast, Assay belongs to Security using local stdio subprocess. Select Gatekeeper when you need capabilities focused on security and Assay when you require tools for security.

More alternatives to Gatekeeper More alternatives to Assay Security category hub