Aegis vs Gatekeeper

In-depth architectural comparison of the Aegis and Gatekeeper 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.

Which MCP Server Should You Choose?

Choose Aegis 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: YAML policy rules with approval gates, MCP stdio and HTTP transport proxy, Prompt-injection, PII, leak, and toxicity checks.

Explore Aegis Details

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).
• Primary tools included: Policy-based allow, deny, and approval decisions, Sensitive-boundary rule pack, USD, token, and call budgets.

Explore Gatekeeper Details

Feature & Specification Comparison

Specification	Aegis Acacian Security	Gatekeeper Security
Summary	Policy-based governance for AI agent tool calls. YAML policies, approval gates, risk assessment, and audit logging. Cross-platform: LangChain, OpenAI, Anthropic, MCP.	Run MCP tool calls through Runestone Gatekeeper — policy enforcement, human approval, audit.
Category & Scope	Security	Security

Tools & Capabilities Breakdown

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).

{
  "mcpServers": {
    "acacian-aegis": {
      "command": "uvx",
      "args": [
        "agent-aegis"
      ]
    }
  }
}

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

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