What is the key difference between Aegis and Shield?

Aegis belongs to the Security category with local stdio execution, while Shield belongs to the Security category with local stdio execution.

How do I install Aegis or Shield 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 Aegis and Shield free or paid?

Aegis operates under a Free / Open Source model (No auth required). Shield operates under a Free / Open Source model (No auth required).

Which MCP server has more tools and community activity?

Aegis lists 6 tools with 0 views and 0 GitHub stars. Shield lists 6 tools with 4 views and 11 GitHub stars.

Can I use both Aegis and Shield 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

Aegis vs Shield

In-depth architectural comparison of the Aegis and Shield 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

Aegis

Security · Local stdio

Quality: 52/100 (Good) | Auth: No auth required

Shield

Security · Local stdio

Quality: 63/100 (Good) | Auth: No auth required

Verdict Summary: Choose Aegis if you need specialized Security tools running via a local process. Choose Shield 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 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: aegis_evaluate_proposal, aegis_quick_risk_check, aegis_health.

Explore Aegis Details

Choose Shield 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: Pre-execution MCP call guardrails, TOFU tool-catalog pinning, Tool description and result scanning.

Explore Shield Details

Feature & Specification Comparison

Specification	Aegis Security	Shield AperionAI Security
Summary	Six-gate governance for AI agents: PROCEED/PAUSE/HALT decisions with hash-chained audit trails.	Local guardrail proxy for AI coding agents. Wraps any MCP server (stdio or Streamable HTTP) and blocks destructive tool calls — DROP TABLE, rm -rf, force-push — before they execute. MCP supply-chain protection: TOFU tool-catalog pinning against rug pulls, plus tool-description and tool-result scanning for tool poisoning and prompt injection. 51 starter rules, approval gates, audit logging. Single binary, Apache-2.0.
Category & Scope

Tools & Capabilities Breakdown

Aegis Tools (6)

aegis_evaluate_proposal

Evaluate an engineering proposal through the AEGIS gate checks.

aegis_quick_risk_check

Quick risk threshold check without a full Bayesian evaluation.

aegis_health

Check AEGIS API health (service status, version, components).

aegis_list_decisions

List recent governance decisions for the authenticated customer.

aegis_get_decision

Fetch a specific governance decision by ID, with full gate detail.

aegis_get_usage

Get the authenticated customer's evaluation usage report.

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).

Aegis Configuration

mcpServers (Claude Desktop / Cursor)

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

Shield Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "aperionai-shield": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-postgres"
      ]
    }
  }
}

Frequently Asked Questions

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

More alternatives to Aegis More alternatives to Shield Security category hub