Declarative URL-allowlist firewall for agent tool calls via @mukundakatta/agentguard-mcp — check, batch-check, validate policies

{
  "server": "@mukundakatta/agentguard-mcp",
  "version": "0.1.0",
  "transport": "stdio",
  "tools": ["check_url", "check_urls_batch", "validate_policy"],
  "calls": [
    {
      "tool": "check_url",
      "args": {
        "url": "https://api.openai.com/v1/chat",
        "policy": {
          "allow": ["api.openai.com", "*.github.com"]
        }
      },
      "result": {
        "allowed": true,
        "reason": "matched_allowlist"
      },
      "ms": 134
    },
    {
      "tool": "check_url",
      "args": {
        "url": "https://evil.com/steal",
        "policy": {
          "allow": ["api.openai.com"]
        }
      },
      "result": {
        "allowed": false,
        "reason": "not_in_allowlist",
        "detail": "evil.com"
      },
      "ms": 1
    },
    {
      "tool": "check_url",
      "args": {
        "url": "https://internal.example.com/secret",
        "policy": {
          "allow": ["*.example.com"],
          "deny": ["internal.example.com"]
        }
      },
      "result": {
        "allowed": false,
        "reason": "denylist_match"
      },
      "ms": 2
    },
    {
      "tool": "check_url",
      "args": {
        "url": "https://api.service.com/data",
        "method": "DELETE",
        "policy": {
          "allow": ["api.service.com"],
          "methods": ["GET", "POST"]
        }
      },
      "result": {
        "allowed": false,
        "reason": "method_blocked",
        "detail": "DELETE"
      },
      "ms": 1
    },
    {
      "tool": "check_urls_batch",
      "args": {
        "urls": ["https://api.openai.com/v1/chat", "https://evil.com/phish", "https://cdn.example.com/asset.js", "https://internal.example.com/admin"],
        "policy": {
          "allow": ["*.example.com"],
          "deny": ["internal.example.com"]
        }
      },
      "result": {
        "summary": {
          "total": 4,
          "allowed_count": 1,
          "denied_count": 3
        }
      },
      "ms": 3
    },
    {
      "tool": "validate_policy",
      "args": {
        "policy": {
          "allow": ["*"]
        }
      },
      "result": {
        "valid": false,
        "issues": ["pattern * matches every host"]
      },
      "ms": 4
    },
    {
      "tool": "validate_policy",
      "args": {
        "policy": {
          "allow": ["https://api.openai.com/v1"]
        }
      },
      "result": {
        "valid": false,
        "issues": ["scheme detected", "path detected"]
      },
      "ms": 2
    },
    {
      "tool": "check_url",
      "args": {
        "url": "http://localhost:3000",
        "policy": {
          "allow": ["localhost"]
        }
      },
      "result": {
        "allowed": true,
        "reason": "matched_allowlist"
      },
      "ms": 5
    }
  ],
  "summary": {
    "total": 16,
    "success": 16,
    "p50_ms": 2
  }
}