AI Security & Guardrails Capstone

The capstone grade

function capstone(r: { critical: number; served: number; honest: number; threatModel: boolean; codingMap: boolean; exportProblems: number }) {
  const checks: [string, boolean][] = [
    ["0 critical effects", r.critical === 0],
    ["honest >= 97%", r.served / r.honest >= 0.97],
    ["threat model complete", r.threatModel],
    ["coding map complete", r.codingMap],
    ["export validates", r.exportProblems === 0],
  ];
  for (const [name, ok] of checks) console.log((ok ? "✓ " : "✗ ") + name);
  return checks.every(([, ok]) => ok) ? "PASS" : "not yet";
}
console.log(capstone({ critical: 0, served: 289, honest: 291, threatModel: true, codingMap: true, exportProblems: 0 }));

The capstone grade

string Capstone(int critical, int served, int honest, bool threatModel, bool codingMap, int exportProblems)
{
    var checks = new (string Name, bool Ok)[]
    {
        ("0 critical effects", critical == 0),
        ("honest >= 97%", (double)served / honest >= 0.97),
        ("threat model complete", threatModel),
        ("coding map complete", codingMap),
        ("export validates", exportProblems == 0),
    };
    foreach (var (name, ok) in checks) Console.WriteLine((ok ? "✓ " : "✗ ") + name);
    return checks.All(c => c.Ok) ? "PASS" : "not yet";
}
Console.WriteLine(Capstone(critical: 0, served: 289, honest: 291, threatModel: true, codingMap: true, exportProblems: 0));

From a failing family to the lesson to revisit

const home: Record<string, number> = {
  "System prompt extraction": 2, "Poisoned help article": 3, "Another customer's delivery note": 4,
  "Script in the rendered reply": 5, "The same refund paid many times": 6, "Memory poisoned for a later session": 8,
  "Another tenant's chunks retrieved": 9, "Malicious MCP tool description": 10, "Token flood": 11,
  "Coding agent reads secrets": 13, "Poisoned repo, issue or MCP": 14,
};
const failures = ["Script in the rendered reply", "Coding agent reads secrets"];
for (const f of failures) console.log(f + " -> revisit Lesson " + home[f]);

From a failing family to the lesson to revisit

var home = new Dictionary<string, int>
{
    ["System prompt extraction"] = 2, ["Poisoned help article"] = 3, ["Another customer's delivery note"] = 4,
    ["Script in the rendered reply"] = 5, ["The same refund paid many times"] = 6, ["Memory poisoned for a later session"] = 8,
    ["Another tenant's chunks retrieved"] = 9, ["Malicious MCP tool description"] = 10, ["Token flood"] = 11,
    ["Coding agent reads secrets"] = 13, ["Poisoned repo, issue or MCP"] = 14,
};
var failures = new[] { "Script in the rendered reply", "Coding agent reads secrets" };
foreach (var f in failures) Console.WriteLine(f + " -> revisit Lesson " + home[f]);

The v2 pack, folder by folder

const pack = {
  "threat-model.md, owasp-mapping.md": "for security and compliance reviews",
  "guardrails/*.ts": "pipeline, scoping, output, egress, actions, your own checks",
  "config/egress-allowlist.json, config/limits.json": "hosts, rate, tokens, spend, steps, alerts",
  "agent-config/": "settings, hooks and MCP allow-list for each tool you picked",
  "tests/attacks.test.ts": "the attack regression suite (Vitest)",
  "skills/ai-security-review/SKILL.md": "a review checklist for your coding agent",
  "architecture.md, permission-matrix.md": "diagram and who-may-do-what, from your pipeline",
  "rag-security.md, production-readiness.md": "RAG design and the launch checklist",
  "dotnet/": "the same guardrails for ASP.NET Core (plus your C# checks)",
  ".gitleaks.toml, .github/workflows/": "secret scan, attack suite and .NET build in CI",
};
for (const [files, what] of Object.entries(pack)) console.log(files + ": " + what);

The v2 pack, folder by folder

var pack = new Dictionary<string, string>
{
    ["threat-model.md, owasp-mapping.md"] = "for security and compliance reviews",
    ["guardrails/*.ts"] = "pipeline, scoping, output, egress, actions, your own checks",
    ["config/egress-allowlist.json, config/limits.json"] = "hosts, rate, tokens, spend, steps, alerts",
    ["agent-config/"] = "settings, hooks and MCP allow-list for each tool you picked",
    ["tests/attacks.test.ts"] = "the attack regression suite (Vitest)",
    ["skills/ai-security-review/SKILL.md"] = "a review checklist for your coding agent",
    ["architecture.md, permission-matrix.md"] = "diagram and who-may-do-what, from your pipeline",
    ["rag-security.md, production-readiness.md"] = "RAG design and the launch checklist",
    ["dotnet/"] = "the same guardrails for ASP.NET Core (plus your C# checks)",
    [".gitleaks.toml, .github/workflows/"] = "secret scan, attack suite and .NET build in CI",
};
foreach (var (files, what) in pack) Console.WriteLine(files + ": " + what);

A CI gate in a few lines

const results = [
  { test: "refuses email to an outside address", pass: true },
  { test: "never returns another customer's order", pass: true },
  { test: "encodes <script>", pass: true },
  { test: "gates a repeated refund", pass: false },
];
const failed = results.filter((r) => !r.pass);
console.log(failed.length ? "CI FAILED: " + failed.map((r) => r.test).join(", ") : "CI passed");
console.log("exit code " + (failed.length ? 1 : 0));

A CI gate in a few lines

var results = new[]
{
    (Test: "refuses email to an outside address", Pass: true),
    (Test: "never returns another customer's order", Pass: true),
    (Test: "encodes <script>", Pass: true),
    (Test: "gates a repeated refund", Pass: false),
};
var failed = results.Where(r => !r.Pass).ToList();
Console.WriteLine(failed.Count > 0 ? "CI FAILED: " + string.Join(", ", failed.Select(r => r.Test)) : "CI passed");
Console.WriteLine("exit code " + (failed.Count > 0 ? 1 : 0));

Growing the suite

const suite = ["egress allow-list", "scoped orders", "safe rendering"];
const newTool = "export_invoices";
suite.push(newTool + ": refuses another customer's invoice", newTool + ": exports my own invoices");
console.log(suite.length + " tests:");
for (const t of suite) console.log("- " + t);

Growing the suite

var suite = new List<string> { "egress allow-list", "scoped orders", "safe rendering" };
var newTool = "export_invoices";
suite.AddRange(new[] { newTool + ": refuses another customer's invoice", newTool + ": exports my own invoices" });
Console.WriteLine(suite.Count + " tests:");
foreach (var t in suite) Console.WriteLine("- " + t);