GatewayStack

Stop shipping AI integrations with shared API keys and no audit trail

Reference implementation · Live demo in ChatGPT · gatewaystack.com

The problem

AI apps have three actors — user, LLM, and backend — but no shared identity layer. The user authenticates with the LLM, then the LLM calls your backend with a shared API key. Your backend can't tell who the request is for.

      Without GatewayStack              With GatewayStack

        USER (Alice)                      USER (Alice)
           │                                 │
           │ ✓ Authenticated                 │ ✓ Authenticated
           ▼                                 ▼
         LLM                               LLM
           │                                 │
           │ ❌ Shared API key               │ ✓ RS256 JWT
           ▼                                 ▼
       BACKEND                         GATEWAYSTACK
           │                          (Verify & Inject)
           │ ❓ Who is this?                 │
           │ ❓ What can they do?            │ ✓ X-User-Id, scopes
                                             ▼
                                         BACKEND
                                             │
                                             │ ✅ Knows: Alice, scopes
                                             │ ✅ Enforces policy

GatewayStack sits between the LLM and your backend. It verifies OAuth tokens, enforces per-user policies, and injects verified identity — so every AI request is attributable, authorized, and auditable. Full explanation →

Quickstart

npm install @gatewaystack/identifiabl express

import express from "express";
import { identifiabl } from "@gatewaystack/identifiabl";

const app = express();

app.use(identifiabl({
  issuer: process.env.OAUTH_ISSUER!,
  audience: process.env.OAUTH_AUDIENCE!,
}));

app.get("/api/me", (req, res) => {
  res.json({ user: req.user.sub, scopes: req.user.scope });
});

app.listen(8080);

Every request now requires a valid RS256 JWT. req.user contains the verified identity.

Modules

All six governance layers are live on npm. Each has a -core package (framework-agnostic) and an Express middleware wrapper. Detailed breakdown →

Module	npm	What it does
@gatewaystack/identifiabl		RS256 JWT verification, identity normalization
@gatewaystack/transformabl		PII detection, redaction, safety classification
@gatewaystack/validatabl		Deny-by-default policy engine, scope/permission enforcement
@gatewaystack/limitabl		Rate limits, budget tracking, agent guard
@gatewaystack/proxyabl		Auth mode routing, SSRF protection, identity-aware proxy
@gatewaystack/explicabl		Structured audit logging, health endpoints

Full stack example

Wire all six layers together. Each is optional — use only what you need.

npm install @gatewaystack/identifiabl @gatewaystack/transformabl @gatewaystack/validatabl \
  @gatewaystack/limitabl @gatewaystack/proxyabl @gatewaystack/explicabl @gatewaystack/request-context express

import express from "express";
import { runWithGatewayContext } from "@gatewaystack/request-context";
import { identifiabl } from "@gatewaystack/identifiabl";
import { transformabl } from "@gatewaystack/transformabl";
import { validatabl } from "@gatewaystack/validatabl";
import { limitabl } from "@gatewaystack/limitabl";
import { createProxyablRouter, configFromEnv } from "@gatewaystack/proxyabl";
import { createConsoleLogger, explicablLoggingMiddleware } from "@gatewaystack/explicabl";

const app = express();
app.use(express.json());

// 1. Establish request context for downstream layers
app.use((req, _res, next) => {
  runWithGatewayContext(
    { request: { method: req.method, path: req.path } },
    () => next()
  );
});

// 2. Log every request
app.use(explicablLoggingMiddleware(createConsoleLogger()));

// 3. Require verified RS256 token
app.use(identifiabl({
  issuer: process.env.OAUTH_ISSUER!,
  audience: process.env.OAUTH_AUDIENCE!,
}));

// 4. Detect PII and classify content safety
app.use("/tools", transformabl({ blockThreshold: 80 }));

// 5. Enforce authorization policies
app.use("/tools", validatabl({
  requiredPermissions: ["tool:read"],
}));

// 6. Apply rate limits and budget caps
app.use("/tools", limitabl({
  rateLimit: { windowMs: 60_000, maxRequests: 100 },
  budget: { maxSpend: 500, periodMs: 86_400_000 },
}));

// 7. Route /tools to your tool/model backends
app.use("/tools", createProxyablRouter(configFromEnv(process.env)));

app.listen(8080, () => {
  console.log("GatewayStack running on :8080");
});

Or clone and run the reference gateway directly:

git clone https://github.com/davidcrowe/GatewayStack
cd GatewayStack
npm install
npm run dev   # gateway on :8080, admin UI on :5173

GatewayStack vs traditional API gateways

Repository layout

Testing

npm test

135 tests across 17 test files covering all five core packages.

Prerequisites

• Node.js 20+
• npm 10+ (or pnpm 9)
• An OIDC provider issuing RS256 access tokens (Auth0, Okta, Entra ID, Keycloak, etc.)

Docs

• The Three-Party Problem
• Package Breakdown
• Examples
• Demos
• Environment & Health Endpoints
• Deployment
• Troubleshooting
• Production Checklist

Contributing

• Run the tests: npm test
• Read CONTRIBUTING.md
• Report issues on GitHub Issues

For the enterprise and leadership pitch, see gatewaystack.com.