diff --git a/package-lock.json b/package-lock.json
index 7a0d8f9..099663a 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -11,6 +11,38 @@
         "packages/*"
       ]
     },
+    "../../../shieldx": {
+      "name": "@shieldx/core",
+      "version": "0.5.0",
+      "license": "Apache-2.0",
+      "dependencies": {
+        "pg": "^8.13.0",
+        "pgvector": "^0.2.0",
+        "pino": "^9.6.0",
+        "zod": "^3.24.0"
+      },
+      "devDependencies": {
+        "@types/node": "^22.0.0",
+        "@types/pg": "^8.11.0",
+        "@vitest/coverage-v8": "^3.0.0",
+        "eslint": "^9.0.0",
+        "tsup": "^8.3.0",
+        "tsx": "^4.19.0",
+        "typescript": "^5.7.0",
+        "vitest": "^3.0.0"
+      },
+      "engines": {
+        "node": ">=20.0.0"
+      },
+      "peerDependencies": {
+        "next": ">=15.0.0"
+      },
+      "peerDependenciesMeta": {
+        "next": {
+          "optional": true
+        }
+      }
+    },
     "node_modules/@esbuild/aix-ppc64": {
       "version": "0.27.7",
       "resolved": "https://registry.npmjs.org/@esbuild/aix-ppc64/-/aix-ppc64-0.27.7.tgz",
@@ -935,6 +967,10 @@
         "win32"
       ]
     },
+    "node_modules/@shieldx/core": {
+      "resolved": "../../../shieldx",
+      "link": true
+    },
     "node_modules/@types/estree": {
       "version": "1.0.8",
       "resolved": "https://registry.npmjs.org/@types/estree/-/estree-1.0.8.tgz",
@@ -3425,6 +3461,7 @@
         "@fastify/cors": "^9.0.1",
         "@fastify/helmet": "^11.1.1",
         "@fastify/rate-limit": "^9.1.0",
+        "@shieldx/core": "file:../../../../../shieldx",
         "ajv": "^8.17.1",
         "fastify": "^4.28.1",
         "franc": "^6.2.0",
diff --git a/packages/gateway/package.json b/packages/gateway/package.json
index 9642941..7008a6b 100644
--- a/packages/gateway/package.json
+++ b/packages/gateway/package.json
@@ -12,6 +12,7 @@
     "@fastify/cors": "^9.0.1",
     "@fastify/helmet": "^11.1.1",
     "@fastify/rate-limit": "^9.1.0",
+    "@shieldx/core": "file:../../../../../shieldx",
     "ajv": "^8.17.1",
     "fastify": "^4.28.1",
     "franc": "^6.2.0",
diff --git a/packages/gateway/src/routes/completion.ts b/packages/gateway/src/routes/completion.ts
index 9563e91..3c7e739 100644
--- a/packages/gateway/src/routes/completion.ts
+++ b/packages/gateway/src/routes/completion.ts
@@ -17,6 +17,32 @@ import {
   validationFailuresTotal,
 } from '../observability/metrics.js';
 import { logger } from '../observability/logger.js';
+import { ShieldX } from '@shieldx/core';
+
+// Singleton ShieldX instance — initialized once, sub-millisecond scans
+// Disable Ollama-dependent scanners (sentinel, constitutional, embedding, attention)
+// to keep gateway scans fast and dependency-free
+const shieldx = new ShieldX({
+  scanners: {
+    rules: true,           // 547+ rules, 50+ languages
+    sentinel: false,       // Requires Ollama
+    constitutional: false, // Requires Ollama
+    embedding: false,      // Requires Ollama
+    embeddingAnomaly: false,
+    entropy: true,         // Zero-cost entropy analysis
+    yara: false,           // Requires YARA binary
+    attention: false,      // Requires Ollama
+    canary: false,         // Not needed in gateway context
+    indirect: true,        // RAG/tool injection detection
+    selfConsciousness: false,
+    crossModel: false,
+    behavioral: true,      // Session profiling
+    unicode: true,         // Homoglyph/script detection
+    tokenizer: true,       // I.g.n.o.r.e-style attacks
+    compressedPayload: true,
+  },
+  logging: { level: 'warn', structured: true, incidentLog: false },
+} as any);  // DeepPartial config — merges with defaults
 
 const CompletionRequestSchema = z.object({
   caller: z.string().min(1).max(100),
@@ -38,43 +64,37 @@ type CompletionRequest = z.infer<typeof CompletionRequestSchema>;
 
 const SKIP_SHIELDX_CALLERS = new Set(['internal', 'shieldx']);
 
-async function runShieldXScan(input: string, caller: string): Promise<{ passed: boolean; reason?: string }> {
-  const GATEWAY_URL = `http://localhost:${process.env['PORT'] ?? '3100'}`;
+async function runShieldXScan(
+  input: string,
+  caller: string,
+): Promise<{ passed: boolean; reason?: string; threatLevel?: string; phase?: string; latencyMs?: number }> {
   try {
-    const response = await fetch(`${GATEWAY_URL}/v1/completion`, {
-      method: 'POST',
-      headers: { 'Content-Type': 'application/json', 'X-Caller-ID': 'internal' },
-      body: JSON.stringify({
-        caller: 'internal',
-        task_type: 'shieldx_threat_classification',
-        input,
-        options: { return_validation_details: false },
-      }),
-      signal: AbortSignal.timeout(8000),
-    });
+    const result = await shieldx.scanInput(input);
 
-    if (!response.ok) return { passed: true }; // Fail open if ShieldX is down
+    if (result.detected) {
+      logger.warn({
+        caller,
+        threatLevel: result.threatLevel,
+        phase: result.killChainPhase,
+        action: result.action,
+        latencyMs: result.latencyMs,
+        ensemble: result.ensemble,
+        atlasMapping: result.atlasMapping?.techniqueIds?.slice(0, 5),
+        scannerCount: result.scanResults.length,
+      }, 'ShieldX threat detected — input blocked');
 
-    const result = await response.json() as { output?: string; status?: string };
-    if (result.status !== 'approved' || !result.output) return { passed: true };
-
-    type ShieldResult = { threat_detected: boolean; threat_type?: string; confidence?: number };
-    let parsed: ShieldResult;
-    try {
-      parsed = JSON.parse(result.output) as ShieldResult;
-    } catch {
-      return { passed: true };
+      return {
+        passed: false,
+        reason: `Prompt injection detected: ${result.killChainPhase} (${result.threatLevel})`,
+        threatLevel: result.threatLevel,
+        phase: result.killChainPhase,
+        latencyMs: result.latencyMs,
+      };
     }
 
-    if (parsed.threat_detected && (parsed.confidence ?? 0) > 0.8) {
-      logger.warn({ caller, threat_type: parsed.threat_type }, 'ShieldX threat detected');
-      return { passed: false, reason: `Threat detected: ${parsed.threat_type ?? 'unknown'}` };
-    }
-
-    return { passed: true };
+    return { passed: true, latencyMs: result.latencyMs };
   } catch (err) {
-    // ShieldX unavailable — fail open (log but continue)
-    logger.warn({ err, caller }, 'ShieldX scan failed, continuing without scan');
+    logger.error({ err, caller }, 'ShieldX scan error — failing open');
     return { passed: true };
   }
 }
@@ -102,7 +122,7 @@ export async function completionRoute(fastify: FastifyInstance): Promise<void> {
       const { caller, input, language, context, options } = body;
       const returnValidationDetails = options?.return_validation_details ?? false;
 
-      // Stage 2: ShieldX scan
+      // Stage 2: ShieldX scan (real library, 547+ rules, sub-millisecond)
       if (!SKIP_SHIELDX_CALLERS.has(caller)) {
         const shieldResult = await runShieldXScan(input, caller);
         if (!shieldResult.passed) {
@@ -111,6 +131,9 @@ export async function completionRoute(fastify: FastifyInstance): Promise<void> {
             statusCode: 400,
             error: 'Rejected',
             message: shieldResult.reason ?? 'Input rejected by security scan',
+            threat_level: shieldResult.threatLevel,
+            kill_chain_phase: shieldResult.phase,
+            shieldx_latency_ms: shieldResult.latencyMs,
           });
         }
       }