diff --git a/ApiCore-Frontend/Dockerfile b/ApiCore-Frontend/Dockerfile
index a1058ff..4ec9a5c 100644
--- a/ApiCore-Frontend/Dockerfile
+++ b/ApiCore-Frontend/Dockerfile
@@ -11,6 +11,8 @@ RUN npx next typegen
 # Unit-Tests gruen sind.
 RUN npm run lint && npx tsc --noEmit && npm test
 RUN npm run build
+# Bundle-Budget (Spec Beute-3D §9.9): schlaegt fehl, wenn der 3D-Chunk > 320 kB gzip ist.
+RUN npm run check:3d-budget
 
 FROM node:22-alpine@sha256:0a7108bf6c7bf5de370ffb1a3ed6be93d405b43ff159f681a8d18c0e2bc2e402 AS runtime
 ENV NODE_ENV=production
diff --git a/ApiCore-Frontend/package.json b/ApiCore-Frontend/package.json
index 73e755c..67f9075 100644
--- a/ApiCore-Frontend/package.json
+++ b/ApiCore-Frontend/package.json
@@ -9,7 +9,8 @@
     "lint": "eslint",
     "typecheck": "next typegen && tsc --noEmit",
     "test": "vitest run",
-    "test:watch": "vitest"
+    "test:watch": "vitest",
+    "check:3d-budget": "node scripts/check-3d-budget.mjs"
   },
   "dependencies": {
     "@base-ui/react": "^1.7.0",
diff --git a/ApiCore-Frontend/scripts/check-3d-budget.mjs b/ApiCore-Frontend/scripts/check-3d-budget.mjs
new file mode 100644
index 0000000..271ba61
--- /dev/null
+++ b/ApiCore-Frontend/scripts/check-3d-budget.mjs
@@ -0,0 +1,63 @@
+// Bundle-Budget fuer den lazy geladenen Beute-3D-Chunk.
+// Spec: docs/superpowers/specs/2026-10-15-beute-3d-design.md (§9.9 / L3).
+// Laeuft nach `next build`; Exit 1, wenn der three.js-Chunk das Budget
+// ueberschreitet oder gar kein three.js-Chunk gefunden wird.
+import { readdirSync, readFileSync } from "node:fs";
+import path from "node:path";
+import { fileURLToPath } from "node:url";
+import { gzipSync } from "node:zlib";
+
+// Spec §9.9: hoechstens 320 kB gzip fuer den 3D-Chunk (1 kB = 1000 Byte).
+export const BUDGET_BYTES = 320_000;
+
+// Stabile Marker, die three.js auch minifiziert im Chunk behaelt (String-
+// Literale): der Renderer-Name und die globale Mehrfach-Import-Markierung.
+const THREE_MARKERS = ["WebGLRenderer", "__THREE__"];
+
+export function isThreeChunk(source) {
+  return THREE_MARKERS.every((marker) => source.includes(marker));
+}
+
+/**
+ * Misst den groessten three.js-Chunk (gzip level 9) unter chunksDir.
+ * @returns {{ ok: boolean, file: string | null, gzipBytes: number, budget: number, message: string }}
+ */
+export function checkBudget(chunksDir, budget = BUDGET_BYTES) {
+  let largest = null;
+  for (const name of readdirSync(chunksDir)) {
+    if (!name.endsWith(".js")) continue;
+    const source = readFileSync(path.join(chunksDir, name));
+    if (!isThreeChunk(source.toString("latin1"))) continue;
+    const gzipBytes = gzipSync(source, { level: 9 }).length;
+    if (!largest || gzipBytes > largest.gzipBytes) largest = { file: name, gzipBytes };
+  }
+  if (!largest) {
+    return {
+      ok: false,
+      file: null,
+      gzipBytes: 0,
+      budget,
+      message: `Kein three.js-Chunk in ${chunksDir} gefunden (Marker: ${THREE_MARKERS.join(", ")}). Check kaputt oder Bundle umgebaut?`,
+    };
+  }
+  const ok = largest.gzipBytes <= budget;
+  return {
+    ok,
+    ...largest,
+    budget,
+    message: `3D-Chunk ${largest.file}: ${largest.gzipBytes} Byte gzip, Budget ${budget} Byte${ok ? "" : " UEBERSCHRITTEN"}`,
+  };
+}
+
+if (process.argv[1] && path.resolve(process.argv[1]) === fileURLToPath(import.meta.url)) {
+  const chunksDir = path.resolve(process.cwd(), ".next/static/chunks");
+  let result;
+  try {
+    result = checkBudget(chunksDir);
+  } catch (error) {
+    console.error(`check-3d-budget: ${chunksDir} nicht lesbar (zuerst next build?): ${error.message}`);
+    process.exit(1);
+  }
+  (result.ok ? console.log : console.error)(result.message);
+  process.exit(result.ok ? 0 : 1);
+}
diff --git a/ApiCore-Frontend/scripts/check-3d-budget.test.ts b/ApiCore-Frontend/scripts/check-3d-budget.test.ts
new file mode 100644
index 0000000..d7033ff
--- /dev/null
+++ b/ApiCore-Frontend/scripts/check-3d-budget.test.ts
@@ -0,0 +1,51 @@
+// @vitest-environment node
+import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
+import { randomBytes } from "node:crypto";
+import { tmpdir } from "node:os";
+import path from "node:path";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { BUDGET_BYTES, checkBudget } from "./check-3d-budget.mjs";
+
+const threeChunk = (filler: string) => `/*WebGLRenderer*/window.__THREE__="186";${filler}`;
+// Hex of random bytes is barely compressible by gzip (about 50 %).
+const noise = (bytes: number) => randomBytes(bytes).toString("hex");
+
+describe("check-3d-budget", () => {
+  let dir: string;
+  beforeEach(() => {
+    dir = mkdtempSync(path.join(tmpdir(), "budget-"));
+  });
+  afterEach(() => rmSync(dir, { recursive: true, force: true }));
+
+  it("passes when the three.js chunk is under budget", () => {
+    writeFileSync(path.join(dir, "a.js"), threeChunk("x".repeat(1000)));
+    writeFileSync(path.join(dir, "other.js"), "console.log(1)");
+    const result = checkBudget(dir);
+    expect(result.ok).toBe(true);
+    expect(result.file).toBe("a.js");
+  });
+
+  it("fails when the three.js chunk is over budget", () => {
+    writeFileSync(path.join(dir, "big.js"), threeChunk(noise(1000)));
+    const result = checkBudget(dir, 100);
+    expect(result.ok).toBe(false);
+    expect(result.gzipBytes).toBeGreaterThan(100);
+  });
+
+  it("measures the largest of several three.js chunks", () => {
+    writeFileSync(path.join(dir, "small.js"), threeChunk("x"));
+    writeFileSync(path.join(dir, "large.js"), threeChunk(noise(2000)));
+    expect(checkBudget(dir).file).toBe("large.js");
+  });
+
+  it("fails when no three.js chunk exists", () => {
+    writeFileSync(path.join(dir, "app.js"), "export const a = 1; // WebGLRenderer only");
+    const result = checkBudget(dir);
+    expect(result.ok).toBe(false);
+    expect(result.file).toBeNull();
+  });
+
+  it("uses the spec budget of 320 kB by default", () => {
+    expect(BUDGET_BYTES).toBe(320_000);
+  });
+});