diff --git a/scripts/test_approved_plan_continuity_gate.mjs b/scripts/test_approved_plan_continuity_gate.mjs
new file mode 100644
index 0000000..e3775d7
--- /dev/null
+++ b/scripts/test_approved_plan_continuity_gate.mjs
@@ -0,0 +1,114 @@
+#!/usr/bin/env node
+import { mkdirSync, mkdtempSync, rmSync, writeFileSync } from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import { spawnSync } from 'node:child_process';
+import { fileURLToPath } from 'node:url';
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
+const gateScript = path.join(__dirname, 'approved_plan_continuity_gate.mjs');
+
+function createFixture(files = {}) {
+  const root = mkdtempSync(path.join(os.tmpdir(), 'approved-plan-continuity-'));
+
+  for (const [relativePath, content] of Object.entries(files)) {
+    const filePath = path.join(root, relativePath);
+    mkdirSync(path.dirname(filePath), { recursive: true });
+    writeFileSync(filePath, typeof content === 'string' ? content : `${JSON.stringify(content, null, 2)}\n`);
+  }
+
+  return {
+    root,
+    path(...segments) {
+      return path.join(root, ...segments);
+    },
+    cleanup() {
+      rmSync(root, { recursive: true, force: true });
+    },
+  };
+}
+
+function runGate({ args = [], stdin = null } = {}) {
+  const result = spawnSync(process.execPath, [gateScript, ...args], {
+    input: stdin,
+    encoding: 'utf8',
+  });
+
+  let json = null;
+  if (result.stdout && result.stdout.trim()) {
+    try {
+      json = JSON.parse(result.stdout);
+    } catch {
+      json = null;
+    }
+  }
+
+  return {
+    status: result.status,
+    stdout: result.stdout,
+    stderr: result.stderr,
+    json,
+  };
+}
+
+const tests = [
+  {
+    name: 'skeleton: gate script responds with placeholder envelope when given fixture input',
+    run() {
+      const fixture = createFixture({
+        'input.json': {
+          planId: 'plan-skeleton',
+          currentTask: 'task-5',
+        },
+      });
+
+      try {
+        const result = runGate({
+          args: ['--compact', '--input', fixture.path('input.json')],
+        });
+
+        if (result.status !== 0 && result.status !== null) {
+          throw new Error(`expected controlled execution, got status=${result.status}\n${result.stderr || result.stdout}`);
+        }
+
+        if (!result.json || typeof result.json !== 'object') {
+          throw new Error(`expected JSON output\nstdout=${result.stdout}`);
+        }
+
+        if (result.json.gate !== 'approved_plan_continuity') {
+          throw new Error(`expected gate=approved_plan_continuity, got ${JSON.stringify(result.json.gate)}`);
+        }
+      } finally {
+        fixture.cleanup();
+      }
+    },
+  },
+];
+
+const results = [];
+let failed = false;
+
+for (const test of tests) {
+  try {
+    test.run();
+    results.push({ test: test.name, ok: true });
+  } catch (error) {
+    failed = true;
+    results.push({
+      test: test.name,
+      ok: false,
+      error: error instanceof Error ? error.message : String(error),
+    });
+  }
+}
+
+const summary = {
+  total: tests.length,
+  passed: results.filter((entry) => entry.ok).length,
+  failed: results.filter((entry) => !entry.ok).length,
+};
+
+process.stdout.write(`${JSON.stringify({ summary, results }, null, 2)}\n`);
+
+if (failed) process.exit(1);