diff --git a/tools/loop/dist/cli.js b/tools/loop/dist/cli.js
index 8ba15aa4..7be4bc02 100755
--- a/tools/loop/dist/cli.js
+++ b/tools/loop/dist/cli.js
@@ -139,6 +139,17 @@ async function main() {
         return;
     }
     if (cmd === '--interactive' || cmd === '-i') {
+        // Mirrors cmdWizard()'s TTY gate below: runInteractiveWizard() drives
+        // readline.question(), which resolves immediately with '' when stdin
+        // isn't a TTY (a CI step, piped input, `< /dev/null`) instead of
+        // waiting for a human. Without this guard, loop --interactive in a
+        // non-interactive context silently ran the wizard with every prompt
+        // answered blank and scaffolded files nobody asked for.
+        if (!process.stdin.isTTY) {
+            printNonInteractiveHelp();
+            process.exitCode = 0;
+            return;
+        }
         const plan = await runInteractiveWizard();
         process.exitCode = await executePlan(plan);
         return;
diff --git a/tools/loop/src/cli.ts b/tools/loop/src/cli.ts
index 441d3068..a9d5fca4 100644
--- a/tools/loop/src/cli.ts
+++ b/tools/loop/src/cli.ts
@@ -153,6 +153,17 @@ async function main(): Promise<void> {
     return;
   }
   if (cmd === '--interactive' || cmd === '-i') {
+    // Mirrors cmdWizard()'s TTY gate below: runInteractiveWizard() drives
+    // readline.question(), which resolves immediately with '' when stdin
+    // isn't a TTY (a CI step, piped input, `< /dev/null`) instead of
+    // waiting for a human. Without this guard, loop --interactive in a
+    // non-interactive context silently ran the wizard with every prompt
+    // answered blank and scaffolded files nobody asked for.
+    if (!process.stdin.isTTY) {
+      printNonInteractiveHelp();
+      process.exitCode = 0;
+      return;
+    }
     const plan = await runInteractiveWizard();
     process.exitCode = await executePlan(plan);
     return;
diff --git a/tools/loop/test/cli.test.mjs b/tools/loop/test/cli.test.mjs
index 0b4f523a..2f39cef8 100644
--- a/tools/loop/test/cli.test.mjs
+++ b/tools/loop/test/cli.test.mjs
@@ -2,7 +2,7 @@ import { test } from 'node:test';
 import assert from 'node:assert/strict';
 import path from 'node:path';
 import { fileURLToPath } from 'node:url';
-import { execFile } from 'node:child_process';
+import { execFile, execFileSync } from 'node:child_process';
 import { promisify } from 'node:util';
 import { access } from 'node:fs/promises';
 
@@ -75,6 +75,34 @@ test('loop status --json includes recentRuns array', async () => {
   assert.equal(typeof report.nextHint, 'string');
 });
 
+test('loop --interactive with closed (non-TTY) stdin prints help instead of scaffolding', async () => {
+  const { mkdtemp, rm, readdir } = await import('node:fs/promises');
+  const { tmpdir } = await import('node:os');
+  const dir = await mkdtemp(path.join(tmpdir(), 'loop-interactive-nontty-'));
+  try {
+    // execFileSync's input: '' pipes an empty stdin and closes it, the same
+    // shape as `loop --interactive < /dev/null` in CI -- readline's
+    // question() resolves immediately with '' instead of waiting on a
+    // human. Before the TTY guard, this ran the wizard's default plan
+    // (loop init . --pattern daily-triage --tool grok) against cwd.
+    const stdout = execFileSync(process.execPath, [CLI, '--interactive'], {
+      cwd: dir,
+      input: '',
+      encoding: 'utf8',
+      maxBuffer: 10 * 1024 * 1024,
+    });
+    assert.match(stdout, /Week-one path/);
+    // "→ loop init" only appears when executePlan() actually runs init;
+    // printNonInteractiveHelp()'s own copy-paste suggestions don't use the arrow.
+    assert.doesNotMatch(stdout, /→ loop init/);
+
+    const entries = await readdir(dir);
+    assert.deepEqual(entries, [], 'must not scaffold files from a non-TTY --interactive run');
+  } finally {
+    await rm(dir, { recursive: true, force: true });
+  }
+});
+
 test('loop doctor on empty temp dir is blocked', async () => {
   const { mkdtemp, rm } = await import('node:fs/promises');
   const { tmpdir } = await import('node:os');