diff --git a/api/verify.js b/api/verify.js
index a1fe9c4..e4ce6f2 100644
--- a/api/verify.js
+++ b/api/verify.js
@@ -3,6 +3,15 @@
 const { verifyReceipt } = require('../lib/verifyReceipt');
 const MAX_JSON_BODY_BYTES = 1024 * 1024; // 1 MiB
 
+
+function resolveCorsOrigin(originHeader) {
+  if (!originHeader || typeof originHeader !== 'string') return null;
+  if (originHeader === 'https://www.commandlayer.org' || originHeader === 'https://commandlayer.org') return originHeader;
+  if (originHeader.startsWith('chrome-extension://')) return originHeader;
+  return null;
+}
+
+
 function isOversizedJsonBody(req) {
   const contentLengthHeader = req?.headers?.['content-length'] || req?.headers?.['Content-Length'];
   const parsedContentLength = Number.parseInt(String(contentLengthHeader || ''), 10);
@@ -22,8 +31,20 @@ module.exports = async function handler(req, res) {
   res.setHeader('Content-Type', 'application/json; charset=utf-8');
   res.setHeader('Cache-Control', 'no-store');
 
+  const allowedOrigin = resolveCorsOrigin(req?.headers?.origin || req?.headers?.Origin);
+  if (allowedOrigin) {
+    res.setHeader('Access-Control-Allow-Origin', allowedOrigin);
+    res.setHeader('Vary', 'Origin');
+  }
+  res.setHeader('Access-Control-Allow-Methods', 'POST,OPTIONS');
+  res.setHeader('Access-Control-Allow-Headers', 'Content-Type');
+
+  if (req.method === 'OPTIONS') {
+    return res.status(204).end();
+  }
+
   if (req.method !== 'POST') {
-    res.setHeader('Allow', 'POST');
+    res.setHeader('Allow', 'POST,OPTIONS');
     return res.status(405).json({ ok: false, status: 'INVALID', reason: 'Method not allowed. Use POST.' });
   }
 
diff --git a/docs/extension/chrome-receipt-inspector.md b/docs/extension/chrome-receipt-inspector.md
new file mode 100644
index 0000000..53189dd
--- /dev/null
+++ b/docs/extension/chrome-receipt-inspector.md
@@ -0,0 +1,34 @@
+# Chrome Receipt Inspector (Developer Preview Foundation)
+
+Status: planned / developer preview. Not published to Chrome Web Store.
+
+## Goal
+Provide a browser-side helper that can detect potential CommandLayer receipt IDs on pages and help users verify receipts using the public verifier API.
+
+## Detection
+The extension content script scans page text for IDs matching:
+
+- `clrcpt_[a-f0-9]{32}`
+
+## Verification path
+- Verify endpoint: `https://www.commandlayer.org/api/verify`
+- Method: `POST` with JSON body containing a receipt object.
+
+## CORS requirement
+`/api/verify` must allow:
+- Origins:
+  - `https://www.commandlayer.org`
+  - `https://commandlayer.org`
+  - `chrome-extension://*`
+- Methods: `POST`, `OPTIONS`
+- Headers: `Content-Type`
+
+## Receipt lookup options
+1. Preferred (when implemented): fetch by ID via:
+   - `/receipts/{receiptId}.json`
+2. Current fallback: popup requires users to paste full receipt JSON.
+
+## Security and scope
+- No private keys in extension code.
+- No admin or payment endpoints.
+- No claims about production store release until launch readiness.
diff --git a/extension/chrome-receipt-inspector/README.md b/extension/chrome-receipt-inspector/README.md
new file mode 100644
index 0000000..ac8b636
--- /dev/null
+++ b/extension/chrome-receipt-inspector/README.md
@@ -0,0 +1,7 @@
+# CommandLayer Receipt Inspector (Developer Preview)
+
+This is a developer-preview scaffold only.
+
+- Detects `clrcpt_[a-f0-9]{32}` in page text via content script.
+- Supports paste-and-verify flow against `https://www.commandlayer.org/api/verify`.
+- Receipt ID lookup via `/receipts/{id}.json` is pending.
diff --git a/extension/chrome-receipt-inspector/background.js b/extension/chrome-receipt-inspector/background.js
new file mode 100644
index 0000000..e5b27de
--- /dev/null
+++ b/extension/chrome-receipt-inspector/background.js
@@ -0,0 +1 @@
+chrome.runtime.onInstalled.addListener(()=>{console.log('CommandLayer Receipt Inspector developer preview installed');});
diff --git a/extension/chrome-receipt-inspector/content.css b/extension/chrome-receipt-inspector/content.css
new file mode 100644
index 0000000..916ad23
--- /dev/null
+++ b/extension/chrome-receipt-inspector/content.css
@@ -0,0 +1 @@
+body{min-width:320px;font-family:Arial,sans-serif}textarea{width:100%;min-height:120px}pre{white-space:pre-wrap;word-break:break-word}
diff --git a/extension/chrome-receipt-inspector/content.js b/extension/chrome-receipt-inspector/content.js
new file mode 100644
index 0000000..cd7fef7
--- /dev/null
+++ b/extension/chrome-receipt-inspector/content.js
@@ -0,0 +1,4 @@
+const re=/clrcpt_[a-f0-9]{32}/g;
+const txt=document.body?.innerText||'';
+const matches=[...new Set(txt.match(re)||[])];
+if(matches.length){console.debug('CommandLayer receipt IDs detected',matches.slice(0,20));}
diff --git a/extension/chrome-receipt-inspector/manifest.json b/extension/chrome-receipt-inspector/manifest.json
new file mode 100644
index 0000000..9494e58
--- /dev/null
+++ b/extension/chrome-receipt-inspector/manifest.json
@@ -0,0 +1,24 @@
+{
+  "manifest_version": 3,
+  "name": "CommandLayer Receipt Inspector (Developer Preview)",
+  "version": "0.0.1",
+  "description": "Developer preview foundation for scanning potential CommandLayer receipt IDs and verifying pasted receipts.",
+  "permissions": ["storage"],
+  "host_permissions": [
+    "https://www.commandlayer.org/*",
+    "https://commandlayer.org/*"
+  ],
+  "action": {
+    "default_popup": "popup.html"
+  },
+  "background": {
+    "service_worker": "background.js"
+  },
+  "content_scripts": [
+    {
+      "matches": ["http://*/*", "https://*/*"],
+      "js": ["content.js"],
+      "css": ["content.css"]
+    }
+  ]
+}
diff --git a/extension/chrome-receipt-inspector/popup.html b/extension/chrome-receipt-inspector/popup.html
new file mode 100644
index 0000000..ccab275
--- /dev/null
+++ b/extension/chrome-receipt-inspector/popup.html
@@ -0,0 +1 @@
+<!doctype html><html><head><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><link rel="stylesheet" href="content.css"></head><body><main><h3>Receipt Inspector</h3><p>Developer preview. Paste full receipt JSON.</p><textarea id="receipt" placeholder='{"signer":"..."}'></textarea><button id="verify">Verify</button><pre id="out"></pre></main><script src="popup.js"></script></body></html>
diff --git a/extension/chrome-receipt-inspector/popup.js b/extension/chrome-receipt-inspector/popup.js
new file mode 100644
index 0000000..db4bee3
--- /dev/null
+++ b/extension/chrome-receipt-inspector/popup.js
@@ -0,0 +1,6 @@
+const out=document.getElementById('out');
+document.getElementById('verify').addEventListener('click',async()=>{
+  let payload;try{payload=JSON.parse(document.getElementById('receipt').value);}catch(e){out.textContent='Invalid JSON';return;}
+  const r=await fetch('https://www.commandlayer.org/api/verify',{method:'POST',headers:{'Content-Type':'application/json'},body:JSON.stringify(payload)});
+  out.textContent=JSON.stringify(await r.json(),null,2);
+});
diff --git a/public/playground.html b/public/playground.html
new file mode 100644
index 0000000..9093e96
--- /dev/null
+++ b/public/playground.html
@@ -0,0 +1,51 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+<meta charset="UTF-8" />
+<meta name="viewport" content="width=device-width, initial-scale=1.0" />
+<title>CommandLayer Playground</title>
+<link rel="icon" href="/favicon.ico" />
+<link rel="stylesheet" href="/css/site.css" />
+<style>
+.play-wrap{padding:64px 0 88px;background:linear-gradient(180deg,#F9FAFF 0%,#F3F6FF 100%)}
+.card{background:#fff;border:1px solid var(--border);border-radius:16px;padding:18px;box-shadow:0 1px 2px rgba(15,23,42,.04)}
+.grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}.row{margin-bottom:12px}
+textarea,select,input{width:100%;border:1px solid rgba(15,23,42,.18);border-radius:10px;padding:10px;font:14px/1.5 Inter,sans-serif}
+textarea{min-height:140px}.btns{display:flex;gap:8px;flex-wrap:wrap}.mono{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;font-size:12px;white-space:pre-wrap;word-break:break-word}
+@media(max-width:960px){.grid{grid-template-columns:1fr}}
+</style>
+</head>
+<body>
+<nav><div class="container nav-inner"><a href="/" class="brand"><img src="/commandlayer-logo.png" alt="CommandLayer" /><span>CommandLayer</span></a><ul class="nav-links"><li><a href="/">Home</a></li><li><a href="/proof.html">Live Proof</a></li><li><a href="/verify.html">Verifier</a></li><li><a href="/docs.html">Docs</a></li></ul></div></nav>
+<main class="play-wrap"><div class="container">
+<h1 class="section-h2">Playground</h1>
+<p class="section-p">Try a CommandLayer-style flow: choose a verb, submit text, and verify a sample receipt.</p>
+<div class="grid" style="margin-top:16px;">
+<section class="card">
+<div class="row"><label>Verb</label><select id="verb"><option>verify</option><option>attest</option><option>authorize</option><option>approve</option></select></div>
+<div class="row"><label>Input text</label><textarea id="input" placeholder="Paste text"></textarea></div>
+<div class="btns"><button id="runBtn" class="btn btn-primary" type="button">Run</button><button id="sampleBtn" type="button">Use sample receipt</button></div>
+<p id="runtimeNote" style="margin-top:10px;color:#334155;">Live runtime unavailable. Use sample receipt.</p>
+</section>
+<section class="card">
+<h3>Receipt JSON</h3><pre id="receipt" class="mono">No receipt yet.</pre>
+<div class="btns" style="margin-top:10px"><a class="btn btn-secondary" id="openVerify" href="/verify.html">Open verifier</a></div>
+</section>
+</div></div></main>
+<script>
+const sampleEndpoint='/receipts/demo-valid-receipt.json';
+const receiptEl=document.getElementById('receipt');
+const openVerify=document.getElementById('openVerify');
+let latestReceipt=null;
+async function loadSample(){
+  const r=await fetch(sampleEndpoint,{cache:'no-store'});
+  if(!r.ok) throw new Error('Sample receipt unavailable');
+  latestReceipt=await r.json();
+  receiptEl.textContent=JSON.stringify(latestReceipt,null,2);
+  openVerify.href='/verify.html#manual-verifier';
+}
+document.getElementById('sampleBtn').addEventListener('click',async()=>{try{await loadSample()}catch(e){receiptEl.textContent=e.message;}});
+document.getElementById('runBtn').addEventListener('click',async()=>{receiptEl.textContent='Live runtime unavailable. Use sample receipt.';});
+</script>
+</body>
+</html>
diff --git a/tests/api-verify.test.js b/tests/api-verify.test.js
index 78a014f..5b75314 100644
--- a/tests/api-verify.test.js
+++ b/tests/api-verify.test.js
@@ -109,7 +109,7 @@ test('GET /api/verify => 405', async () => {
   await handler(req, res);
 
   assert.equal(res.statusCode, 405);
-  assert.equal(res.headers.allow, 'POST');
+  assert.equal(res.headers.allow, 'POST,OPTIONS');
   assert.equal(res.body.ok, false);
 });