setTimeout(ok, 500)); // let a few frames draw
return { t: Date.now(), text: String(text), jpg: await p.screenshot({ type: 'jpeg', quality: 80 }) };
})()]);
cache.set(place + ':' + look, view);
const mb = (await page.metrics()).JSHeapUsedSize / 1048576; // memory cap (JS heap): recycle
if (mb > MAX_MB) await stop();
return view;
} catch (e) { await stop(); throw e; } // a hung page is recycled
finally { clearTimeout(timer); }
});
queue = job.catch(() => {});
return job;
}
function limited(ip) { // N new renders per minute per IP
const now = Date.now(), a = (hits.get(ip) || []).filter(t => now - t < 60e3);
a.push(now); hits.set(ip, a); return a.length > PER_MIN;
}
const esc = s => String(s).replace(/[&<>"]/g, c => ({ '&': '&', '<': '<', '>': '>', '"': '"' })[c]);
const app = express();
app.get(['/see', '/see.txt', '/see.jpg'], async (req, res) => {
const place = String(req.query.go || 'start'), look = String(req.query.look || 'ahead');
if (!Object.hasOwn(PLACES, place) || !LOOKS.includes(look))
return res.status(400).type('text').send('unknown; try ?go=' + Object.keys(PLACES).join('|') + '&look=' + LOOKS.join('|'));
let view = cache.get(place + ':' + look);
if (!view || Date.now() - view.t > CACHE_MS) {
if (limited(req.ip)) return res.status(429).set('Retry-After', '30').type('text').send('slow down, try again in 30 s');
const fresh = render(place, look);
const quick = new Promise(ok => setTimeout(ok, 8000)); // never hang: answer within 8 s
view = await Promise.race([fresh, quick]).catch(() => null) || view; // else the last (stale) view
}
if (!view) return res.status(503).set('Retry-After', '15').type('text').send('warming up, refresh in 15 s');
const links = Object.keys(PLACES).map(p => [p, 'go=' + p]).concat(LOOKS.map(l => [l, 'go=' + place + '&look=' + l]));
if (req.path === '/see.jpg') return res.type('jpeg').send(view.jpg);
if (req.path === '/see.txt') return res.type('text').send(view.text + '\n\nPicture: /see.jpg?go=' + place +
'&look=' + look + '\nActions:\n' + links.map(([n, q]) => ' ' + n + ': /see.txt?' + q).join('\n') + '\n');
res.type('html').send('<!doctype html><meta charset="utf-8"><title>View: ' + esc(place) + '</title>' +
'<img src="/see.jpg?go=' + place + '&look=' + look + '" style="max-width:100%" alt="' + esc(view.text) + '">' +
'<p>' + esc(view.text) + '</p><ul>' + links.map(([n, q]) => '<li><a href="/see?' + q.replace('&', '&') + '">' + (q.includes('look') ? 'Look ' : 'Go to ') + n + '</a></li>').join('') + '</ul>');
});
app.listen(8080, '127.0.0.1', () => console.log('AI view on http://127.0.0.1:8080/see'));
Install with npm i express puppeteer-core and point CHROME at a Chromium on the server. It listens on 127.0.0.1:8080; let your web server forward /see, /see.txt and /see.jpg to it.
Test it with curl
Test it the way an AI uses it: no JavaScript, just requests.
# 1. the text view (what a text-only AI reads)
curl -s "http://127.0.0.1:8080/see.txt?go=castle&look=left"
# 2. the picture (what an image-reading AI looks at)
curl -s -o castle.jpg -w "%{http_code} %{content_type} %{size_download}\n" \
"http://127.0.0.1:8080/see.jpg?go=castle"
# 3. the whitelist holds: a URL or unknown place gets 400
curl -s -w " %{http_code}\n" "http://127.0.0.1:8080/see?go=http://example.com"
# 4. the cache works: a repeat view should take well under 1 s
curl -s -o /dev/null -w "%{time_total}\n" "http://127.0.0.1:8080/see?go=castle"
# 5. the links work: list every href on the HTML view
curl -s "http://127.0.0.1:8080/see?go=castle" | grep -o 'href="[^"]*"'
Checklist
- The page loads and makes sense with JavaScript turned off (try
curl).
- Every view has a picture, a text readout and action links.
- Every action is a plain
<a href> link with a short query, like ?go=castle&look=left.
- Unknown places, URLs and paths get a 400. The browser cannot leave your site.
- One browser, one page, one render at a time (a queue).
- A cache of 30 to 60 seconds per place, and the last good view is kept.
- A per-IP rate limit that answers 429 with Retry-After.
- A render timeout, and a "warming up" answer instead of a hung request.
- The browser closes when idle and restarts on demand.
- A