Batch update course covers

Refresh the visual identity of every course in your classroom — without resetting privacy, tier, or amount. Uses classroom:updateCourse’s read-then-write to safely apply only the cover change.

This is exactly how the 17 covers in Cágala, Aprende, Repite were updated in one batch in May 2026.

When to use

The critical detail: don’t break privacy/tier

A naïve approach would be PUT /courses/{id} directly with just the cover fields. This silently resets privacy to 0 (Open) — your premium courses become public. See classroom docs → R-PUT-COURSE for the gory details.

The actor’s classroom:updateCourse handles this for you via read-then-write: it fetches each course’s current state first, merges your changes on top, and writes the full body. Use it.

The pipeline

[Plan JSON] ─→ for each course:
                  1. Render cover (HTML template → JPEG via Browserless / Playwright)
                  2. files:uploadImage (upload to Skool)
                  3. classroom:updateCourse (apply cover, preserve everything else)
                  4. Verify visually

The plan structure

Define a JSON array — one entry per course — with everything needed to render its cover:

[
  {
    "courseId": "32-char-hex-from-classroom-listCourses",
    "category": "ai-automatizaciones",
    "color": "#B366FF",
    "icon": "🤖",
    "label": "IA · AUTOMATIZACIONES",
    "title1": "AI AGENTS",
    "title2": "STARTER KIT",
    "subtitle": "Build your first AI agent in 2026 — WhatsApp, Make, n8n, local hardware.",
    "tag1": "WhatsApp · ventas",
    "tag2": "Dual-path Make/n8n",
    "tag3": "$0 to $200/mo",
    "tag4": "Llama local"
  },
  // ... one per course
]

(Field names match a typical synthwave-style template — adapt to your design.)

Render via HTML template

Most teams render covers from a single HTML template, substituting per-course values. Browserless / Playwright / Puppeteer takes the HTML and produces a JPEG.

async function renderCover(item, templateHtml) {
  let html = templateHtml;
  const subs = {
    __CAT__: item.color,
    __CAT_ICON__: item.icon,
    __CAT_LABEL__: item.label,
    __TITLE_LINE_1__: item.title1,
    __TITLE_LINE_2__: item.title2,
    __SUBTITLE__: item.subtitle,
    __TAG_1__: item.tag1,
    __TAG_2__: item.tag2,
    __TAG_3__: item.tag3,
    __TAG_4__: item.tag4,
  };
  for (const [k, v] of Object.entries(subs)) {
    html = html.split(k).join(v);
  }

  const r = await fetch(`https://browser.cristiantala.com/screenshot?token=${BROWSERLESS_TOKEN}`, {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
      html,
      options: { clip: { x: 0, y: 0, width: 1460, height: 752 }, type: 'jpeg', quality: 90 },
      viewport: { width: 1460, height: 752 },
    }),
  });
  return Buffer.from(await r.arrayBuffer());
}

(Replace browser.cristiantala.com with your Browserless instance, or use local Playwright.)

Upload + apply

async function callActor(input) {
  const r = await fetch(
    `https://api.apify.com/v2/acts/cristiantala~skool-all-in-one-api/run-sync-get-dataset-items?token=${APIFY_TOKEN}&build=latest&timeout=90`,
    { method: 'POST', headers: { 'Content-Type': 'application/json' }, body: JSON.stringify(input) },
  );
  return JSON.parse(await r.text())[0];
}

const auth = { cookies: COOKIES, groupSlug: GROUP_SLUG };

for (const item of plan) {
  // 1. Render
  const buf = await renderCover(item, templateHtml);
  console.log(`✓ rendered ${item.courseId}: ${buf.length} bytes`);

  // 2. Upload via actor
  const upload = await callActor({
    action: 'files:uploadImage', ...auth,
    params: { bufferBase64: buf.toString('base64') },
  });

  // 3. Apply — read-then-write preserves privacy/tier/amount
  const result = await callActor({
    action: 'classroom:updateCourse', ...auth,
    params: {
      courseId: item.courseId,
      coverImage: upload.coverImageUrl,
      coverImageFile: upload.coverImageFile,
    },
  });

  if (result.success === false) {
    console.error(`❌ ${item.courseId}: ${result.errorCode}`);
    continue;
  }
  console.log(`✓ updated ${item.courseId}`);

  // Pace yourself — Skool's writes/min cap
  await new Promise(r => setTimeout(r, 1500));
}

Verification

After the batch:

  1. Spot-check 2-3 courses visually in /classroom — open them, confirm the new cover loads (force browser cache reset with Cmd+Shift+R)
  2. Verify privacy/tier preserved: call classroom:listCourses and assert each course’s metadata.privacy and metadata.min_tier still match the pre-batch state. If any reset to 0, the actor’s read-then-write didn’t run as expected — open an issue.

Cache notes

Skool’s CDN caches covers for ~5 minutes. If you re-screenshot the classroom right after the batch, the old covers may still appear. Wait 5 min, hard refresh the browser, then verify.

Common gotchas

Don’t pass desc if you only want to change the cover

classroom:updateCourse passes-through any field you provide. If you accidentally pass an empty desc: "", you’ll wipe the description. The read-then-write only fills in fields you omit — fields you explicitly pass override.

Skool downscales covers

Even though you upload 1460×752, Skool serves a smaller version on the classroom grid. The full-size cover only shows on hover or in the course header. Render at 1460×752 anyway — sharper downscale.

Don’t put links in the cover JPEG — they’re not clickable in Skool’s UI. Use the cover for visual identity; use the course desc for the value prop.

See also

More in Recipes