Aliner-hello Academic PDF Downloader
Download PDFs from academic publishers that employ anti-bot / cookie-wall protections (Springer, BMC, Nature, and others).
Why this exists
Academic publishers, especially Springer/BMC, use an IDP (identity provider) redirect chain to verify browsers support cookies:
/article/doi → 303 redirect → idp.springer.com/authorize?response_type=cookie
→ redirect back with idp_session cookie → article page
Standard tools fail for two reasons:
- curl / Python requests — go through system proxy (127.0.0.1:7897 or similar), which may be blocked or unreliable for academic sites.
- Node.js
fetch()— bypasses the proxy but does NOT persist cookies across redirects, so the IDP cookie check fails witherror=cookies_not_supported.
The bundled script solves both: Node.js native http/https module (no proxy)
- manual cookie jar across redirects.
How to use
1. Run the bundled script directly
node "<skill-dir>/scripts/download.js" <doi|url|pmid> [output-path]
Examples:
# By DOI
node ".../download.js" "10.1186/s13075-026-03828-4" "/path/to/paper.pdf"
# By URL
node ".../download.js" "https://link.springer.com/article/10.1186/s13075-026-03828-4"
# By PMID (auto-resolves via PubMed)
node ".../download.js" "42143348"
# Custom output dir via env
PDF_OUTPUT_DIR="$HOME/Desktop" node ".../download.js" "10.1186/..."
2. If the script fails for a new publisher
First check <skill-dir>/scripts/download.js — the publisher resolution
logic is in the PUBLISHERS array. Each publisher has:
test(url)— returns true if this handler appliesgetPdfUrl(articleUrl, cookies, ua)— returns the PDF download URL
For a new publisher, add a handler. The existing springer handler and
generic fallback cover most cases. If the generic fallback returns a
non-PDF response, inspect the article page HTML to find the real download
URL pattern.
3. What the script does
1. Resolve input (DOI → doi.org, PMID → pubmed, URL → as-is)
2. Visit article page with cookie jar (handles IDP redirects)
3. Find PDF download URL from page HTML
4. Download PDF with auth cookies + Referer
5. Save to disk, report size & page count
Common failure modes
| Symptom | Cause | Fix |
|---|---|---|
| 404 on PDF URL | Wrong URL pattern for this publisher | Add publisher handler in PUBLISHERS |
error=cookies_not_supported in URL |
Script not following redirects with cookies | Ensure using bundled script, not fetch/curl |
| Empty file / HTML saved | PDF behind additional auth step | Check res.headers.content-type, add cookies from extra redirect |
| Timeout | Large PDF, slow connection | Increase timeout in script (default 120s for PDF) |
Adding a new publisher
Open <skill-dir>/scripts/download.js and add an entry to the PUBLISHERS array:
{
name: 'elsevier',
test: (url) => /sciencedirect\.com|elsevier\.com/.test(url.hostname),
async getPdfUrl(articleUrl, cookies, ua) {
const res = await fetchWithCookies(articleUrl, {
headers: { 'User-Agent': ua, Accept: 'text/html', Cookie: cookies },
});
const html = res.body.toString('utf-8');
// Find PDF link in page — adjust selector per publisher
const match = html.match(/href="([^"]+\.pdf[^"]*)"/i);
return match ? new URL(match[1], articleUrl).href : null;
},
},