Search academic sources for papers on a topic, retrieve publication details, and find available PDFs. The skill guides source selection, combines results across services, and removes duplicates using DOIs, unique identifiers assigned to papers.
This skill should be used when the user asks to "search for academic papers", "find working papers on SSRN", "look up a DOI", "download paper PDF", "check open access availability", "search NBER papers", "find arXiv preprints", or "search CrossRef". Provides unified search, metadata retrieval, and PDF download across arXiv, NBER, SSRN, CrossRef, OpenAlex, Unpaywall, and Semantic Scholar. Covers economics, finance, social science, CS/AI, and all academic disciplines.
Run score Not tested
See how to installReview the instructions the agent will receive before you install.
A unified toolkit for discovering, retrieving metadata, and downloading academic papers across all major sources. The right API depends on the task — this skill routes to the best source.
What is needed?
│
├─ SEARCH for papers on a topic
│ ├─ arXiv preprints (CS/AI/Physics/Econ) ──→ arXiv API
│ ├─ NBER working papers (economics) ───────→ NBER API
│ ├─ SSRN working papers (social science) ──→ OpenAlex (primary) + CrossRef prefix:10.2139
│ ├─ Published journal articles ────────────→ CrossRef API or OpenAlex
│ └─ Broad multi-source search ─────────────→ OpenAlex API
│
├─ GET METADATA for a known paper
│ ├─ Have DOI ──→ CrossRef (structured) or OpenAlex (richer)
│ ├─ Have arXiv ID ──→ arXiv API
│ ├─ Have NBER number ──→ NBER API
│ └─ Have SSRN abstract ID ──→ OpenAlex DOI lookup (DOI = 10.2139/ssrn.{id})
│
├─ FIND/DOWNLOAD PDF
│ ├─ Have DOI ──→ Unpaywall API (check OA) → OpenAlex (alt PDF links)
│ ├─ arXiv paper ──→ Direct: https://arxiv.org/pdf/{id}
│ ├─ NBER paper ──→ Direct: https://www.nber.org/system/files/working_papers/w{n}/w{n}.pdf
│ └─ SSRN paper ──→ Unpaywall (~30%) or institutional repos (EconStor, IZA)
│
└─ IMPORT TO ZOTERO
└─ Always use zotero_add_by_doi (best metadata + auto PDF via Unpaywall cascade)
Free, no API key needed. Covers 250M+ works including SSRN, NBER, arXiv, all journals.
Add mailto=your@email.com for polite pool (faster responses).
# SSRN papers (source ID: S4210172589, NOT S4306400806 which is Europe PMC)
curl -s "https://api.openalex.org/works?filter=primary_location.source.id:S4210172589,default.search:social+preferences,publication_year:2024-2026&per_page=25&mailto=you@university.edu"
# NBER papers
curl -s "https://api.openalex.org/works?filter=primary_location.source.id:S4210174556,default.search:behavioral+economics&per_page=25&mailto=you@university.edu"
curl -s "https://api.openalex.org/works?search=network+formation+game+theory&filter=publication_year:2024-2026&per_page=25&sort=cited_by_count:desc&mailto=you@university.edu"
curl -s "https://api.openalex.org/works/doi:10.2139/ssrn.4812743?mailto=you@university.edu"
import requests
def openalex_search(query, source_id=None, year_from=2024, year_to=2026, per_page=25):
"""Search OpenAlex. source_id: S4210172589 (SSRN), S4210174556 (NBER), etc."""
filters = [f"default.search:{query}", f"publication_year:{year_from}-{year_to}"]
if source_id:
filters.insert(0, f"primary_location.source.id:{source_id}")
params = {
"filter": ",".join(filters),
"per_page": per_page,
"mailto": "you@university.edu"
}
data = requests.get("https://api.openalex.org/works", params=params).json()
results = []
for w in data.get("results", []):
pdf_urls = [loc["pdf_url"] for loc in w.get("locations", []) if loc.get("pdf_url")]
results.append({
"title": w["title"],
"doi": w.get("doi", "").replace("https://doi.org/", ""),
"year": w.get("publication_year"),
"authors": [a["author"]["display_name"] for a in w.get("authorships", [])],
"cited_by": w.get("cited_by_count", 0),
"pdf_urls": pdf_urls,
"landing_url": (w.get("primary_location") or {}).get("landing_page_url", ""),
})
return {"total": data.get("meta", {}).get("count", 0), "results": results}
Full reference: See
references/journal_identifiers.mdfor a comprehensive table of 77 verified OpenAlex Source IDs and CrossRef ISSNs covering Top 5 economics, AEA journals, finance, management, marketing, accounting, IS, and 15+ field journal categories.
| Source | OpenAlex ID | CrossRef ISSN |
|---|---|---|
| SSRN Electronic Journal | S4210172589 | 1556-5068 |
| NBER Working Papers | S2809516038 | N/A |
| American Economic Review | S23254222 | 0002-8282 |
| Quarterly Journal of Economics | S203860005 | 0033-5533 |
| Econometrica | S95464858 | 0012-9682 |
Warning: OpenAlex source IDs are opaque and not guessable. Always verify
via https://api.openalex.org/sources?search=journal+name before using a new ID.
For verified IDs of 77 journals, consult references/journal_identifiers.md.
primary_location.pdf_url is null for SSRN papers (Elsevier blocks it).
Check locations[].pdf_url for third-party repos — ~24% of SSRN papers have PDFs
via EconStor, IZA, MPRA, etc. These are real, downloadable PDFs.
Free, no key needed. Add mailto= for 50 req/sec (vs 1 req/sec without).
# All SSRN papers matching a query
curl -s "https://api.crossref.org/works?query=%22social+preferences%22&filter=prefix:10.2139,from-pub-date:2024-01-01&rows=25&sort=relevance&mailto=you@university.edu"
# See references/journal_identifiers.md for 77 verified ISSNs
# AER: 0002-8282, QJE: 0033-5533, JPE: 0022-3808, Econometrica: 0012-9682, REStud: 0034-6527
curl -s "https://api.crossref.org/journals/0002-8282/works?query=auction+mechanism&rows=10&mailto=you@university.edu"
curl -s "https://api.crossref.org/works/10.1257/aer.20171330?mailto=you@university.edu"
| Source | DOI Format | Example |
|---|---|---|
| SSRN | 10.2139/ssrn.{abstract_id} | 10.2139/ssrn.4812743 |
| NBER | 10.3386/w{number} | 10.3386/w34297 |
These predictable DOI formats allow constructing DOIs from paper IDs without making extra API calls.
CrossRef returns title, authors, DOI, date, journal — but no abstracts for SSRN papers (Elsevier doesn't submit them to CrossRef). Use OpenAlex for richer metadata.
Free, no key needed. Returns Atom XML. Rate limit: ~1 request per 3 seconds.
curl -s "https://export.arxiv.org/api/query?search_query=abs:social+preferences+AND+(cat:econ.TH+OR+cat:econ.GN)&max_results=20&sortBy=submittedDate&sortOrder=descending"
all: (full text), ti: (title), au: (author), abs: (abstract), cat: (category).
Boolean: AND, OR, ANDNOT. Exact phrase: %22social+preferences%22.
econ.TH (Theory), econ.GN (General), econ.EM (Econometrics).
Caveat: The cat: filter in search_query does not always reliably restrict results
to specified categories — arXiv may still return papers from other fields.
Verify category matches in results and filter client-side if needed.
https://arxiv.org/pdf/{id} # e.g. https://arxiv.org/pdf/2401.12345
https://arxiv.org/abs/{id} # abstract page
Free, no key needed. Returns JSON.
# Search
curl -s "https://www.nber.org/api/v1/working_page_listing/contentType/working_paper/_/_/search?page=1&perPage=20&q=social+preferences"
# Filter by Program (replace _/_ with programs/{name})
curl -s "https://www.nber.org/api/v1/working_page_listing/contentType/working_paper/programs/Labor+Studies/search?page=1&perPage=20&q=minimum+wage"
# New this week
curl -s "https://www.nber.org/api/v1/working_page_listing/contentType/working_paper/_/_/search?page=1&perPage=20&newThisWeek=true"
Labor Studies, Economic Fluctuations and Growth, Industrial Organization, Public Economics, Development Economics, International Finance and Macroeconomics, Corporate Finance, Asset Pricing, Health Economics, etc.
Authors field contains HTML <a> tags — strip with: re.sub(r'<[^>]+>', '', text)
No built-in date filter — API sorts by relevance. Filter client-side by displaydate.
https://www.nber.org/system/files/working_papers/w{number}/w{number}.pdf
Free, no key needed. Email as query param. 100,000 requests/day.
curl -s "https://api.unpaywall.org/v2/10.2139/ssrn.4812743?email=you@university.edu" \
| python3 -c "
import sys, json
d = json.load(sys.stdin)
print(f'OA: {d[\"is_oa\"]} ({d[\"oa_status\"]})')
pdf = (d.get('best_oa_location') or {}).get('url_for_pdf')
print(f'PDF: {pdf or \"none\"}')
# Check all locations for alternative PDFs
for loc in d.get('oa_locations', []):
if loc.get('url_for_pdf'):
print(f'Alt PDF: {loc[\"url_for_pdf\"]} ({loc[\"host_type\"]})')
"
| Status | Meaning |
|---|---|
gold | Published OA by publisher |
green | Free copy in a repository |
hybrid | OA article in subscription journal |
bronze | Free to read on publisher site |
closed | No free version found |
| Source | Unpaywall PDF Rate | Why |
|---|---|---|
| arXiv | ~100% | Native OA, direct PDF links |
| NBER | ~97% | Green OA via author/institution repos |
| SSRN | ~30% | Cloudflare blocks Unpaywall; only finds institutional repo mirrors |
For SSRN papers where Unpaywall returns url_for_pdf=null, check oa_locations[]
for institutional repositories (EconStor, university repos) — follow their landing pages
to find PDF links.
Free, no key needed. Rate limit: 100 requests per 5 minutes.
Warning: As of 2026, Semantic Scholar may return 429 errors frequently.
Consider registering for an API key at https://www.semanticscholar.org/product/api
for higher limits. Add header: x-api-key: YOUR_KEY.
# Search
curl -s "https://api.semanticscholar.org/graph/v1/paper/search?query=social+preferences+experiment&fields=title,year,authors,citationCount,externalIds,venue&limit=20&year=2024-2026"
# DOI lookup
curl -s "https://api.semanticscholar.org/graph/v1/paper/DOI:10.1257/aer.20171330?fields=title,year,authors,citationCount,abstract"
fieldsOfStudy=Economics,Sociology,Political+Science,Business,Psychology
Warning: The Economics filter is very strict and may return 0 results.
Often better to search without it and filter manually.
Best for: citation counts, finding related papers, author impact metrics. Not best for: SSRN-specific search (poor coverage), bulk downloading.
When APIs do not cover the need, Tavily can search any academic site. Particularly useful for SSRN (no public API) and as a fallback for any source.
# Via MCP tool
mcp__tavily__tavily-search({
"query": 'site:ssrn.com "social preferences" economics 2024 2025',
"search_depth": "advanced",
"max_results": 20,
"include_domains": ["ssrn.com", "papers.ssrn.com"]
})
# Also works for NBER, RePEc, etc.
mcp__tavily__tavily-search({
"query": 'site:nber.org "network formation" working paper',
"include_domains": ["nber.org"]
})
For finding all recent papers on a topic across multiple sources:
1. OpenAlex: broad search (all sources, richest metadata)
2. CrossRef prefix:10.2139: catch SSRN papers OpenAlex might miss
3. NBER API: NBER-specific search with program filtering
4. arXiv API: preprints in CS/AI/Physics/Econ
5. Tavily: sweep for anything the APIs missed
6. Deduplicate by DOI
SSRN has no public API. Use this cascade:
1. OpenAlex (filter: source.id:S4210172589) — best: 1 API call, rich metadata
2. CrossRef (filter: prefix:10.2139) — backup: structured DOI search
3. Tavily (include_domains: ssrn.com) — catches papers not yet in OpenAlex/CrossRef
Try sources in this order (most reliable first):
1. arXiv direct: https://arxiv.org/pdf/{id}
2. NBER direct: https://www.nber.org/system/files/working_papers/w{n}/w{n}.pdf
3. Unpaywall: check best_oa_location.url_for_pdf via DOI
4. OpenAlex: check locations[].pdf_url for third-party repo PDFs
5. Institutional repos: follow Unpaywall oa_locations landing pages
6. SSRN direct: construct Delivery.cfm URL (may be Cloudflare-blocked)
Always prefer zotero_add_by_doi over zotero_add_by_url:
10.2139/ssrn.{id}) and NBER (10.3386/w{number})| API | Rate Limit | Best Practice |
|---|---|---|
| OpenAlex | 10 req/sec (polite pool) | Add mailto= parameter |
| CrossRef | 50 req/sec with mailto=, 1/sec without | Always add mailto= |
| Unpaywall | 100K/day | Burst OK, no throttling needed |
| arXiv | ~1 req/3sec | Add time.sleep(3) between requests |
| NBER | No documented limit | Be polite, ~1 req/sec |
| Semantic Scholar | 100 req/5min | Add time.sleep(3) or use API key for higher limit |
| Tavily | Per plan | Use search_depth: "basic" when possible |
No reviews yet. Tell others what you thought.
No login needed. Share how it worked for you, ask a question, or note where it did not run.
No comments yet. Be the first to write one.
Turn a broad research idea into clear, testable questions. Compare familiar and less conventional approaches, structure the selected question around its population and methods, and assess variables, feasibility, and potential theoretical contributions.
Helps build a research framework by comparing theories, mapping relationships between variables, and deriving testable hypotheses. Explores less conventional options, examines weaknesses and competing explanations, and produces diagrams with anticipated reviewer objections.
Clarify the philosophical assumptions behind a research project and check whether they fit the proposed methods. Get a reasoned research stance, draft proposal wording, and guidance for explaining how the researcher's background and values shape the study.
Plan and draft academic papers through specialized agent roles covering literature, arguments, citations, and review. Get chapter guidance, revision roadmaps, Traditional Chinese and English abstracts, and documents formatted as LaTeX, DOCX, PDF, or Markdown.
Turn a detailed outline into a philosophy or interdisciplinary manuscript. Draft chapters with repeated quality reviews, check terminology and arguments across sections, and prepare the manuscript, evaluation reports, abstract, and metadata for submission.
Simulate academic peer review through five reviewer roles tailored to the paper's field. Receive separate critiques, an editorial decision, and a prioritized revision roadmap, or check whether a revised manuscript addresses earlier comments.