OpenAlex Literature Search Skill

Searches OpenAlex — a free, open index of 250M+ scholarly works — for peer-reviewed publications on petroleum engineering, geochemistry, and critical minerals topics.

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API Key Handling

No API key required. The OpenAlex API is fully public.

Polite pool (recommended): Include a mailto: address in the User-Agent header for faster responses and higher rate limits (100k requests/day vs 10/second throttle):

-H "User-Agent: OpenAlexClient/1.0 (mailto:research@mail.wvu.edu)"

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Data Sources and API Structure

Base URL: https://api.openalex.org

Key Endpoints

Endpoint	What It Returns
/works	Publications: articles, books, theses, conference papers
/authors	Author profiles with publication counts and h-index
/sources	Journals and repositories
/concepts	Controlled vocabulary topic tags
/institutions	Institutional affiliations

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Workflow

Step 1 — Resolve Search Terms

Map user intent to OpenAlex search parameters:

User Intent	Query Strategy
Topic keyword search	?search=direct+lithium+extraction
Title-specific search	?filter=title.search:produced+water
Open access only	Add filter=open_access.is_oa:true
Recent papers	Add filter=publication_year:>2019
Specific journal	Add filter=primary_location.source.display_name:Desalination
By author	?filter=author.display_name:smith+lithium
Most cited	Add sort=cited_by_count:desc

Step 2 — Search Works

# Basic keyword search, sorted by citation count
curl -s "https://api.openalex.org/works?search=direct+lithium+extraction+produced+water&per-page=10&sort=cited_by_count:desc" \
  -H "User-Agent: OpenAlexClient/1.0 (mailto:research@mail.wvu.edu)"

# Filtered: open access papers after 2019
curl -s "https://api.openalex.org/works?search=Marcellus+shale+lithium&filter=open_access.is_oa:true,publication_year:>2019&per-page=10&sort=cited_by_count:desc" \
  -H "User-Agent: OpenAlexClient/1.0 (mailto:research@mail.wvu.edu)"

# Multiple filters with comma separation
curl -s "https://api.openalex.org/works?filter=title.search:produced+water+treatment,publication_year:>2020&per-page=15&sort=publication_date:desc" \
  -H "User-Agent: OpenAlexClient/1.0 (mailto:research@mail.wvu.edu)"

Step 3 — Parse Response

{
  "meta": {"count": 1247, "page": 1, "per_page": 10},
  "results": [
    {
      "id": "https://openalex.org/W2741809807",
      "doi": "https://doi.org/10.1016/j.watres.2020.116198",
      "title": "Lithium recovery from produced water: A review",
      "display_name": "Lithium recovery from produced water: A review",
      "publication_year": 2020,
      "publication_date": "2020-09-15",
      "primary_location": {
        "source": {"display_name": "Water Research", "issn_l": "0043-1354"}
      },
      "authorships": [
        {"author": {"display_name": "Jane Smith"}, "institutions": [{"display_name": "WVU"}]}
      ],
      "cited_by_count": 312,
      "open_access": {"is_oa": true, "oa_url": "https://example.com/paper.pdf"},
      "abstract_inverted_index": {"Lithium": [0], "recovery": [1], "from": [2]},
      "concepts": [{"display_name": "Lithium", "score": 0.95}]
    }
  ]
}

Step 4 — Reconstruct Abstract

OpenAlex stores abstracts as an inverted index {word: [positions]}. Reconstruct by sorting positions:

import json

def reconstruct_abstract(inverted_index):
    if not inverted_index:
        return "(abstract not available)"
    word_positions = []
    for word, positions in inverted_index.items():
        for pos in positions:
            word_positions.append((pos, word))
    word_positions.sort(key=lambda x: x[0])
    return " ".join(w for _, w in word_positions)

Step 5 — Output

Format as citation table with narrative summary.

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Output Format

## Literature Search Results: Direct Lithium Extraction from Produced Water

**Search query:** "direct lithium extraction produced water"
**Total results in OpenAlex:** 1,247
**Showing:** Top 10 by citation count

| Title | Authors | Year | Journal | Citations | OA |
|-------|---------|------|---------|-----------|-----|
| Lithium recovery from produced water: A review | Smith et al. | 2020 | Water Research | 312 | Yes |
| DLE sorbent performance in high-TDS brines | Jones & Liu | 2021 | Desalination | 187 | No |

**Key Themes:** Research on DLE from produced water clusters around three
themes: (1) sorbent material development (H₂TiO₃, Al-based), (2) economic
viability at sub-100 mg/L Li concentrations, and (3) Appalachian basin
brine characterization for resource estimation.

**Data source:** OpenAlex (https://openalex.org). Coverage: 250M+ works.
Open access links where available via Unpaywall integration.

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Pagination

OpenAlex supports cursor-based pagination for large result sets:

# First page — get cursor from response meta.next_cursor
curl -s "https://api.openalex.org/works?search=lithium+brine&per-page=200&cursor=*" \
  -H "User-Agent: OpenAlexClient/1.0 (mailto:research@mail.wvu.edu)"

# Subsequent pages using next_cursor value
curl -s "https://api.openalex.org/works?search=lithium+brine&per-page=200&cursor=CURSOR_VALUE" \
  -H "User-Agent: OpenAlexClient/1.0 (mailto:research@mail.wvu.edu)"

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Error Handling

Condition	Meaning	Action
HTTP 429	Rate limit exceeded	Add mailto: User-Agent for polite pool; wait 1s
meta.count = 0	No results	Broaden search terms, remove filters
abstract_inverted_index null	No abstract available	Note "(abstract restricted by publisher)"
open_access.oa_url null but is_oa: true	OA version not indexed	Check publisher DOI directly
Very large count (>10,000)	Too broad	Add year filter or concept filter
DOI resolves to paywall	Publisher restriction	Note in output; suggest interlibrary loan

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Filter Reference

Common filter combinations for PNGE research:

# Appalachian basin shale research, last 5 years, open access
filter=title.search:Marcellus+shale,publication_year:>2019,open_access.is_oa:true

# DLE technology papers, highly cited
filter=title.search:direct+lithium+extraction&sort=cited_by_count:desc

# WVU-affiliated publications
filter=institutions.display_name:West+Virginia+University

# Papers in specific journal
filter=primary_location.source.issn:1385-8947

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Caveats

• OpenAlex coverage is strong for journal articles (>2000 onward) and weaker for conference papers and technical reports. For DOE reports, use pnge:doe-osti instead.
• Abstract reconstruction from the inverted index may have minor formatting artifacts (no punctuation in some cases).
• Citation counts are updated periodically, not in real-time.
• Some publisher abstracts are not available due to licensing restrictions.
• For USGS publications, pnge:usgs-pubs provides better coverage than OpenAlex.