Scholar Mcp

scholar-mcp

[](https://pypi.org/project/scholar-mcp) [](https://www.python.org/) [](LICENSE) [](https://modelcontextprotocol.io)

Multi-source academic paper search, citation graph exploration, and PDF download as an MCP server. Designed for LLM agents doing research.

Fuses results from 9 academic sources via Reciprocal Rank Fusion, with PDF access across 10+ preprint servers.

Quick Start

Claude Code:

claude mcp add scholar -- uvx scholar-mcp

With API key (recommended, higher rate limits):

claude mcp add scholar -e S2_API_KEY=your_key -- uvx scholar-mcp

Claude Desktop (add to config):

{
  "mcpServers": {
    "scholar": {
      "command": "uvx",
      "args": ["scholar-mcp"]
    }
  }
}

> Requires Python 3.10+ and uv. No API key needed for basic use.

Tools

| Tool | Description | |------|-------------| | search_papers | Multi-source search with RRF fusion. Filters: year, venue, field, citations, open access | | get_paper | Paper details by S2 ID, DOI, ArXiv ID, PMID, or OpenAlex ID | | get_citations | Papers citing a given paper (impact-sorted) | | get_references | Papers referenced by a given paper | | recommend_papers | Similar papers via SPECTER2 embeddings | | search_authors | Researchers with h-index, affiliations, paper counts | | build_paper_graph | Citation graph with PageRank analytics and Mermaid visualization | | search_openreview | Conference papers (ICLR, NeurIPS, ICML) | | discover_field | Auto-map a research field: find surveys, foundations, recent trends, build citation graph | | save_papers | Save papers to a persistent collection for later reference | | list_saved_papers | List or search saved paper collections (persists across sessions) | | download_paper | Smart PDF download across 10+ sources | | read_paper | Download + extract text from PDF |

Search Sources

| Source | Coverage | Strength | |--------|----------|----------| | Semantic Scholar | 214M papers | SPECTER2 semantic search | | OpenAlex | 250M works | Best coverage, impact-ranked citations | | arXiv | CS/Math/Physics | Preprints | | PubMed | 36M biomedical | Medicine, biology | | Europe PMC | Biomedical + EU | PubMed superset | | Crossref | 150M DOIs | Metadata | | DBLP | CS bibliography | Conferences, proceedings | | INSPIRE-HEP | High-energy physics | Particle physics | | CORE | 250M open access | Institutional repositories |

PDF Download Chain

1. Semantic Scholar open access
2. arXiv direct
3. CORE (institutional repositories)
4. Preprint servers: bioRxiv, medRxiv, SSRN, ChemRxiv, PsyArXiv, EarthArXiv, SocArXiv, engrXiv, AgriXiv, SportRxiv, Preprints.org
5. Unpaywall (legal OA discovery)
6. PubMed Central
7. Sci-Hub (opt-in via SCIHUB_ENABLED=1)

Citation Graph

build_paper_graph builds an interactive citation network:

• BFS expansion with velocity-weighted priority (new + influential papers first)
• PageRank and betweenness centrality via networkx
• Pivot/bridge paper detection
• Topic filtering to keep graph focused
• Mermaid output with color-coded nodes (seed, high-cite, bridge)

build_paper_graph("Attention Is All You Need", max_hops=2, max_papers=20, topic_filter="attention transformer")

Configuration

| Variable | Default | Description | |----------|---------|-------------| | S2_API_KEY | - | Semantic Scholar API key (1 req/s) | | CORE_API_KEY | - | CORE API key | | OPENALEX_EMAIL | - | Email for Unpaywall + OpenAlex polite pool | | SCHOLAR_DOWNLOAD_DIR | ./downloads | PDF save directory | | SCIHUB_ENABLED | false | Enable Sci-Hub as last-resort source |

Development

git clone https://github.com/Liyux3/scholar-mcp.git
cd scholar-mcp
uv venv && uv pip install -e ".[dev]"
uv run pytest tests/                          # 42 unit tests
S2_API_KEY=... uv run python tests/smoke_test.py  # quick integration check

42 tests: relevance scoring (26), graph analytics (9), knowledge base (7).

License

MIT

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: Liyux3
• Source: Liyux3/scholar-mcp
• License: MIT

Install and usage instructions live in the source repository linked above.