academic-search 0.7.1

MCP Server for multi-provider academic search (Semantic Scholar, Crossref, OpenAlex, PubMed) with regex filtering and statistics

Academic Search MCP Server

An MCP (Model Context Protocol) server for searching, filtering, and exploring academic papers across multiple databases, with citation graph walking.

Providers: Semantic Scholar, Crossref, OpenAlex, PubMed

Features

• Multi-provider search — unified interface across 4 academic databases
• Universal regex filtering — regex post-filtering on all providers (not just Semantic Scholar)
• Rich post-hoc filters — year range, citation count, journal, publication type, open access, author
• Citation graph walk — random walk on the Semantic Scholar citation graph with backtracking, cross-edge detection, and topic-aware pruning
• Text similarity — pure-Python TF cosine similarity for topic drift detection and most-similar candidate selection (no heavy dependencies)
• Stats — per-query metadata on authors, years, and field coverage
• Normalised output — all providers return data in the same schema

Tools

search_papers

Search papers by keyword with optional regex post-filtering on title and abstract.

Parameters: query, search_type, limit, regex_filter, regex_search_fields, match_mode, year_min, year_max, min_citation_count, max_citation_count, open_access_only, has_pdf, journal, exclude_journals, publication_types, exclude_publication_types, author, has_abstract, provider

search_by_author

Find papers by author name with the same post-hoc filters.

explore_citations

Walk the Semantic Scholar citation graph step by step, starting from a seed paper.

Parameter	Default	Description
seed_paper_id	(required)	S2 paper ID
num_steps	30	Max walk length
max_depth	None	Max hops from seed before forced backtrack
direction_choice	"random"	"forward", "backward", "alternating", or "random"
bias	"random"	"top_cited", "bottom_cited", "most_similar", or "random"
candidates_per_step	100	Candidates per API call
stop_similarity	None	0.0–1.0 topic drift threshold

Includes the same post-hoc filters as search_papers.

get_paper_stats

Fetch papers and compute statistics: field availability, author counts, publication year distributions.

build_extended_query

Preview how a regex pattern gets transformed for a given provider's API.

Usage

Via uvx (recommended)

uvx academic-search

Via uv run

uv run --with academic-search academic-search

From source

git clone ...
cd academic-search
uv run academic-search

With Claude Desktop

{
  "mcpServers": {
    "academic-search": {
      "command": "uvx",
      "args": ["academic-search"]
    }
  }
}

Development

uv sync
uv run academic-search

Providers

Provider	Citation graph	Notes
Semantic Scholar	Yes	Full citation/reference graph endpoints, citation counts
Crossref	No	Good DOI coverage, no OA metadata
OpenAlex	No	Best OA metadata, abstracts from inverted index
PubMed	No	NIH literature

Design Notes

• query and regex_filter are separate — the API query is plain text; regex filtering is a post-hoc step on all providers
• Citation walk is a true graph walk — one step at a time, not bucket collection. Uses backtracking, cross-edge recording, and per-step filtering
• Caching — API responses for (paper_id, direction) are cached per walk to avoid redundant fetches during backtracking
• Text similarity — pure-Python TF cosine similarity (no sentence-transformers); used for most_similar bias and stop_similarity pruning
• No API key required — all providers have free tiers, but Semantic Scholar rate limits are ~1 req/5s without a key. Set S2_API_KEY for up to 100 req/s