Polymath MCP

An MCP (Model Context Protocol) server that aggregates free, keyless research sources for computer science, computer engineering, electronics and IT.

One server, one normalized output format, seventeen data sources. Every source works without an API key and without payment. Results from different sources are merged and deduplicated by DOI and arXiv id, so the same paper found on arXiv, Crossref and OpenAlex comes back as a single record that combines the best fields of each.

Why

Research data is scattered across many APIs, each with its own format, quirks and rate limits. Existing MCP servers each cover one slice. Polymath gives an agent a single interface where a paper, its open-access PDF, its citation count, its implementation on GitHub, the model trained from it on Hugging Face and the practical discussion around it on Hacker News or Stack Exchange are all one tool call apart.

Tools

Tool	What it does	Sources
search_papers	Search academic papers, deduplicated across sources	arXiv, Crossref, DBLP, Europe PMC, OpenAlex, CORE, Zenodo, Semantic Scholar, Hugging Face Papers
get_paper	Resolve one paper by DOI or arXiv id, merging every source that knows it, including open-access PDF link and citation counts	the above, plus Unpaywall and OpenCitations
search_code	Find repositories, e.g. the implementation of a paper	GitHub
search_hub	Search models or datasets, with links back to their papers	Hugging Face Hub
search_trends	Practitioner discussions and relevance signals	Hacker News, Stack Overflow, Electronics Stack Exchange
search_standards	RFCs and Internet-Drafts	IETF Datatracker
search_components	Electronic component documents: scanned datasheets and KiCad symbols	Internet Archive, KiCad libraries
list_sources	List every source and its category	-

Every search response is an envelope with results, sources_ok and sources_failed. Partial failure is the normal case for an aggregator: when a source is down or rate-limited, the others still answer and the envelope says exactly which sources contributed.

Installation

Requires Python 3.11+.

pip install git+https://github.com/Moreti2002/polymath-mcp

Or from a clone:

git clone https://github.com/Moreti2002/polymath-mcp
cd polymath-mcp
pip install .

Claude Code

claude mcp add polymath -- polymath-mcp

Claude Desktop / other MCP clients

{
  "mcpServers": {
    "polymath": {
      "command": "polymath-mcp"
    }
  }
}

Configuration

No API keys are needed. One optional environment variable:

• POLYMATH_EMAIL: a real contact e-mail. Unlocks the Unpaywall source (which requires it) and puts Crossref requests in its polite pool with better rate limits. Without it everything else still works.

{
  "mcpServers": {
    "polymath": {
      "command": "polymath-mcp",
      "env": { "POLYMATH_EMAIL": "you@example.com" }
    }
  }
}

Sources and their limits

All limits below are for keyless access, as observed in practice.

Source	Role	Keyless limit
arXiv	CS/EE preprints, primary	1 request / 3 s (self-imposed politeness)
Crossref	DOI metadata, primary	3 req/s in the polite pool
DBLP	Canonical CS bibliography (venues)	~1 req/s, aggressive blocking on bursts
Europe PMC	Full-text biomedical + applied ML	~10 req/s
OpenAlex	Enrichment by DOI (free); text search is credit-rationed (~100 searches/day)	1000 credits/day/IP
CORE	Institutional repository full-text	~10 req/min
Zenodo	Software and datasets with DOIs	30 req/min
Semantic Scholar	Citation graph, best effort only	shared anonymous pool, frequent 429
Unpaywall	Open-access PDF resolution by DOI	100k/day, requires POLYMATH_EMAIL
OpenCitations	Citation counts and references	unthrottled, high latency
GitHub	Repository search	10 req/min
Hugging Face	Models, datasets, papers	generous, undocumented
Hacker News (Algolia)	Discussion search	~10k req/h
Stack Exchange	Stack Overflow + Electronics SE	300 req/day/IP
IETF Datatracker	RFCs and drafts	unthrottled
Internet Archive	Scanned datasheets and databooks	unthrottled
KiCad libraries (GitLab)	Component symbol existence	unthrottled

The server caches responses in memory and throttles each source to stay within these limits. Sources with hard daily budgets (Stack Exchange, OpenAlex search) are cached the longest.

Known coverage gaps

• There is no legitimate keyless API for commercial electronic component catalogs (Octopart/Nexar, Digi-Key and Mouser all require credentials). search_components covers what keyless sources can: scanned datasheets on the Internet Archive and KiCad symbol libraries. For part selection discussion, search_trends includes the Electronics Stack Exchange.
• Papers with Code shut down in 2025; its role is covered by the Hugging Face Papers source.
• Semantic Scholar without a key shares a global anonymous pool and fails often. It is wired as best-effort and never blocks a search.

Architecture

src/polymath/
  server.py        MCP server and tool definitions
  models.py        normalized result models (Paper, CodeRepo, HubItem, ...)
  aggregate.py     concurrent fan-out with per-source failure isolation
  dedupe.py        cross-source paper merging (DOI, arXiv id, title)
  http.py          shared HTTP client, retries, per-source throttling
  cache.py         in-memory TTL cache
  providers/       one module per source, registered in a plug-in registry

Adding a source is one file: subclass Provider (or PaperLookupProvider), map the API response to the normalized models, decorate the class with @register. The aggregator, dedupe and MCP tools pick it up automatically.

Development

python -m venv .venv && source .venv/bin/activate
pip install -e ".[dev]"

pytest -m "not live"   # offline tests (mocked HTTP)
pytest -m live         # integration tests against the real APIs

Offline tests must always pass. Live tests depend on third-party services and may fail when a source is down or rate-limited; CI runs them as non-blocking.

License

MIT. See LICENSE.