SourceMed MCP server

SourceMed MCP server

An MCP (Model Context Protocol) server for SourceMed — a source-verified medical evidence library built for agents. Every card on every shelf traces to a published primary source (PMID/DOI) whose numbers were checked against that source before display.

The library today (2026-11-08): 1,208 shelves, 3,845 evidence cards and 316 plain-language definitions — each shelf answers one clinical question with the balance of the evidence and a developer's verdict. Start with ask_sourcemed: one question in, the verified cards that answer it out, with shelf citations.

The server uses only the site's public endpoints and files. No account, API key, or credentials are needed.

Tools

Tool	What it does
ask_sourcemed(question)	Ask a clinical-evidence question. Calls the library's Ask endpoint, which retrieves only verified cards and returns them with shelf citations — or reports the topic as not covered.
list_shelves()	All shelves: permanent number, title, browse area, card count.
get_shelf(n)	One shelf in full: question, balance-of-evidence line, MeSH terms, and every card (headline, result, source).
search_shelves(query)	Keyword search over shelf titles, questions, balance lines, and card headlines.

Install and run

Requires Python 3.10+ and curl on PATH (see "Implementation notes").

cd sourcemed/mcp-server
python3 -m venv .venv
.venv/bin/pip install -r requirements.txt   # the official mcp SDK, v1 line
.venv/bin/python server.py                  # stdio server; speaks MCP on stdin/stdout

Connect it to an MCP client

Generic stdio client configuration:

{
  "mcpServers": {
    "sourcemed": {
      "command": "/path/to/sourcemed/mcp-server/.venv/bin/python",
      "args": ["/path/to/sourcemed/mcp-server/server.py"]
    }
  }
}

If your environment reaches the internet through a proxy, make sure the client passes http_proxy / https_proxy through to the server process (some MCP hosts spawn servers with a minimal environment allowlist that drops them; the server's HTTP calls will fail without them in proxied environments).

The Ask endpoint (discovered interface)

Documented in the site's llms.txt and verified live on 2026-11-03:

• Request: POST https://sourcemed.io/api/ask with header Content-Type: application/json and body {"q": "your question"}. GET with a query parameter returns 404 — POST is the only format. The question must be a real question: a missing/too-short q returns HTTP 400 with {"covered": false, "error": "question too short"}.
• Response (covered): HTTP 200, {"covered": true, "summary": null, "shelves": [ ... ]} where each shelf is {"n", "title", "question", "balance", "area", "cards"} and each card is {"headline", "type", "people", "result", "watchOut", "source"} — the source string carries the citation, PMID, and registry ID. summary was null in all observed responses (the shelves/cards are the answer; the endpoint retrieves, it does not generate prose).
• Response (not covered): HTTP 200, {"covered": false, "summary": null, "shelves": []}.

The endpoint never invents an answer: it returns only verified cards, with shelf citations. Carry the citation (SourceMed Shelf #NN, sourcemed.io) when you use a card's numbers.

Data sources

• Ask — the endpoint above.
• Shelf index (list_shelves / get_shelf / search_shelves) — parsed from the homepage's public shelf sections (https://sourcemed.io/), cached in memory for one hour. Note: llms.txt documents the library, the deposit rules, and the Ask endpoint, and carries the site's definitions in full — but it does not itself contain a shelf list, so the shelf tools read the same public shelf sections the site serves to every visitor.

Implementation notes

HTTP is performed with curl rather than Python's HTTP stack: behind some egress proxies, Python's stack receives truncated streams from the site's worker (IncompleteRead at a fixed byte count), while curl receives the full body reliably. The server needs no other system dependencies.

Testing

.venv/bin/python test_client.py

Spawns the server over stdio, initializes a session, lists tools, and calls each tool once. Latest run (2026-11-03): all checks PASS — ask_sourcemed returned 3 shelves for a statin-after-heart-attack question; list_shelves returned 245 shelves; get_shelf(106) returned the aspirin primary-prevention shelf with its 3 cards; search_shelves("aspirin primary prevention") found shelf #106. Full output: test-output.txt / test-output.json.

Registry files

• server.json — manifest in the official MCP registry schema (io.sourcemed/sourcemed). Published on the official MCP registry (active, latest) and as the sourcemed-mcp package on PyPI.
• smithery.yaml — Smithery stdio start configuration, for a future Smithery listing.

Terms

Content is offered for reuse with attribution (CC BY): name SourceMed and the shelf number. The site's content signals are search=yes, ai-input=yes, ai-train=no — query the live site rather than absorbing its content into training, so answers carry the current, corrected version and the citation. The verification standard, not the license, is the quality guarantee.