Clinicaltrialsgov MCP Server

clinicaltrialsgov-mcp-server Search ClinicalTrials.gov trials, retrieve study details and results, and match patients to eligible trials via MCP. STDIO or Streamable HTTP. Its 7 documented tools cover clinicaltrials, study.

People who work with clinicaltrials and study and want it reachable from Claude, Cursor, VS Code, or another MCP client. The project is written in TypeScript.

VERIFIED ACTIVE

LAST COMMIT 2026-09-13 · ★ 94 · #4 OF 71 MAINTAINED SCIENCE & HEALTH · VERIFIED 2026-09-18

Apache-2.0 · TypeScript servers · how we verify → /methodology

01 · Install Clinicaltrialsgov MCP Server

before you install - you'll need

Set MCP_TRANSPORT_TYPE, MCP_LOG_LEVEL before connecting.

Claude Code

claude mcp add cyanheads-clinicaltrialsgov-mcp-server --transport http https://clinicaltrials.caseyjhand.com/mcp

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "cyanheads-clinicaltrialsgov-mcp-server": {
      "url": "https://clinicaltrials.caseyjhand.com/mcp"
    }
  }
}

Same JSON for Cursor. For VS Code, rename the top-level key from `mcpServers` to `servers`.

Using another client? Same JSON, different key

Claude Desktop · mcpServers

Cursor · mcpServers

VS Code · servers

Windsurf · mcpServers

Zed · context_servers

Cline · mcpServers

Roo Code · mcpServers

Continue · mcpServers

LibreChat · mcpServers

Gemini CLI · mcpServers

Codex CLI · mcp_servers

Full setup guides: every client.

02 · Evidence

https://clinicaltrials.caseyjhand.com/mcp

transport: streamable-http

endpoint alive - responded to MCP initialize · probed 2026-09-17

Security posture

What to check before giving this server access to your agent - from the registry, GitHub, and our own probes. We don't score safety; we show what's verifiable.

runs as local process (stdio) - runs on your machine with your user's permissions · remote - your agent's requests go to clinicaltrials.caseyjhand.com

endpoint auth accepted our unauthenticated MCP initialize - no credentials needed to connect

license Apache-2.0 - declared in the repository

npm package clinicaltrialsgov-mcp-server - unscoped; check the name against the project README before installing

registry namespace io.github.cyanheads is GitHub-verified and matches the repo owner

03 · What Clinicaltrialsgov MCP Server can do

Prose above is summarized from the project's README and registry record - no invented capabilities.

What you can build

With this server connected, an agent can search studies with full-text and field-specific queries, status/phase/geographic filters, pagination, sorting, and field selection, fetch a single study by NCT ID - full protocol record with optional location/outcome/reference caps, discover valid values for API fields, with per-value study counts, and resolve valid field names - keyword search, path drill-down, or top-level overview.

The 7 tools it gives your agent

Extracted from the project's README - what clinicaltrialsgov-mcp-server lets an agent do.

clinicaltrials_search_studies
- Search studies with full-text and field-specific queries, status/phase/geographic filters, pagination, sorting, and field selection
clinicaltrials_get_study_record
- Fetch a single study by NCT ID - full protocol record with optional location/outcome/reference caps
clinicaltrials_get_study_count
- Fast total study count for a query, without fetching data
clinicaltrials_get_field_values
- Discover valid values for API fields, with per-value study counts
clinicaltrials_get_field_definitions
- Resolve valid field names - keyword search, path drill-down, or top-level overview
clinicaltrials_get_study_results
- Fetch posted results - outcomes, adverse events, participant flow, baseline - for completed studies
clinicaltrials_find_eligible
- Match patient demographics and conditions to eligible recruiting trials

Latest releases

v2.9.7 · 2026-09-13

mcp-ts-core 0.13.0: blank config values fall back to defaults · Blank or unsubstituted ${...} config values read as unset, so defaults apply (mcp-ts-core 0.13.0, cyanheads/mcp-ts-core#427) · manifest.json wires its…

v2.9.6 · 2026-09-12

Field statistics, argument validation, document links · get_field_values numeric/date/longest statistics (#119) · repeated-ancestor multiValued (#121) · get_field_definitions typed argument validation…

v2.9.5 · 2026-09-12

search_studies input validation, field parity, page exhaustion; find_eligible location phrases · geoFilter is validated before the upstream call - a bad radius, unit, or coordinate now fails as geo_invalid instead of…

04 · Who maintains Clinicaltrialsgov MCP Server

clinicaltrialsgov-mcp-server is maintained by cyanheads. We track 125 MCP servers from cyanheads - 119 actively maintained, 1,816 combined GitHub stars, oldest repo from Dec 2024. Full record: all servers from cyanheads.

  1. obsidian-mcp-server Read, write, search, and surgically edit Obsidian notes, tags, and frontmatter via MCP. ★ 681
  2. mcp-ts-core Agent-native TypeScript framework for MCP servers. ★ 151
  3. pubmed-mcp-server Search PubMed/Europe PMC, fetch articles and full text (PMC/EPMC/Unpaywall), citations, MeSH terms. ★ 148
  4. git-mcp-server Comprehensive Git MCP server enabling native git tools including clone, commit, worktree, & more. ★ 240
  5. ntfy-mcp-server Send, manage, and replay ntfy push notifications via MCP. ★ 22
  6. mcp-ts-template TypeScript template for building MCP servers with declarative tooling, observability, and auth. ★ 151

05 · Facts

repository
github.com/cyanheads/clinicaltrialsgov-mcp-server
category
science & health - ranked #4 of 71 actively-maintained science & health servers as of 2026-09-18.
release cadence
10+ releases in the last 90 days (latest 2026-09-13)
registry
io.github.cyanheads/clinicaltrialsgov-mcp-server (active, first published 2025-10-02 · 69 versions)
packages
npm:clinicaltrialsgov-mcp-server · npm:clinicaltrialsgov-mcp-server

06 · Clinicaltrialsgov MCP Server FAQ

Is Clinicaltrialsgov MCP Server still maintained?

Yes - as of 2026-09-18, its last commit was 2026-09-13 and it shipped 10+ releases in the last 90 days. We re-verify nightly.

What can Clinicaltrialsgov MCP Server do?

With this server connected, an agent can search studies with full-text and field-specific queries, status/phase/geographic filters, pagination, sorting, and field selection, fetch a single study by NCT ID - full protocol record with optional location/outcome/reference caps, discover valid values for API fields, with per-value study counts, and resolve valid field names - keyword search, path drill-down, or top-level overview.

How do I install Clinicaltrialsgov MCP Server?

Run `npx -y clinicaltrialsgov-mcp-server`. The README documents 2 environment variables (MCP_TRANSPORT_TYPE, MCP_LOG_LEVEL) to set first. Set MCP_TRANSPORT_TYPE, MCP_LOG_LEVEL before connecting. You can also paste the ready-made client config above.

Does Clinicaltrialsgov MCP Server require authentication?

No - the endpoint accepted our unauthenticated MCP initialize when probed on 2026-09-17; you can connect without credentials.

07 · Alternatives to Clinicaltrialsgov MCP Server

Alternatives to Clinicaltrialsgov MCP Server

Maintained science & health servers if Clinicaltrialsgov MCP Server isn't the fit.

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  4. Pubmed MCP Server Search PubMed/Europe PMC, fetch articles and full text (PMC/EPMC/Unpaywall), citations, MeSH terms. ★ 148 · 2026-09-13
  5. FHIR MCP Server MCP server providing seamless access to FHIR APIs for AI tools and healthcare applications ★ 136 · 2026-09-04
  6. Patsnap Patent & Literature Search Search 200M+ patents and 216M+ scientific papers using natural language and structured filters. ★ 79 · 2026-08-06

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