Clinicaltrialsgov MCP Server - install & status [2026]

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 2026-09-30

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

v2.9.10 · 2026-09-22

per-group adverse events, distance-ranked site admission · get_study_results summary-mode adverse events report per-group byGroup counts against an eventGroups roster, ranked by the largest single group, not a pooled…

v2.9.9 · 2026-09-22

mcp-ts-core 0.13.6, search results flags, input normalization · search_studies compact index gains hasResults, startDate, primaryCompletionDate (#139) · statusFilter and NCT ID inputs normalize case/spacing variants…

v2.9.8 · 2026-09-18

mcp-ts-core 0.13.4, declared stateless session mode · Declared stateless session mode - createApp now sets sessionMode: 'stateless'; .env.example sets MCP_SESSION_MODE=stateless actively, and the README config table…

04 · Who maintains Clinicaltrialsgov MCP Server

clinicaltrialsgov-mcp-server is maintained by cyanheads. We track 137 MCP servers from cyanheads - 131 actively maintained, 1,856 combined GitHub stars, oldest repo from Dec 2024. Full record: all servers from cyanheads.

05 · Facts

repository: github.com/cyanheads/clinicaltrialsgov-mcp-server
category: science & health - ranked #5 of 75 actively-maintained science & health servers as of 2026-09-30.
release cadence: 10+ releases in the last 90 days (latest 2026-09-22)
registry: io.github.cyanheads/clinicaltrialsgov-mcp-server (active, first published 2025-10-02 · 72 versions)
packages: npm:clinicaltrialsgov-mcp-server · npm:clinicaltrialsgov-mcp-server

06 · Clinicaltrialsgov MCP Server FAQ

Is Clinicaltrialsgov MCP Server still maintained?

Yes - as of 2026-09-30, its last commit was 2026-09-22 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 2026-09-30; 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.

More science & health MCP servers · Eurostat MCP Server · Medical Codes MCP Server · Oecd MCP Server · Pubchem MCP Server

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