Clinical Trial Design MCP Server

A Claude Code plugin and MCP server for end-to-end clinical trial design. clinical-trial-design helps biostatisticians and clinical trialists design Phase 2 and Phase 3 confirmatory studies through a conversational interface, backed by validated R packages (gsDesign, gsDesign2, graphicalMCP). Its 9 documented tools cluster into design, validate, verify.

People connecting design tools to Claude, Cursor, VS Code, or another MCP client. The project is written in R.

VERIFIED ACTIVE

LAST COMMIT 2026-05-03 · ★ 2 · #64 OF 74 MAINTAINED DESIGN · VERIFIED 2026-08-25

Apache-2.0 · R · how we verify → /methodology

01 · Install Clinical Trial Design

before you install - you'll need

DESIGNR_RSCRIPT

Environment variables documented in the project's README - it lists which are required and which have defaults.

Claude Code

claude mcp add wei-ai-lab-clinical-trial-design -- npx -y clinical-trial-design

Claude Desktop / Cursor / VS Code - add to config

{
  "mcpServers": {
    "wei-ai-lab-clinical-trial-design": {
      "command": "npx",
      "args": [
        "-y",
        "clinical-trial-design"
      ]
    }
  }
}

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

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

license Apache-2.0 - declared in the repository

npm package clinical-trial-design - unscoped; check the name against the project README before installing

registry namespace io.github.wei-ai-lab is GitHub-verified and matches the repo owner

03 · What Clinical Trial Design can do

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

What you can build

An agent gets 9 documented tools across design, validate, verify, including design_binary, design_continuous, design_survival, design_co_primary.

Capability map

Tools grouped from the project's README - what Clinical Trial Design lets an agent do.

Design

7 tools - e.g. event / no-event; mean difference; time-to-event

design_binary · design_continuous · design_survival · design_co_primary · design_multi_population · design_graphical_multiplicity…

Validate

1 tool - e.g. Replay a benchmark case through its matching design tool and diff against expected values within tolerance.

validate_against_benchmark

Verify

1 tool - e.g. Monte Carlo cross-check of any result. Closed-form simulation under H0 and H1; ±2 pp power / ±0.5 pp Type I tolerance gate. Supports fixed and GS designs on bin

verify_design

Latest releases

v0.0.14 · 2026-05-03

v0.0.14 - Auto-discover Rscript; fix #1 (Posit Workbench install) · Patch release. Fixes the rscript_spawn_failed error reported by users · in Posit Workbench, RStudio Server, and other sandboxed Claude Code · hosts…

v0.0.13 · 2026-05-01

v0.0.13 - Architectural fixes from the M3+M4 comparison · Three parked items closed: · events_calc='schoenfeld' (new default on PH GS) - closes the ~1pp · empirical-power gap; matches regulatory convention and arm A's…

v0.0.12 · 2026-05-01

v0.0.12 - Pre-beta polish · The "pre-beta" release. Final engineering work before v0.5.0 beta. Adds · release-gate CI, API stability commitments, 5-trial examples gallery, · and conference talk abstracts. Everything…

04 · Who maintains Clinical Trial Design

clinical-trial-design is maintained by wei-ai-lab. It's the only MCP server we track from this author; the repo dates to Apr 2026.

05 · Facts

repository: github.com/wei-ai-lab/clinical-trial-design
category: design - ranked #64 of 74 actively-maintained design servers as of 2026-08-25.
registry: io.github.wei-ai-lab/clinical-trial-design (active, first published 2026-04-29)
packages: npm:clinical-trial-design

06 · Clinical Trial Design FAQ

Is Clinical Trial Design still maintained?

Yes - as of 2026-08-25, its last commit was 2026-05-03. We re-verify nightly.

What can Clinical Trial Design do?

An agent gets 9 documented tools across design, validate, verify, including design_binary, design_continuous, design_survival, design_co_primary.

How do I install Clinical Trial Design?

Run `npx -y clinical-trial-design`. The README documents one environment variable (DESIGNR_RSCRIPT) to set first. You can also paste the ready-made client config above.

Does Clinical Trial Design run locally?

Yes - it's a stdio server: it runs on your machine (via npx) with your user's permissions. Your data stays local unless the server itself calls external APIs.

07 · Alternatives to Clinical Trial Design

Alternatives to Clinical Trial Design

Maintained design servers if Clinical Trial Design isn't the fit.

More design MCP servers · Zenith · UI Ux Suite · Canvas MCP (admin978) · Human Standards · The Game Crafter