Clinical Trials MCP Server

A comprehensive Model Context Protocol (MCP) server that provides access to the ClinicalTrials.gov API, enabling researchers, clinicians, and developers to access real-time clinical trial data programmatically.

Developed by bachstudio

🚀 Quick Start with npx (Recommended)

No installation required! Use npx to run the server directly:

{
  "mcpServers": {
    "clinical-trials": {
      "command": "npx",
      "args": ["-y", "bach-clinical-trials"]
    }
  }
}

Save this configuration and restart your MCP client. The npx command will automatically download and run the latest version from npm.

Package URL: https://www.npmjs.com/package/bach-clinical-trials

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Overview

The Clinical Trials MCP server exposes the full ClinicalTrials.gov API v2.0.4 functionality through 18 specialized MCP tools, allowing you to search, analyze, and retrieve detailed information about clinical trials worldwide directly from your MCP-enabled environment.

Features

Core Search Tools

search_studies - General search with comprehensive filters (condition, intervention, location, phase, status, age, sex)
get_study_details - Detailed study information by NCT ID with complete metadata
search_by_condition - Condition-focused search with eligibility criteria
search_by_location - Geographic-based search with distance radius filtering
search_by_sponsor - Organization and sponsor-based search with sponsor type filtering
search_by_intervention - Treatment, drug, and intervention-focused search

Specialized Search Tools

get_recruiting_studies - Currently recruiting trials with active contact information
search_by_date_range - Temporal search by study start and completion dates
get_studies_with_results - Completed trials with published results
search_rare_diseases - Specialized search for rare diseases and orphan conditions
get_pediatric_studies - Pediatric-specific trials for children and adolescents
search_international_studies - Multi-country international trials

Advanced Analysis Tools

get_similar_studies - Find studies similar to a reference NCT ID by condition, sponsor, or phase
search_by_primary_outcome - Search by primary outcome measures and endpoints
search_by_eligibility_criteria - Advanced eligibility filtering with inclusion/exclusion keywords
get_study_timeline - Timeline analysis with current, completed, and upcoming studies
get_trial_statistics - Aggregate statistics and analytics with grouping capabilities

Data Quality Features

Real-time data access (updated daily Monday-Friday)
NCT ID validation with regex patterns
Comprehensive JSON Schema validation
Geographic coordinate data for study locations
Contact information for recruiting studies
Robust error handling and timeout protection

Installation

Prerequisites

Node.js 16+ (install from nodejs.org)
No API key required (ClinicalTrials.gov API is publicly accessible)

Setup Steps

Navigate to your MCP directory:

   cd ~/Documents/Claude/MCP  # or your preferred MCP directory

The server is already built and configured:

   ls clinical-trials-server/
   # Should show: build/ src/ package.json tsconfig.json README.md

Verify build:

   cd clinical-trials-server
   ls build/
   # Should show: index.js (executable)

Configuration

Add this to your claude_desktop_config.json:

macOS: ~/Library/Application Support/Claude/claude_desktop_config.json
Windows: %APPDATA%/Claude/claude_desktop_config.json

{
  "mcpServers": {
    "clinical-trials": {
      "command": "node",
      "args": ["path/to/clinical-trials-server/build/index.js"],
      "autoApprove": [
        "search_studies",
        "get_study_details",
        "search_by_condition",
        "search_by_location",
        "get_recruiting_studies",
        "search_by_sponsor",
        "search_by_intervention",
        "get_trial_statistics"
      ]
    }
  }
}

Note: Replace path/to/clinical-trials-server with the absolute path to your server directory.

Usage Examples

Search for Cancer Trials

{
  "condition": "cancer",
  "phase": "PHASE3",
  "status": "RECRUITING",
  "pageSize": 10
}

Get Detailed Study Information

{
  "nctId": "NCT05882279"
}

Find Trials by Location

{
  "country": "United States",
  "city": "Boston",
  "distance": 50,
  "pageSize": 5
}

Search for Pediatric Studies

{
  "condition": "diabetes",
  "ageRange": "CHILD",
  "recruitmentStatus": "RECRUITING"
}

Get Recruiting Trials with Contacts

{
  "condition": "alzheimer",
  "location": "California",
  "pageSize": 5
}

Find Similar Studies

{
  "nctId": "NCT12345678",
  "similarityType": "CONDITION",
  "pageSize": 10
}

Advanced Eligibility Search

{
  "minAge": "18 Years",
  "maxAge": "65 Years",
  "sex": "ALL",
  "healthyVolunteers": false,
  "condition": "hypertension",
  "inclusionKeywords": "medication",
  "exclusionKeywords": "pregnant"
}

Get Trial Statistics

{
  "groupBy": "phase",
  "filters": {
    "condition": "diabetes",
    "status": "RECRUITING"
  }
}

API Reference

Search Parameters

Common Parameters:

pageSize - Number of results (1-100, default: 10)
condition - Medical condition or disease
phase - Study phase: PHASE1, PHASE2, PHASE3, PHASE4, NA
status - Recruitment status: RECRUITING, NOT_YET_RECRUITING, COMPLETED, etc.

Location Parameters:

country - Country name
state - State or province
city - City name
distance - Search radius in miles (1-500)

Eligibility Parameters:

sex - ALL, FEMALE, MALE
age - CHILD, ADULT, OLDER_ADULT
minAge/maxAge - Age ranges (e.g., "18 Years", "65 Years")
healthyVolunteers - Boolean for healthy volunteer acceptance

Date Parameters:

startDateFrom/startDateTo - Study start date range (YYYY-MM-DD)
completionDateFrom/completionDateTo - Completion date range (YYYY-MM-DD)

Response Format

All tools return structured JSON data including:

Study metadata (NCT ID, title, status, phase, sponsor)
Location information with geographic coordinates
Eligibility criteria and contact information
Timeline data and key dates
Comprehensive search criteria documentation

NCT ID Format

All NCT IDs must follow the pattern: NCT######## (NCT followed by 8 digits)

Error Handling

The server includes comprehensive error handling for:

Network Issues: 30-second timeout protection with retry logic
Invalid Parameters: JSON Schema validation with descriptive error messages
API Errors: Proper HTTP status code handling and error reporting
Missing Data: Graceful handling of optional fields and missing information
Rate Limiting: Built-in request throttling and error recovery

Common error responses include:

{
  "error": "Clinical Trials API error: Invalid NCT ID format",
  "isError": true
}

Development

Building from Source

# Install dependencies
npm install

# Build TypeScript to JavaScript
npm run build

# Development with watch mode
npm run watch

Project Structure

clinical-trials-server/
├── src/
│   └── index.ts          # Main server implementation (all tools)
├── build/
│   └── index.js          # Compiled executable
├── package.json          # Dependencies and scripts
├── tsconfig.json         # TypeScript configuration
└── README.md            # This file

Key Dependencies

@modelcontextprotocol/sdk - MCP server framework
axios - HTTP client for API requests
TypeScript for type safety and development

Data Sources

API Endpoint: https://clinicaltrials.gov/api/v2 Data Updates: Monday through Friday (excluding federal holidays) Coverage: 400,000+ studies from 220+ countries Data Quality: Official FDA/NIH registry with verified information

Troubleshooting

Server Connection Issues:

   # Test server manually
   cd clinical-trials-server
   node build/index.js
   # Should show: "Clinical Trials MCP server running on stdio"

Invalid NCT ID Errors:

Ensure NCT IDs follow format: NCT########
Example: NCT05882279 ✓, nct123 ✗

No Results Returned:

Check search criteria - try broader terms
Some filters may be too restrictive
Verify spelling of conditions and interventions

Timeout Issues:

Server has 30-second timeout protection
Large result sets may take time to process
Reduce pageSize for faster responses

Clinical Research Use Cases

Patient Recruitment: Find actively recruiting trials for specific conditions
Competitive Analysis: Research similar studies by sponsors or interventions
Site Selection: Identify optimal locations for new studies
Regulatory Research: Access FDA-approved study protocols and outcomes
Academic Research: Analyze clinical trial trends and statistics
Patient Care: Help patients find appropriate treatment options

Compliance & Ethics

This server provides access to publicly available clinical trial data from ClinicalTrials.gov. Users should:

Follow institutional policies for clinical research
Respect patient privacy and confidentiality
Use data for legitimate research and healthcare purposes
Cite ClinicalTrials.gov as the data source in publications

License

MIT License - See LICENSE file for details

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Data Source: ClinicalTrials.gov (https://clinicaltrials.gov) API Documentation: https://clinicaltrials.gov/data-api/api Server Version: 1.0.0 Repository: https://github.com/BACH-AI-Tools/ClinicalTrials-MCP-Server

Clinical Trials MCP Server