ClinicalTrials.gov MCP by usefulapi

io.usefulapiPublished by usefulapi.ioOfficial publisherv1.40.2Updated Nov 14, 2026

Search and read ClinicalTrials.gov studies, sites and outcomes.

The publisher's own server: Ably MCP by usefulapi

VerifiedStreamable HTTPWeb executableLocation & LifestyleData & Analytics

Overview

AI-generated overview

Hosted MCP server that lets an assistant search, read and count ClinicalTrials.gov clinical studies, sites and outcomes.

What you can do
  • Search studies by condition, intervention, title, location, sponsor, status or advanced expression, and count matches without fetching records
  • Fetch a single study by NCT id, optionally limited to chosen fields or modules
  • Explore the study data model and list valid field values and enums before building filters
  • Read registry-wide size statistics and the API version with data snapshot timestamp
  • Check monthly usage, request a feature, upgrade or cancel a paid plan
When to use it
Useful when you need trial information for a condition, intervention, sponsor or region, eligibility details for a specific NCT id, or counts of registered trials for research or reporting.
Requirements
Remote streamable HTTP endpoint; no local install. Sign-in uses OAuth with an email address and a 6-digit code sent by email. No API key or Authorization header should be added to the client config.
Before you install
Free plan is limited to 50 tool calls per month; paid plans cost $9/month (Pro) or $39/month (Pro+) and are billed through a Stripe Checkout link. Upgrading, changing plan and cancelling are account actions the assistant can trigger, so confirm before running them. Your email address is used for login and stored as a one-way hash.

Installation

In SourceWeft

  1. Open ClinicalTrials.gov MCP by usefulapi in the dashboard and add it to a workspace.
  2. Enable the server for the chats that should use its tools.

Web executable via Streamable HTTP. Remote servers run from the web runtime once configured in a workspace.

Use with an agent

Paste this prompt into Claude Code, Codex, Cursor or another agent — or into SourceWeft chat. The agent reads this server's install guide, shows you its publisher, endpoint and sign-in, and adds it to your client once you agree. Keys never go into a command.

Read https://sourceweft.com/mcp/io.usefulapi%2Fclinicaltrialsgov/install.md and connect the MCP server it describes to my client. Before changing any config, show me its publisher, endpoint and sign-in method and wait for my OK. Never put an API key in a command or in a file I would commit; ask me where it should come from.

Read the install guide the agent follows

Other MCP clients

Add this to your client's mcpServers config.

{
  "mcpServers": {
    "clinicaltrials-gov-by-usefulapi": {
      "type": "http",
      "url": "https://clinicaltrialsgov.usefulapi.io/mcp"
    }
  }
}

README

ClinicalTrials.gov MCP by usefulapi

Search and read ClinicalTrials.gov studies, sites and outcomes. Hosted, no local install.

Live endpoint: https://clinicaltrialsgov.usefulapi.io/mcp · Homepage: https://usefulapi.io

Connect

  • Claude (claude.ai, Desktop): open Customize → Connectors, click + Add → Add custom connector, and paste https://clinicaltrialsgov.usefulapi.io/mcp.
  • Claude Code: claude mcp add --transport http clinicaltrialsgov https://clinicaltrialsgov.usefulapi.io/mcp, then run /mcp to log in.
  • VS Code: Add to VS Code.
  • Cursor and other clients: add the URL as a remote MCP server:
json
{  "mcpServers": {    "clinicaltrialsgov": {      "url": "https://clinicaltrialsgov.usefulapi.io/mcp"    }  }}

Add only the URL. Do not add an Authorization header or an API key to the client config: the server signs you in with OAuth, and the login page asks for your email address and a 6-digit code.

Step-by-step setup, where to find your credentials, and FAQ: https://usefulapi.io/clinicaltrialsgov/

This server needs no credential — ClinicalTrials.gov is a public data source. On first connect you log in with your email: we send a 6-digit code from [email protected]. The address is used only to send the code; we keep a one-way hash of it as your account id, so your free calls and your plan stay yours.

Tools

ToolTypeWhat it does
clinicaltrialsgov_search_studiesreadSearch clinical trials (ClinicalTrials.gov)
clinicaltrialsgov_get_studyreadGet a clinical trial by NCT ID
clinicaltrialsgov_count_studiesreadCount matching clinical trials
clinicaltrialsgov_list_field_valuesreadList value statistics for study fields
clinicaltrialsgov_get_study_metadatareadGet the study data-model (field tree)
clinicaltrialsgov_get_studies_statsreadGet study size statistics
clinicaltrialsgov_get_api_versionreadGet the ClinicalTrials.gov API version
clinicaltrialsgov_usage_statusmetaUsage status (free-tier meter)
clinicaltrialsgov_request_featuremetaRequest a missing feature
clinicaltrialsgov_upgrademetaUpgrade to Pro or Pro+
clinicaltrialsgov_cancel_subscriptionmetaCancel the Pro subscription

read tools are read-only; write tools mutate data (clients should confirm them); meta tools report usage, manage your subscription or send a feature request.

Pricing

PlanPriceLimit
Free$050 tool calls / month
Pro$9/mo or $90/yr (2 months free)10,000 tool calls / month
Pro+$39/mo or $390/yr (2 months free)100,000 tool calls / month

Each paid plan covers this server only. Ask your AI to run clinicaltrialsgov_upgrade and choose Pro or Pro+, billed monthly or yearly (it returns a Stripe Checkout link). If you already have Pro, ask to change it to Pro+. The change requires your confirmation, keeps your billing interval and charges the price difference for the rest of the period immediately. Cancel any time with clinicaltrialsgov_cancel_subscription: your paid plan continues to the end of the paid period, with no refund for the current period, and asking to resume the same plan with clinicaltrialsgov_upgrade before then undoes the cancel. Or write to [email protected].

License

MIT

Source: servers/clinicaltrialsgov/README.md at commit 3c1b3df

Tools

7

clinicaltrialsgov_search_studies

Search clinical trials (ClinicalTrials.gov)

Search the ClinicalTrials.gov v2 study registry. Provide any combination of query terms (condition, intervention, title, location, sponsor, general term) — multiple query.* terms are ANDed together — plus optional filters (status, geo, advanced Essie expression, explicit NCT ids). Returns { totalCount?, studies: [...], nextPageToken? }. Use `fields` to trim the response to specific fields/modules, `sort` to order (e.g. '@relevance', 'LastUpdatePostDate:desc', 'EnrollmentCount:desc'), and pageSize/pageToken to page. GET /studies.

ParametersidssorttermtitlefieldsstatussponsoradvancedlocationpageSizeconditiongeoFilter+3 more

clinicaltrialsgov_get_study

Get a clinical trial by NCT ID

Fetch a single ClinicalTrials.gov study by its NCT id (format NCT######## — the letters 'NCT' followed by digits, e.g. NCT00841061). Returns the full study object { protocolSection, derivedSection?, hasResults? }. Use `fields` to return only specific fields/modules. GET /studies/{nctId}.

ParametersnctIdrequiredfields

clinicaltrialsgov_count_studies

Count matching clinical trials

Return only the total NUMBER of studies matching a query, without fetching any records. Accepts the same query terms and filters as clinicaltrialsgov_search_studies (term, condition, intervention, title, location, sponsor, status, geoFilter, advanced). Returns { totalCount }. GET /studies with countTotal=true and pageSize=1.

ParameterstermtitlestatussponsoradvancedlocationconditiongeoFilterintervention

clinicaltrialsgov_list_field_values

List value statistics for study fields

Discover valid values / enums for one or more study fields. Returns per-field value statistics — for each field: its type, unique-value count and topValues [{value, studiesCount}]. Great for finding valid enum values (e.g. OverallStatus, Phase) before building a filter. GET /stats/field/values.

Parameterstypesfieldsrequired

clinicaltrialsgov_get_study_metadata

Get the study data-model (field tree)

Return the ClinicalTrials.gov study data model as a tree of module nodes (each with name/title/type/children). Use this to explore what fields/modules exist and their nesting, to build `fields` selections or `sort`/filter expressions. GET /studies/metadata.

ParametersincludeIndexedOnlyincludeHistoricOnly

clinicaltrialsgov_get_studies_stats

Get study size statistics

Return overall study-size statistics across the registry: { totalStudies, averageSizeBytes, percentiles, ranges, largestStudies }. Useful for understanding data volume. GET /stats/size.

Takes no parameters.

clinicaltrialsgov_get_api_version

Get the ClinicalTrials.gov API version

Return the ClinicalTrials.gov API version and the timestamp of the underlying data snapshot: { apiVersion, dataTimestamp }. GET /version.

Takes no parameters.

Version history

26
  1. v1.40.2LatestNov 14, 2026
  2. v1.40.1Nov 13, 2026
  3. v1.39.0Nov 12, 2026
  4. v1.38.3Nov 11, 2026
  5. v1.37.5Nov 8, 2026
  6. v1.37.4Nov 7, 2026
  7. v1.36.3Nov 5, 2026
  8. v1.36.2Nov 5, 2026
  9. v1.36.1Nov 4, 2026
  10. v1.36.0Nov 3, 2026
  11. v1.35.1Nov 3, 2026
  12. v1.34.0Nov 1, 2026
  13. v1.32.0Oct 31, 2026
  14. v1.31.0Oct 31, 2026
  15. v1.30.2Oct 30, 2026
  16. v1.30.0Oct 30, 2026
  17. v1.25.0Oct 26, 2026
  18. v1.22.3Oct 25, 2026
  19. v1.22.0Oct 25, 2026
  20. v1.21.0Oct 24, 2026
  21. v1.18.0Oct 23, 2026
  22. v1.16.4Oct 22, 2026
  23. v1.16.3Oct 21, 2026
  24. v1.11.1Oct 9, 2026
  25. v1.10.0Oct 9, 2026
  26. v1.0.0Sep 29, 2026

Score

100% of the applicable checks met

How complete this listing is, computed from the registry entry, the endpoint and public sources. Not a rating of the server and not a statement that it is safe or working today: reachability is a dated check, and no installs or reviews go into the score.

  • Reached in the last 30 daysRequired25 pts
  • Auth declaredRequired10 pts
  • Tools listedRequired15 pts
  • DescriptionRequired15 pts
  • Logo10 pts
  • Documentation15 pts
  • License10 pts

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