About ClinicalTrials.gov MCP by usefulapi
A hosted MCP server for searching and reading ClinicalTrials.gov studies, aimed at people researching clinical trials. It provides study lookup alongside field metadata and aggregate statistics, without local installation.
Key features
- 01Search clinical trials
- 02Retrieve studies by NCT ID
- 03Count matching studies
- 04Inspect field values and metadata
- 05View study statistics and API version
Use cases
- 01Find trials matching research criteria
- 02Review a study using its NCT ID
- 03Check field distributions and study counts
MCP support
Exposes read-only ClinicalTrials.gov search, study retrieval, counts, field data, statistics, and API-version tools to MCP clients. It is hosted and connects through its remote MCP endpoint.
Configuration
Remote servers need no local install. Pick your client, then copy the config or install in one click.
https://clinicaltrialsgov.usefulapi.io/mcpclaude mcp add --transport http io-usefulapi-clinicaltrialsgov https://clinicaltrialsgov.usefulapi.io/mcp{"mcpServers":{"io-usefulapi-clinicaltrialsgov":{"type":"http","url":"https://clinicaltrialsgov.usefulapi.io/mcp"}}}Open in Cursor{"servers":{"io-usefulapi-clinicaltrialsgov":{"type":"http","url":"https://clinicaltrialsgov.usefulapi.io/mcp"}}}Open in VS Code{"mcpServers":{"io-usefulapi-clinicaltrialsgov":{"type":"http","url":"https://clinicaltrialsgov.usefulapi.io/mcp"}}}{"mcpServers":{"io-usefulapi-clinicaltrialsgov":{"serverUrl":"https://clinicaltrialsgov.usefulapi.io/mcp"}}}Run commands in a terminal; paste JSON into the client’s MCP config and restart. Servers that need sign-in will prompt on first connect.
Tools
7| Parameter | Type | Required | Description |
|---|---|---|---|
| ids | array | No | Restrict to these NCT ids (maps to filter.ids), e.g. ['NCT00841061']. |
| sort | string | No | Sort order, e.g. '@relevance', 'LastUpdatePostDate:desc', 'EnrollmentCount:desc', 'StudyFirstPostDate:desc'. |
| term | string | No | General full-text 'other terms' query (maps to query.term). |
| title | string | No | Words in the study title (maps to query.titles). |
| fields | array | No | Fields or modules to return, e.g. ['NCTId','BriefTitle','OverallStatus'] or ['protocolSection.identificationModule']. Omit to return full study records. |
| status | array | No | Filter by overall recruitment status (maps to filter.overallStatus). One or more of: ACTIVE_NOT_RECRUITING, COMPLETED, ENROLLING_BY_INVITATION, NOT_YET_RECRUITING, RECRUITING, SUSPENDED, TERMINATED, WITHDRAWN, AVAILABLE, NO_LONGER_AVAILABLE, TEMPORARILY_NOT_AVAILABLE, APPROVED_FOR_MARKETING, WITHHELD, UNKNOWN. |
| sponsor | string | No | Sponsor / collaborator name (maps to query.spons). |
| advanced | string | No | Advanced Essie expression applied as an additional filter (maps to filter.advanced). |
| location | string | No | Study location text, e.g. a city/state/country (maps to query.locn). |
| pageSize | integer | No | Number of studies per page (1–1000; API default 10). |
| condition | string | No | Disease / condition to match (maps to query.cond), e.g. 'diabetes'. |
| geoFilter | string | No | Geo filter as a raw geo-function string (maps to filter.geo), e.g. 'distance(39.0027,-77.1,50mi)'. |
| pageToken | string | No | Opaque token from a previous response's nextPageToken, to fetch the next page. |
| countTotal | boolean | No | Include the total number of matching studies (totalCount) on the first page. |
| intervention | string | No | Treatment / drug / intervention to match (maps to query.intr). |
Details
From the project READMEClinicalTrials.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/mcpto log in. - VS Code: Add to VS Code.
- Cursor and other clients: add the URL as a remote MCP server:
{
"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
| Tool | Type | What it does |
|---|---|---|
clinicaltrialsgov_search_studies | read | Search clinical trials (ClinicalTrials.gov) |
clinicaltrialsgov_get_study | read | Get a clinical trial by NCT ID |
clinicaltrialsgov_count_studies | read | Count matching clinical trials |
clinicaltrialsgov_list_field_values | read | List value statistics for study fields |
clinicaltrialsgov_get_study_metadata | read | Get the study data-model (field tree) |
clinicaltrialsgov_get_studies_stats | read | Get study size statistics |
clinicaltrialsgov_get_api_version | read | Get the ClinicalTrials.gov API version |
clinicaltrialsgov_usage_status | meta | Usage status (free-tier meter) |
clinicaltrialsgov_request_feature | meta | Request a missing feature |
clinicaltrialsgov_upgrade | meta | Upgrade to Pro (unlimited*) |
clinicaltrialsgov_cancel_subscription | meta | Cancel 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
| Plan | Price | Limit |
|---|---|---|
| Free | $0 | 50 tool calls / month |
| Pro | $9/mo or $90/yr (2 months free) | Unlimited* |
*Pro has a fair use limit of 10,000 tool calls a month on this server. For more, write to [email protected].
Pro covers this server only. Subscribe with clinicaltrialsgov_upgrade (it returns a Stripe Checkout link). Cancel any time with clinicaltrialsgov_cancel_subscription: Pro continues to the end of the paid period, with no refund for the current period, and running clinicaltrialsgov_upgrade before then undoes the cancel. Or write to [email protected].
License
MIT
Comments
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