generated: '2026-09-06'
method: derived
source: openapi/_original/clinical-trials-gov-openapi.yml (candidate tools); web search for an official server
status: candidate
name: ClinicalTrials.gov Data API v2 (candidate MCP surface)
description: >-
  A CANDIDATE tool list derived from the ClinicalTrials.gov Data API v2 OpenAPI operations.
  The National Library of Medicine does not publish an MCP server for ClinicalTrials.gov —
  no hosted endpoint, no NLM-owned package, and no reference to MCP anywhere on
  clinicaltrials.gov/data-api. Nothing here is an endpoint an agent can call today.
deployment:
  mode: none
  endpoint: null
  install: null
  package: null
  auth: none
  verified: derived
  note: >-
    mode is none because no first-party server exists. Third-party servers DO exist
    (clinicaltrialsgov-mcp-server on npm, 2.9.3 / 2026-09-03, by cyanheads; plus several
    others found on npm) — they are community stdio packages wrapping the same public REST
    API, and are recorded in packages/clinical-trials-gov-packages.yml. They are NOT this
    provider's agent surface and no endpoint is asserted for them here.
authentication:
  required: false
  note: >-
    The underlying REST API is unauthenticated and the data is U.S. Government public
    domain, so any MCP server over it needs no credential.
tools:
- name: search_studies
  description: Search clinical study records by term, condition, location, intervention, title, status or geography.
  backing_operation: GET /studies
  parameters: [format, query.term, query.cond, query.locn, query.titles, query.intr, filter.overallStatus, filter.geo, fields, pageSize, pageToken, countTotal]
- name: get_study
  description: Retrieve a single study record by its NCT identifier.
  backing_operation: GET /studies/{nctId}
  parameters: [nctId, format, fields]
- name: get_study_field_metadata
  description: List every study data field, its type and its position in the study data structure.
  backing_operation: GET /studies/metadata
  parameters: [includeIndexedOnly, includeHistoricOnly]
- name: list_search_areas
  description: List the named search areas that query.* parameters accept.
  backing_operation: GET /studies/search-areas
  parameters: []
- name: list_enums
  description: List the controlled-vocabulary enumerations used across study fields.
  backing_operation: GET /studies/enums
  parameters: []
- name: get_study_sizes
  description: Distribution of study record sizes in the registry.
  backing_operation: GET /stats/size
  parameters: []
- name: get_field_values
  description: Value distribution statistics for named study fields.
  backing_operation: GET /stats/field/values
  parameters: [types, fields]
- name: get_field_sizes
  description: Size statistics for named study fields.
  backing_operation: GET /stats/field/sizes
  parameters: [fields]
- name: get_version
  description: Report the API version and the timestamp of the last data refresh.
  backing_operation: GET /version
  parameters: []
evidence:
- url: https://clinicaltrials.gov/api/v2/version
  status: 200
  note: 'live unauthenticated probe 2026-09-06: apiVersion 2.0.5, dataTimestamp 2026-09-04T09:00:06'
- url: https://clinicaltrials.gov/data-api
  status: 200
  note: developer portal — no MCP server referenced