# ClinicalTrials.gov

**Canonical:** https://apis.io/providers/clinical-trials-gov/  
**Website:** https://clinicaltrials.gov/  
**APIs profiled:** 6

ClinicalTrials.gov is the U.S. National Institutes of Health (NIH) registry and results database of publicly and privately supported clinical studies of human participants conducted around the world. Operated by the National Library of Medicine (NLM), it provides a modern REST API (data-api v2) that returns study records, study metadata, search areas, and field definitions in JSON. The predecessor classic API remains available for legacy consumers but is being phased out in favor of the v2 API. Data is in the public domain and freely accessible without authentication.

## Kin Score — 33.4 / 100 (thin)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 33.4).

| Facet | Score |
|---|---|
| Discoverability | 64.8 |
| Contract Quality | 44.8 |
| Governance | 54.5 |
| Contract Governance | 54.5 |
| Operational Transparency | 5.3 |
| Developer Ergonomics | 9.5 |
| Commercial Clarity | 28.6 |
| Access Clarity | 28.6 |

Regulatory layer — **Government & Public Sector**: 27.8 (matched via tags).

## Agent readiness — 20.9 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | na |
| MCP Server | no |
| Auth Clarity | no |
| Idempotency | na |
| Error Semantics | no |
| OpenAPI Examples | no |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | na |

## Access

Unknown — onboarding: unknown, pricing: unknown, trial: no (confidence: low).

## APIs (6)

- **ClinicalTrials.gov Classic API** — The Classic API is the legacy ClinicalTrials.gov interface that preceded the Data API v2 and exposes full-study, brief-study, and field-values endpoints with XML, JSON, and CSV ...
- **ClinicalTrials.gov Bulk Downloads** — ClinicalTrials.gov provides bulk CSV and JSON downloads of the full study registry through the data-api download endpoints. These artifacts support large-scale analytics, archiv...
- **AACT Database** — AACT (Aggregate Analysis of ClinicalTrials.gov) is a publicly available relational database of all ClinicalTrials.gov study content maintained by the Clinical Trials Transformat...
- **ClinicalTrials.gov Stats API** — The Stats API from ClinicalTrials.gov — 3 operation(s) for stats.
- **ClinicalTrials.gov Studies API** — The Studies API from ClinicalTrials.gov — 5 operation(s) for studies.
- **ClinicalTrials.gov Version API** — The Version API from ClinicalTrials.gov — 1 operation(s) for version.

## Agentic access (1)

- **Clinical Trials Gov Agentic Access** — 9 operations

## Security (1)

- **Clinical Trials Gov Domain Security** — TLSv1.3 · HSTS · DNSSEC · DMARC

## Tags

Clinical Trials, Government, Health, NIH, Open Data, Public Health, Research

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/clinical-trials-gov/). Scores are computed from the provider's own public artifacts under a published rubric.