# ClinicalTrials.gov Study Search

> ClinicalTrials.gov Study Search is a paid API for AI agents from api.healthtravel-api.workers.dev, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-29).

Searches ClinicalTrials.gov via API v2 and returns up to 10 studies with NCT ID, title, status, phase, dates, sponsor, conditions, interventions, enrollment, and primary outcome.

## Facts

- Endpoint: GET https://api.healthtravel-api.workers.dev/api/health/clinical-trials-gov?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/clinicaltrials-gov-study-search-d2b29a4e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_YvbJzO5BU9lWpLY0vRQOO

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability clinicaltrials-gov-study-search-d2b29a4e
```

Example prompt: Can you search ClinicalTrials.gov for up to 8 studies on Alzheimer's disease and show me their status, phase, and primary outcomes?

## When to prefer this

Use this endpoint when you need structured clinical trial data from the official ClinicalTrials.gov registry, including study status, phase, sponsor, interventions, and outcomes. Prefer this over general web search when you need machine-readable trial metadata for conditions, drugs, or sponsors. It is ideal for healthcare research agents, medical information tools, or anyone needing to audit or explore the clinical trial landscape for a specific topic.

## Known failure modes

- Query string shorter than 2 or longer than 200 characters returns a validation error
- No matching studies found returns an empty results list
- max parameter out of range (1-10) causes an error
- ClinicalTrials.gov API v2 downtime results in upstream failure
- Ambiguous or misspelled search terms may return irrelevant or zero results

## How this service works

ClinicalTrials.gov study search (API v2): NCT ID, title, status, phase, start and completion dates, sponsor, conditions, interventions, enrollment and primary outcome. Up to 10 studies per call.

## Output

Returns a list of up to 10 clinical study records from ClinicalTrials.gov, each containing: NCT ID, study title, current status (e.g. recruiting, completed), phase, start and primary completion dates, lead sponsor name, conditions studied, interventions used, enrollment count, and primary outcome measure.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "q"
     ],
     "properties": {
      "q": {
       "type": "string",
       "description": "Search term (condition, drug, sponsor), 2 to 200 characters"
      },
      "max": {
       "type": "string",
       "description": "How many studies, 1 to 10 (default 5)"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/clinicaltrials-gov-study-search-d2b29a4e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from api.healthtravel-api.workers.dev](https://www.zero.xyz/host/api.healthtravel-api.workers.dev/llms.txt)