# ClinicalTrials.gov Search API

> ClinicalTrials.gov Search API is a paid API for AI agents from clinical.memoryapi.org, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-15).

Search ClinicalTrials.gov for clinical trials by condition, intervention, sponsor, status, or phase

## Facts

- Endpoint: GET https://clinical.memoryapi.org/x402/clinical/trials
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/clinical-memoryapi-org-6fb13bec
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Fjc1rS_8XBetmwGWKuAnI

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 clinical-memoryapi-org-6fb13bec
```

Example prompt: Search ClinicalTrials.gov for currently recruiting Phase 3 trials studying pembrolizumab for non-small cell lung cancer — I want to see the list of matching trials with their NCT IDs and sponsors.

## When to prefer this

Use this endpoint when you need to search across the ClinicalTrials.gov database using multiple filters (condition, intervention, sponsor, status, phase) and want a list of matching trials. Prefer this over the sibling detail endpoint when you don't have a specific NCT ID yet and need to discover relevant trials. Prefer this over the aggregate statistics endpoint when you need individual trial records rather than summary counts.

## Known failure modes

- No trials found matching the given condition or intervention — returns empty result set
- Invalid phase or status filter value — returns 400 error
- Payment not included or insufficient — returns 402 Payment Required
- ClinicalTrials.gov upstream unavailable — returns 503 or timeout
- Overly broad query returns too many results — may be paginated or truncated

## How this service works

ClinicalTrials.gov intelligence — search 400K+ trials by condition, intervention, sponsor, or phase. Full trial details, eligibility, outcomes, and aggregate stats. Pay-per-request via x402 on Base mainnet.

## Output

A list of clinical trials matching the search criteria, including trial titles, NCT identifiers, current status, phase, sponsor, and intervention details sourced from ClinicalTrials.gov.

## Example request

```json
{
 "group_by": "status",
 "condition": "diabetes"
}
```

## Request schema (JSON Schema)

```json
{
 "properties": {
  "input": {
   "properties": {
    "method": {
     "type": "string",
     "enum": [
      "GET"
     ]
    }
   },
   "required": [
    "method"
   ]
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "example": {
  "count": 10,
  "total": 1240,
  "trials": [
   {
    "phase": "PHASE3",
    "title": "A Study of Semaglutide in Type 2 Diabetes",
    "nct_id": "NCT03232697",
    "status": "COMPLETED",
    "sponsor": "Novo Nordisk"
   }
  ],
  "success": true
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/clinical-memoryapi-org-6fb13bec/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from clinical.memoryapi.org](https://www.zero.xyz/host/clinical.memoryapi.org/llms.txt)