# Clinical Trial Search

> Clinical Trial Search is a paid API for AI agents from clinical-trials.use.x402atlas.com, paid per call via x402, $0.01/call, status unknown (last checked 2026-10-29).

Search ClinicalTrials.gov studies by free text, condition, intervention, sponsor, status, and phase, returning structured study metadata.

## Facts

- Endpoint: GET https://clinical-trials.use.x402atlas.com/search?utm_source=zero.xyz
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-29
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/clinical-trial-search-6ab365e9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4RDUIRF2_m00H53hVBHuR

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-trial-search-6ab365e9
```

Example prompt: Can you find recruiting Phase 3 clinical trials for type 2 diabetes testing semaglutide, sponsored by Novo Nordisk? Show me up to 20 results.

## When to prefer this

Use this endpoint when you need to search or discover clinical trials from ClinicalTrials.gov by flexible free-text or structured filters (condition, drug, sponsor, phase, status). Prefer it over the sibling 'Clinical Trial Updates' endpoint when you want broad discovery rather than a feed of recently changed studies. It is ideal for drug development research, patient recruitment use cases, competitive intelligence, and literature review tasks that require structured trial metadata.

## Known failure modes

- Empty result set when query terms are too specific or misspelled — returns count:0 with no studies
- Invalid status value in comma-separated list returns a 400-level error
- Phase enum value not matching allowed options (early1, 1, 2, 3, 4, na) causes request rejection
- Exceeding limit maximum of 50 or providing a malformed page_token causes schema validation failure
- ClinicalTrials.gov upstream unavailability may cause timeouts or empty responses

## How this service works

Clinical trial search — find ClinicalTrials.gov studies by free text, condition, intervention, sponsor, recruitment status and phase, and get each study's NCT id, titles, status, phases, conditions, interventions, sponsor, start and completion dates, enrollment and whether results are posted. Use for drug development, medical research and patient-recruitment questions.

## Output

Returns a paginated list of matching ClinicalTrials.gov studies, each with NCT ID, official and brief titles, recruitment status, phases, conditions, interventions, lead sponsor, start and primary completion dates, enrollment count, and whether results have been posted. Also includes applied filter echoes, total match count, retrieval timestamp, and a next_page_token for pagination.

## 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": [
      "query"
     ],
     "properties": {
      "limit": {
       "type": "integer",
       "default": 10,
       "maximum": 50,
       "minimum": 1
      },
      "phase": {
       "enum": [
        "early1",
        "1",
        "2",
        "3",
        "4",
        "na"
       ],
       "type": "string",
       "description": "early1 = early phase 1; na = not applicable"
      },
      "query": {
       "type": "string",
       "maxLength": 200,
       "description": "Free-text search over all study fields"
      },
      "status": {
       "type": "string",
       "maxLength": 200,
       "description": "Comma-separated, up to 5 of: recruiting, not_yet_recruiting, active_not_recruiting, enrolling_by_invitation, completed, suspended, terminated, withdrawn, available, no_longer_available, temporarily_not_available, approved_for_marketing, withheld, unknown"
      },
      "sponsor": {
       "type": "string",
       "maxLength": 200,
       "description": "Lead sponsor name filter"
      },
      "condition": {
       "type": "string",
       "maxLength": 200,
       "description": "Condition or disease filter"
      },
      "page_token": {
       "type": "string",
       "maxLength": 512,
       "description": "next_page_token of the previous page"
      },
      "intervention": {
       "type": "string",
       "maxLength": 200,
       "description": "Intervention or treatment filter"
      }
     },
     "additionalProperties": false
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "required": [
      "as_of",
      "source",
      "caveat",
      "modified",
      "query",
      "condition",
      "intervention",
      "sponsor",
      "status",
      "phase",
      "count",
      "total",
      "studies",
      "next_page_token"
     ],
     "properties": {
      "note": {
       "type": "string",
       "description": "Present only on a sample 
… (truncated)
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/clinical-trial-search-6ab365e9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from clinical-trials.use.x402atlas.com](https://www.zero.xyz/host/clinical-trials.use.x402atlas.com/llms.txt)