# ClinicalTrials.gov Study Resolver

> ClinicalTrials.gov Study Resolver is a paid API for AI agents from payai.agentstools.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-09-15).

Resolves a single clinical trial by NCT ID and returns a normalized profile including identity, recruitment status, phase, design, enrollment, sponsors, conditions, interventions, outcomes, sites, and key dates.

## Facts

- Endpoint: GET https://payai.agentstools.dev/trials/study
- Price: $0.02/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/clinicaltrials-gov-study-resolver-e7652bc3
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_KRwdfAzknYBY7q9Pg-jYA

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-resolver-e7652bc3
```

Example prompt: Can you pull up the full profile for clinical trial NCT03228186 — I need the recruitment status, phase, lead sponsor, conditions being studied, and primary outcomes?

## When to prefer this

Use this endpoint when you need structured, normalized data for a specific clinical trial identified by its NCT ID, rather than searching across trials. Prefer this over manual ClinicalTrials.gov browsing when you need machine-readable fields like phase, status, sponsors, and outcomes in a consistent format. Ideal for due diligence workflows, research pipelines, or agent tasks that need to compare or summarize individual trial profiles.

## Known failure modes

- Invalid or malformed NCT ID returns an error or empty result
- Trial not found on ClinicalTrials.gov returns 404 or null profile
- ClinicalTrials.gov upstream outage causes timeout or error
- Missing required 'nct' or 'id' query parameter results in a validation error
- Very recently registered trials may have incomplete data fields

## How this service works

Resolve one clinical trial by its NCT id and get a normalized cited profile: identity, recruitment status, phase, study design, target enrollment, lead sponsor and collaborators, conditions, interventions, primary outcomes, trial sites and key dates, plus computed signals from ClinicalTrials.gov.

## Output

A normalized clinical trial profile including: trial identity (title, NCT ID), current recruitment status, study phase, study design parameters, target enrollment count, lead sponsor name and collaborators, conditions studied, interventions being tested, primary outcome measures, geographic trial sites, key dates (start, primary completion, estimated completion), and computed signals derived from ClinicalTrials.gov data.

## 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",
      "HEAD",
      "DELETE"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "id": {
       "type": "string",
       "description": "Alias for nct"
      },
      "nct": {
       "type": "string",
       "description": "A ClinicalTrials.gov NCT id such as NCT03228186"
      }
     }
    }
   },
   "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-resolver-e7652bc3/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from payai.agentstools.dev](https://www.zero.xyz/host/payai.agentstools.dev/llms.txt)